Mon Jun 29, 2020 3:41 am

Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
Joined: 14 Jun 2017
Posts: 2869
Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
Joined: 14 Jun 2017
Posts: 2869
Location: London UK
Mon Jun 29, 2020 3:41 am linkquote
There used to be 0.3 head gaskets but they seem to have disappeared from supply.

1.15 squish is not so big. Not ideal but ok.

Option 2 might be worth a go as it's easy. 129 is quite a bit but could work. Now the exhaust is changed would make an interesting test. Will go better at WOT but pulling 4th is the concern. Was it ok on the bad exhaust?
Mon Jun 29, 2020 6:38 am

Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
 
Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
Mon Jun 29, 2020 6:38 am linkquote
I never really got to wind it out in 4th with the old exhaust, as I was getting constant splutter, but it could definitely pull 4th at 129 TD. The spluttery condition was clogged exhaust, not the main jet being too big, so now that's sorted, the higher TD is worth a shot.

Gearbox reminder:
PX125 but with 22T clutch
120/70-11 rear tyre

Calculator below assumes that it can make 9000 RPM in all 4 gears. Possibly not the case in 4th. To be determined if I can find the right road and some spare undies



Mon Jun 29, 2020 7:25 am

Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
Joined: 14 Jun 2017
Posts: 2869
Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
Joined: 14 Jun 2017
Posts: 2869
Location: London UK
Mon Jun 29, 2020 7:25 am linkquote
Sounds like a plan, back to 129. No reason not to now. Now the piston is done as well, so will need a slight upjet at WOT.
I think your gearing works out similar to a 200. On mine I have seen 8700rpm in 4th, so far. Still more in it. No reason yours won't do similar with an expansion pipe.
Although I expect yours will make 8000rpm in 4th even with the box. Well into the scary zone.
Tue Jun 30, 2020 12:14 pm

Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
 
Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
Tue Jun 30, 2020 12:14 pm linkquote
Jack, did you take anything off the piston skirt to account for the 60 stroke, or is that something that people only needed to do on the older 210 kits/pistons?
Tue Jun 30, 2020 6:33 pm

Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and new to 2018, '66 Blue Badge Smallframe
Joined: 30 Nov 2011
Posts: 8089
Location: Victoria, Australia
 
Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and new to 2018, '66 Blue Badge Smallframe
Joined: 30 Nov 2011
Posts: 8089
Location: Victoria, Australia
Tue Jun 30, 2020 6:33 pm linkquote
swa45 wrote:
Jack, did you take anything off the piston skirt to account for the 60 stroke, or is that something that people only needed to do on the older 210 kits/pistons?
Pretty sure the initial 2016 release pistons needed it, but the newer ones (with the black coating) don't.
Tue Jun 30, 2020 9:06 pm

Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
Joined: 14 Jun 2017
Posts: 2869
Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
Joined: 14 Jun 2017
Posts: 2869
Location: London UK
Tue Jun 30, 2020 9:06 pm linkquote
Ginch wrote:
swa45 wrote:
Jack, did you take anything off the piston skirt to account for the 60 stroke, or is that something that people only needed to do on the older 210 kits/pistons?
Pretty sure the initial 2016 release pistons needed it, but the newer ones (with the black coating) don't.
New pistons are shorter. And it was running already
Tue Jun 30, 2020 10:13 pm

Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
 
Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
Tue Jun 30, 2020 10:13 pm linkquote
Cheers chaps. Yes, it has been running without any contact. Was just thinking of anything else I needed to do while I was in there.
Fri Jul 24, 2020 1:09 am

Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
 
Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
Fri Jul 24, 2020 1:09 am linkquote
Fuel pump issues
The 'slightly improved' engine (Dremeled piston, viton clutch-side seal and new crank) goes really well, but I'm having problems with the fuel pump. It was working fine before, but now it appears to be completely kaput. The vacuum pipe is blowing out air if detached from the pump. I thought it was supposed to suck, give that we're creating a vacuum? Anyway, fuel is not climbing the slope to the carb, so float chamber empties and scoot comes to a halt.

