GT200 with Malossi 218, 4v, cam, lv4road. No change?
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Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Tue Dec 26, 2017 5:28 am quote
Oh, and the bathroom fitting that hangs out the back (original Piaggio) takes the original topbox, but I use a wingbolt to fit it now from the inside which makes fitting a 10 second job with my fingers rather than a 5 minute one involving looking for spanners.
Ossessionato
GTS300 Super Blue Gaiola
Joined: 01 Nov 2005
Posts: 2524
Location: Sydney, Australia
Tue Dec 26, 2017 1:05 pm quote
I preferred mine with the topbox off, but found the topbox too useful. So I had two plastic carriers, one for mounting the topbox and the other chopped off and filled in at the back for when I didn't want the box.

I agree with you about the upward-looking headlight. Your visor offsets this a bit, but I would prefer a visor that followed he curve of the headlight. I just have a chrome rim on my present scooter.

GT200-mods2.jpg

GT200 B.jpg
Carrier with no plumbing - much neater.

Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Tue Dec 26, 2017 6:41 pm quote
Very tidy and very GT. I especially like what you did with the tail light.

I don't mind a little bathroom wear though, not too much. The fenders have saved paint when squeezing through tight spaces more than once. I was going to do exactly what you did with the rear rack. When I finally got around to it I found the GTS underseat bracket fitted ($35) along with the Piaggio topbox rack so I did that instead. I wouldn't have done it when it was new, but it got very close to being sold and was looking very unloved so I decided I'd give it a cuddle and see if I could get attached to it again. I'm very pleased with the results, but as I said, there were somethings I just never liked when it was stock.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Wed Dec 27, 2017 10:07 pm quote
Though I'm happy (that's not really strong enough) with my performance now, the original variator is a bit random when it selects rpm. So I've bought the Malossi but not fitted it yet. I'm proposing to fit 3 of the Malossi 14g rollers and 3 of the original 11g giving an average of 12.5g which after reading an old post from a chap with the same set up seems a fair starting point. I'll let you know how I go.

I'm not convinced the airbox doesn't start to get restrictive again over 9k rpm so this will be an interesting test. It definitely pulls very hard at 8600.
Ossessionato
GT200 & GTS250 & NC750X & Royal Enfield Pegasus
Joined: 23 Aug 2013
Posts: 2040
Location: London
Thu Dec 28, 2017 2:53 am quote
Is there any chance of an executive summary to all this?

Something that says adding this item costs so much, took so long to fit and gave these results and perhaps mention any downsides. For many of us that haven't gone down this route it seems that adding performance parts is more of a hobby in itself rather than done purely for the end results. Also what was the overall cost and the end result when compare to stock? would it of been better to swap up to a GTS250/300?
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Sat Dec 30, 2017 1:50 am quote
Yep, I'll do that robinm when I think I have everything the way it should be.

Today when I went to fit the Malossi variator I found that all that extra fun had destroyed the belt. I doubt it would have made another 1km round trip to the shop. I suppose it's lucky I found it. I don't think that the torque and rpm destroyed the belt by themselves, it was looking pretty perished even though it seemed ok when I last looked at it. My guess is the rubber had broken down but it took a sound thrashing with extra heat to show up.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Sat Dec 30, 2017 2:46 am quote
As a summary so far, there wasn't any individual thing that caused eye bulge, they all had to be done together. I can't comment on the importance of the LV 4road exhaust as I fitted that maybe 12 years ago and it didn't make much if any difference to the stock engine, but sounded much better.

The Malossi V4 head/cam/218 cylinder cost $1300AU, maybe $1000US and made little difference on their own as the rpm was too low for the power band and the carb wasn't jetted correctly.

When I lightened the original rollers (no cost if you have an 11.5mm drill, I have a lathe which made it easier) there was a big improvement, but it still leaned out. When I replaced the main jet (after many tries) with a 100 (cost $10AU) it started to go, but I still couldn't balance the mixture. When I drilled 2X7/8" holes at the bottom of the airbox tube, it finally went off.

So total cost was $1010US, and another $200US when I get the Malossi variator on. I will use a set of weights I have that are standard GT200 combined with the Malossi 14g ones to average 12.5g. I paid $15US for the standard weights.

An old GT200 is worth about $2000US, so for $3210 all up it's a pretty exciting Vespa. I rode a GT300 (about $9500AU) and couldn't get excited at all, so for me, resurrecting an old friend has been worthwhile.

Labour for fitting the Malossi kit was $500US, the rest I did myself, but if you had someone else do it I can't imagine it being more than another few hundred bucks. By far the most of my time was spent balancing variator/carb/airbox, but you could just do what I finally did and it would be done in a couple of hours max.

The result, at this point before I change the variator is nothing less than astonishing. Acceleration is handlebar gripping quick, and I climb hills I used to at 60kmh, at 80kmh and still accelerating.

It feels exactly like a stock GT200, and sounds like one, below half throttle, though half throttle feels like full used to. Everything happens in the upper half, which is excellent, because when I just want to tootle through a village it's as scooter as a scooter can be. The revs are a little higher, but really I don't notice. When I open it up it's like a different bike altogether, it roars and takes off. The GT300 I rode did not do that at all, it just rattled and went a little quicker than mine when stock.

I'm a bit concerned about the broken up belt, but I really think that is age rather than torque destruction. I'll give an update when the new variator is fitted with the average 12.5g weights, and again at the next service to see how the new belt has held up.
Ossessionato
LXV 150 Midnight Blue (SOLD)
Joined: 06 Dec 2010
Posts: 2620
Location: Bangkok
Sat Dec 30, 2017 3:06 am quote
Caketin wrote:
... I have a lathe which made it easier ... when I get the Malossi variator on...
Before you put the variator on will you measure the pulley angle for me? Just for my notes. Std. is or should be 15 degrees.
Molto Verboso
2017 GTS300 Supersport (The Yella 'Un aka The Sting)
Joined: 13 May 2017
Posts: 1914
Location: UK, EU
Sat Dec 30, 2017 3:08 am quote
Caketin wrote:
I'm a bit concerned about the broken up belt, but I really think that is age rather than torque destruction. I'll give an update when the new variator is fitted with the average 12.5g weights, and again at the next service to see how the new belt has held up.
Yeah, keep us updated. I'm interested in how it all holds up.
Ossessionato
GT200 & GTS250 & NC750X & Royal Enfield Pegasus
Joined: 23 Aug 2013
Posts: 2040
Location: London
Sat Dec 30, 2017 8:52 am quote
Caketin wrote:
As a summary so far...
Excellent summary! Thanks.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Sat Dec 30, 2017 7:31 pm quote
waspmike, the variator pulley angle is the same as stock. I presume it has to be because the V belt is a 30deg included taper and the old pulley half is still used. Where the change is is in the internal ramp angles for the rollers. This is hard to measure as it is shaped like a parabola. Heavier weights are needed as the angle is more course than the standard one. The variator halves open wider so 1st gear is lower. I believe they close up more too giving just a little extra gearing at the top.

The wear marks on the old variator show that the belt doesn't get close to the centre of the tapered section, in fact it's a good 10mm off. It gets within about 3mm of the O.D. though. The Malossi chart shows their variator leaving the clutch at 20kmh/6500rpm. That compares to the standard 30kmh/5500rpm which is a significant difference I presume caused by the belt riding lower in the drive pulley. It probably explains the shorter belt life too as it has a much tighter corner to go around, is under more tension due to the contra spring, and will generate more heat from torque as well. Even with a stock engine the torque will be much higher if the belt is lower in the pulley.
Ossessionato
GTS300 Super Blue Gaiola
Joined: 01 Nov 2005
Posts: 2524
Location: Sydney, Australia
Sat Dec 30, 2017 8:41 pm quote
That is why I get wheelies now since I fitted the slightly shorter GT200 belt to my 300. It gives a slightly lower low gear and a higher high gear, so I gain at both ends.

And I have no more danger of the belt rubbing on the transmission housing.

But your comment about more wear due to increased bending is something I must bear in mind. I do have some fine black powder in the transmission, indicating some belt wear is taking place.