Are the Mikuni pumps prone to failure and are there any tests that I can do?
Fri Jul 24, 2020 1:29 am

Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
Joined: 14 Jun 2017
Posts: 2869
Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
Joined: 14 Jun 2017
Posts: 2869
Location: London UK
Fri Jul 24, 2020 1:29 am linkquote
The pump line does blow and suck if connected under the reeds. Would seem normal.

Squirt the pump into a bucket and see how much it delivers. They do fail and even the slightest vac leak will weaken it.
Fri Jul 24, 2020 6:00 am

Molto Verboso
Vespa
Joined: 19 Jun 2007
Posts: 1323
Location: California
 
Molto Verboso
Vespa
Joined: 19 Jun 2007
Posts: 1323
Location: California
Fri Jul 24, 2020 6:00 am linkquote
Recently replaced the diaphragm/gasket on my pump due to air bubbles in the output. Simple to do and fixed.



Thu Jul 30, 2020 2:16 am

Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
 
Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
Thu Jul 30, 2020 2:16 am linkquote
Thanks Hibbert, I ordered a Mikuni gasket and diaphragm set just in case, but have since discovered that the problem was a kink in the line from tank to pump which only occurred as I lowered the tank into position. I had used 8mm ID braided fuel injection hose from tank to an 8mm > 6mm reducer, and then 6mm ID to the pump inlet, but I have now invested in 3 metres of Freeline 6mm ID fuel line, which I understand to be some of the best out there. I'll be re-plumbing the whole lot this weekend to be on the safe side. I can just about get 6mm ID line onto the BGM Fast Flow tap, but it's a tight fit.

Scooter goes like a demon on fire, and I'm almost wishing that I'd upgeared it during the maintenance window. On the other hand, I probably just need to get comfortable taking it to 7500 RPM and beyond. I'm so used to the lazy, low rev characteristics of the Pinasco 225 tourer !!

[edit] I meant 7500 in 4th which = 75mph. No doubt I'm getting above 8000 rpm through the gears, but it's 4th gear WOT where I perhaps need to be braver

Last edited by swa45 on Thu Jul 30, 2020 8:36 am; edited 1 time in total
Thu Jul 30, 2020 7:34 am

Molto Verboso
2007 Stella 225
Joined: 02 Nov 2019
Posts: 1782
Location: Rochester, Minnesota
 
Molto Verboso
2007 Stella 225
Joined: 02 Nov 2019
Posts: 1782
Location: Rochester, Minnesota
Thu Jul 30, 2020 7:34 am linkquote
swa45 wrote:
Thanks Hibbert, I ordered a Mikuni gasket and diaphragm set just in case, but have since discovered that the problem was a kink in the line from tank to pump which only occurred as I lowered the tank into position. I had used 8mm ID braided fuel injection hose from tank to an 8mm > 6mm reducer, and then 6mm ID to the pump inlet, but I have now invested in 3 metres of Freeline 6mm ID fuel line, which I understand to be some of the best out there. I'll be re-plumbing the whole lot this weekend to be on the safe side. I can just about get 6mm ID line onto the BGM Fast Flow tap, but it's a tight fit.

Scooter goes like a demon on fire, and I'm almost wishing that I'd upgeared it during the maintenance window. On the other hand, I probably just need to get comfortable taking it to 7500 RPM and beyond. I'm so used to the lazy, low rev characteristics of the Pinasco 225 tourer !!
I've contemplated removing the seat and plastic breather so I could take a picture of the hose with my camera to see what it looks like with the new hose I installed.
Thu Jul 30, 2020 1:57 pm

Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
Joined: 14 Jun 2017
Posts: 2869
Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
Joined: 14 Jun 2017
Posts: 2869
Location: London UK
Thu Jul 30, 2020 1:57 pm linkquote
I would hope you're getting nearer 9,000rpm in 3rd. I can't get mine quite there in 4th but one you get used to the rpm, it's not really revving so high. Used to 15,000rpm on my sports bikes.
Anything over real 70mph on a classic scooter is getting scary. If you let yours go it should make real 85mph everytime but this is way past dangerous. If you have a camera take us for a ride.
Thu Jul 30, 2020 11:32 pm

Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
 
Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
Thu Jul 30, 2020 11:32 pm linkquote
Yeah, I suppose it's got a few miles on it now, without any real incidents. Gonna be hot today so will definitely go for a ride. I have a cheap go pro type camera, but mounting it properly would be my main issue.