Mike
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Sat Dec 30, 2017 10:04 pm quote
I can see how that might happen on the 300 as all the torque is in the area the clutch would grab with a shorter belt. I doubt it will work for me as mine is a fair bit higher, but I can live in hope .

The stock GT300 I rode felt restricted. I suspect there is a lot to be got out of one with much more modest work than I've put in.
Ossessionato
LXV 150 Midnight Blue (SOLD)
Joined: 06 Dec 2010
Posts: 2620
Location: Bangkok
Sat Dec 30, 2017 10:41 pm quote
Caketin wrote:
waspmike, the variator pulley angle is the same as stock. I presume it has to be because the V belt is a 30deg included taper and the old pulley half is still used.
But you did measure? Right. But you say the Malossi pulley half has a variable taper?

Some Japanese variators use 14 degrees. Some even 13.5 it depends on application. I use something like this.



The belt will wear asymmetrically until bedded in. As for belt wear from bending the stock Piaggio belt for GT200 (Piaggio #840908 Mitsuboshi #2772071) is segmented on both sides!

Last edited by waspmike on Sat Dec 30, 2017 10:53 pm; edited 1 time in total
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Sat Dec 30, 2017 10:51 pm quote
Hmmm, that's very interesting waspmike. All I did was hold the two against one another in opposite directions to see if they prescribed a straight line, and they did. I don't have a straight edge style protractor, but I will do my best before I install it.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Sat Dec 30, 2017 10:53 pm quote
Sorry, just to clarify, the variable tapper is on the inside where the rollers run.
Ossessionato
LXV 150 Midnight Blue (SOLD)
Joined: 06 Dec 2010
Posts: 2620
Location: Bangkok
Sat Dec 30, 2017 11:00 pm quote
Ok now I see.

Did Malossi come with a new centre boss? Just wondering how they get the pulleys further apart? If the pulley is machined to give extra, that applies at all speeds? Maybe their weights are slightly smaller and this is where the extra comes from. Might also be combined with the steeper ramp angle you noticed? But then the ratios would change quicker at the top end?

Some use a longer boss the achieve the same thing which has to be recovered by using a steeper pulley angle.

BTW Malossi belts are usually wider so what you gain on the roundabouts, you lose on the swings.

CVT's are fascinating
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Sat Dec 30, 2017 11:38 pm quote
I'm guessing here as I've stopped playing with it until I get another belt. I do know the rollers are the same size as standard GT200 ones, but smaller than the GTS (20X17 v 21X17).

If the ramp on the roller tracks is longer then it can also be able to be higher thus pushing the pulleys further apart as well as allowing them to come closer together. The centre bush supplied is actually shorter than the original, which is a little confusing but I haven't checked out how the spacer washers are used yet.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Sun Dec 31, 2017 12:31 am quote
Okay,

I've had a quick comparison of the two variators (couldn't resist) and here's what I've noticed.

Though the centre bush on the Malossi is shorter, it protrudes 1mm further when the rollers are in the centre position (low gear). This is because this variator allows the pressed plate to go much lower into the cast housing. This extra 1mm would let the belt move closer to the centre giving a lower first gear. 1mm doesn't sound like a lot, but on a 15deg ramp (and not being very good at trig) that would equate to maybe 3-4mm radius, or in other words, use up most of that spare 10mm of pulley I had unused in the middle.

As a rough guide, the original wear spot was 20mm from the centre of the shaft. The new one should be around 16mm. Given the belt is a fixed length, it has to ride proportionately higher on the driven pulley too, though that ratio change would be much less so I wont worry about it here.

Consequently, the original drive pulley was 40mm diameter, the new one should be 32mm. Adding just a smidge for the effect on the driven pulley that would be around 20% lower, or 20% more torque for any given rpm, but as the clutch engages at belt speed not engine speed then the engine would also be producing more torque at the elevated rpm. So Engine torque with the kit is 20% higher at 6500 than the original at 5500, plus the gearing advantage of 20% and you do have a rather better launch, in theory at least.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Tue Jan 02, 2018 2:17 am quote
Fitted the Malossi with the 14g/11g weights and get a consistent 8700rpm, which is right where it should be.

Acceleration is better, but only by a bit compared to my 9.3g in the standard variator. It's better when it gets it's skirts up though.

What did worry me was I couldn't fit the spacer washer on the variator anymore, even though I ran the engine for a spell and tried to re-torque it. This isn't mentioned in the Malossi instructions, though they really aren't very good. I've marked the nut and seat to see if they move.
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Granturismo 218
Joined: 04 Feb 2013
Posts: 5146
Location: South Carolina
Tue Jan 02, 2018 4:08 pm quote
Caketin wrote:
What did worry me was I couldn't fit the spacer washer on the variator anymore, even though I ran the engine for a spell and tried to re-torque it. This isn't mentioned in the Malossi instructions, though they really aren't very good. I've marked the nut and seat to see if they move.
Where does this spacer washer go on the variator?
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Tue Jan 02, 2018 4:22 pm quote
It was originally on the outside directly under the nut, with a thinner washer under that. In the Vespa manual I couldn't find a photograph of either that one, or the one under the clutch nut to make sure they are correct. Plenty of people have had a fiddle with it in the past, so it's possible they weren't right to start with.
Ossessionato
LXV 150 Midnight Blue (SOLD)
Joined: 06 Dec 2010
Posts: 2620
Location: Bangkok
Tue Jan 02, 2018 7:17 pm quote
Caketin wrote:
What did worry me was I couldn't fit the spacer washer on the variator anymore,
Now we know where the extra distance came from.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Tue Jan 02, 2018 11:37 pm quote
Okay, I need help. I've obviously pulled it apart so many times I've got confused. The item concerned is a spacer, 15mm ID 5mm thick that is supposed to go under the clutch nut and washer according to diagrams I can find. All that is protruding is the 12mm thread, and not enough of it to get the spacer on, and even if I did the diameter isn't right?
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Wed Jan 03, 2018 12:15 am quote
Struth, I've been responsible for high stoogery. Note to self:- don't work in the dark. So though I laid all the washers and spacers out in the order they came off, I neglected to note the 5mm spacer goes "INSIDE" the transmission case between the bearing and the shoulder.

I didn't ride it much because it was haunting me. I noticed the gear shaft had about 6mm float, which a 5mm spacer makes 1mm float. Idiot.
Ossessionato
GTS300 Super Blue Gaiola
Joined: 01 Nov 2005
Posts: 2524
Location: Sydney, Australia
Wed Jan 03, 2018 2:19 am quote
So you are learning an awful lot the hard way, just as the rest of us did. We have all made silly mistakes (like putting the transmission together and then seeing the clutch bell lying next to you, or forgetting to tighten the crankcase oil filler plug - done that about three times.)

Mike
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Wed Jan 03, 2018 2:41 am quote
Yep, that's pretty much it Mike.

It doesn't matter how many mechanical things I break down and put back together, there's always something new to be careful of. American stuff seems rough compared to European stuff, but at least you only need two spanners and a bit of intuition. Australia doesn't make anything mass produced anymore, but we used to lay somewhere in between.

I didn't ride it far because the rear wheel felt just a little bit tighter that it did before, luckily.

It's a nice balance now between a scooter and a cafe racer. There's a few more ponies that could be extracted, but I like the feel at the moment. I haven't tested it for full speed, but as I said before, that's less important. I know it gets to 80kmh in a flat 6 seconds now, which is a lot more fun than the 10 it used to take.

What I've done three times, is put the carb back together and found the spring next to me.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Sat Jan 06, 2018 12:36 am quote
Next update.

The belt has settled in and now it's 9-9200rpm at WOT. Acceleration has improved a smidge, but I think (sadly) I now need to go back to induction tuning for the higher rpm. When I did it last it was 8200-8600WOT, now it's higher it seems to be running out of breath. This doesn't mean it's slowed down, just the crackle has gone out of the exhaust note, which means there's some hp left.

I'm guessing the airbox has become the problem again as I tried running with it off, and this time it made it through midrange weakly, and perked up at WOT, but lean I suspected. I lifted the needle and it was worse midrange, so in other words it was richer with the airbox off at half throttle, but probably richer with it on at full.

The airbox has a tube in the center around 30mm diameter. This must be a built in restriction and one I think it likes. The original airbox throat was only 2/3rds that in area, though with the extra 22mm X 2 off holes it should be exceeding the tube but probably with more turbulence. So I'm going to start taking out material until the tube is the only significant restriction. I'm only trying to get the same breath in there it used to be happy with at 8500.

An example of why I think this may be the case is the last 1/4 throttle was where the power came on at 8500. Now it's mostly full noise by 3/4 throttle with the last bit not doing much. I'm reasoning this is due to the airbox making it rich over about 9000rpm.

It is seriously faster than stock but just as rideable at idle to half throttle though so don't let this discourage anyone from playing.
Addicted
250 gts, nitroed zip 69cc " the teenager", 200 now 300 lc zip "all grown up"
Joined: 31 Jan 2014
Posts: 720
Location: Cheshire
Sat Jan 06, 2018 1:23 am quote
Hi I have just read your posts,
The Cv carb thatís fitted to your scooter is the limiting factor for extracting full power from your leader / Malossi set up.
The CV carb needs a restrictive induction for it to operate, no one has to my knowledge ever managed to run a open or pod filter with any success.
I have taken the leader engine to its max over years of development and posted my results on this forum.
If you fit a Malossi phf34 carb kit fit a 70 mm trumpet intake bell and run a ram air trumpet sock you will unlock 4-5 bhp at take off and mid range - welcome to wheelie city 😁

Caution

This will probably unlock your quest for the ultimate tuning level of your scooter ( over 100 mph gps ) so be prepared to shell out $$$$$$ís

Have fun

Cheers
ATB
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Sat Jan 06, 2018 5:49 am quote
Three cheers for you having finally turned up. I've been baiting for some nut that has tried to milk a leader with conviction. Thanks for your post. I agree that it has been very difficult for me to get the last few hp out of it, so your post is very timely.

Can you give me a link to your mentioned posts? I've searched tirelessly for just such a thing.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Sun Jan 07, 2018 1:37 am quote
After too much internet time, I now understand why CV carbs just need restriction. That doesn't mean they need a lot of it all the time, but it seems impossible to get an even mixture through the range with anything other than this restriction.

Basically it's just needed to lift the diaphragm, which is an awful compromise as who want's their engine to spend it's time sucking?

So I now understand your suggestion to leave the world of CVs and go to a throttle controlled slide.

I may have just lucked on my set up which is a pretty good compromise. It's ordinary in the midrange, weak if bogged, but very potent above 1/2 throttle. I think I should be able to get that extended just a bit further into the rpm with a smidge more free air though. I'll use Motavista's plugs in the airbox to give me reversible options.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Mon Jan 08, 2018 1:47 am quote
I must have offended everyone, or being not interesting at all because I seem to be alone here.

I'm very interested in anyone else who has played with the Malossi kit and a cv carb. I've found it a tight rope walk, and am interested in the alternate carb suggestion but I've experienced sufficient unpleasantness with the horrible induction crackle of the GT and a pod that I know I won't be able to put up with that. So for now, the airbox and Walbro stays.

The main problem is only bogging at clutch grab, and it's probably not as bad as it was stock, I've just got used to leapy performance now. It's not like I'm doing 1/4miles off the mark very often, most riding is between 50 and 100kmh which is fantastic compared to how it was.
Ossessionato
GTS300 Super Blue Gaiola
Joined: 01 Nov 2005
Posts: 2524
Location: Sydney, Australia
Mon Jan 08, 2018 2:38 am quote
What do you mean by bogging at clutch grab? If the clutch is grabbing before the engine has worked up enough revs for a good take-off, then the solution is Malossi clutch springs. They come with three grades in a set - white 10% stiffer, yellow 30% stiffer and red 60% stiffer. I use the red ones.

An alternative is the Dr.Pulley HIT clutch, but I have no experience with that.

NB. I didn't scan through your previous posts to see whether you already have Malossi clutch springs.

Mike
Ossessionato
LXV 150 Midnight Blue (SOLD)
Joined: 06 Dec 2010
Posts: 2620
Location: Bangkok
Mon Jan 08, 2018 3:22 am quote
Some J Costa variator applications have a dip at about 20 kph when the clutch "grabs". They drop about 1-1.5hp at which comes back at 30 kph.
You just need to raise the stall speed a bit as Mike (first) says.
On my Honda I did this by drilling out the stock shoes/weights.
Buying other springs would be easier.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Tue Jan 09, 2018 4:53 am quote
Firstly I should say that I am very content with what it's doing now.

So many times I've read through threads where people have modified this or that and seem to be dissatisfied at the end and still in search of some elusive goal. Usually they just stop posting at some point and leave me wondering how it all went.

That is not the case here. As motavista said early in this thread, before and after the Malossi kit is night and day. If it isn't you just need to tinker a bit and it will explode out of nowhere.

It is a fussy set up and requires the right rpm and breathing, but that's not expensive to achieve.

In my case the total joy in belting out of a corner at WOT is worth every bit of effort I've put in. The only reason I'm still playing is because now I've tuned my brain into how it works, I'm a little obsessed. When I heard it crackle into life for the first time my ears got tuned in to what it truly sounded like in tune. It goes like a shower of shit, but I can feel it robbing itself of something at 9100rpm.

So fiddle I will until it crackles to full speed.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Tue Jan 09, 2018 5:05 am quote
To answer the clutch grab issue, I haven't been able to tune the carb for low rpm, so it tends to bog when it gets under 6krpm. No worse than it did stock, but when I get eye bulge at 30kmh+ I notice the bog a lot more.

Clutch grab is around 5500rpm, but it always bogs under that when it engages.

Realistically, this only matters once in a ride unless I'm drag racing someone, which at 52yo I try to resist, but don't always.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Thu Mar 08, 2018 9:55 pm quote
A few months on and I've changed the main jet for a 105. I did this because after about 3/4 throttle not much happened. It has worked, now the last 1/4 gives extra rpm and pull. We are lucky with the Vespa as the torque driver responds to torque, so if you have a tach you get an rpm reading that tells you whether things have improved. The torque driver will allow the engine to rev harder if there is enough torque to fight the contra spring. This is a heaven sent for tuning.
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Granturismo 218
Joined: 04 Feb 2013
Posts: 5146
Location: South Carolina
Thu Mar 08, 2018 10:11 pm quote
Mikuni TM33-8012. It's magic.
Hooked
GT200
Joined: 12 Nov 2017
Posts: 112
Location: Darlington Western Australia
Fri Mar 09, 2018 1:25 am quote
Thanks heaps, I'll look it up. Do you have a definition for "Magic"?
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Granturismo 218
Joined: 04 Feb 2013
Posts: 5146
Location: South Carolina
Fri Mar 09, 2018 7:20 am quote
In terms of tuning the engine, until I added the carb, the biggest gains, in order were from:
Malossi Cylinder and Head Kit
Variator
Pipe
Final Drive Gears

all the other stuff.

I would put the Mikuni ahead of the pipe.

Andy suggested the DellOrto 36, and Malossi offers a Dellorto 34 for this engine, but when Malossi came out with the 218cc typhoon race bike, they switched to this carburetor, and Mikuni is a lot more common in the US than DellOrto.

It's great right out of the box. Acceleration is improved in the mid-range, the jetting is pretty good throughout the throttle range, according to the air/fuel sensor I have, and the bike maintains about 5 mph faster than before.
The problem a lot of people have when they try to put a flat slide carb on one of these bikes is that most of the cheap ones on the market are for two stroke scooters. This one was an OEM carb for the Suzuki DR350, and it has an accelerator pump. I think any 32-36 mm flat slide carb from a four stroke enduro or dirt bike would probably work fine, if it fits, but Malossi chose this carb out of the options available to pair with the 218cc kit, and I'm sure they did a bit of research first.
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