The noise from the reed is very loud, so it makes it seem like it's on the edge, even at 65 mph, and that's only 6600 rpm according to the gearing calc.......and only at half throttle. Getting it to WOT and beyond 8000 rpm in 4th will be a test of my nerves. My younger self would have done it in a heartbeat.
Tue Aug 04, 2020 10:33 pm

Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
 
Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
Tue Aug 04, 2020 10:33 pm linkquote
Nice bit of plumbing?
Put my OCD to full use yesterday and tidied up the fuel pump plumbing. The flow just wasn't good enough, particularly once the tank went onto reserve, and I wondered if the BGM tap was defective. I suspect my pulse is not the strongest due to the vacuum line run of ~17 inches/43cm from the crankcase barb to the pump. Excessive, but as mentioned before, this is only a Vespa after all.

Starting with a quality 6mm ID fuel line from a karting specialist, I cut the runs to be as short as possible, and used the tails of the 'T' pieces to carry the pressure relief line between pump inlet and outlet. Due to the previous line being way more rigid, I'd had to use the tails to carry the line from the tank to pump and from pump to the carb, so I had 90 degree turns at crucial points in the flow path.

I used a new 5mm ID vacuum line from a car spares place, and for good measure, I replaced the gaskets and diaphragm in the pump. I'm pretty sure the pump was fine, but I'd bought the repair kit and ideally don't want to go back under the tank any time soon.

With only a small amount of fuel back in the tank, the line and float chamber filled immediately. Big improvement and it looks like I can now run the tank down to near empty if I wanted to. Big improvement and well worth the effort. For those that are thinking about running a big carb and pump, pay attention to the details



Tue Aug 04, 2020 11:51 pm

Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and new to 2018, '66 Blue Badge Smallframe
Joined: 30 Nov 2011
Posts: 8089
Location: Victoria, Australia
 
Veni, Vidi, Posti
74 Super, 75 Super, PX project, LML off-roader and new to 2018, '66 Blue Badge Smallframe
Joined: 30 Nov 2011
Posts: 8089
Location: Victoria, Australia
Tue Aug 04, 2020 11:51 pm linkquote
I found with my pump that length of vacuum line or type didn't make much difference.
Wed Aug 05, 2020 12:17 am

Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
 
Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1729
Location: UK (South East)
Wed Aug 05, 2020 12:17 am linkquote
Yeah, I'm inclined to agree with you Ginch, although I had been using a generic silicone line, which I suspect was collapsing at the bends. Not so with the proper vacuum line. The pulse seems pretty good, but without knowing what it should be to pump fuel effectively, I'm just guessing. Is there a minimum requirement and what unit of measure would that be? PSI? I suppose the only measure that really counts is the rate at which fuel comes out the other end. That and ensuring you're not overwhelming the carb needle seat with too much pressure. I have the seemingly tried and tested spark plug cap in the return/relief line to protect against that.
Wed Aug 05, 2020 12:26 am

Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
Joined: 14 Jun 2017
Posts: 2869
Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
Joined: 14 Jun 2017
Posts: 2869
Location: London UK
Wed Aug 05, 2020 12:26 am linkquote
Nice job. The pumps flow too much anyway, hence the need for the bypass.

The volume of the vacuum pipe reduces crankcase pressure. This is good on a Malossi 221. Not much but it all helps.
  DoubleGood Vespa T-Shirts  

All Content Copyright 2005-2021 by Modern Vespa. All Rights Reserved.

Modern Vespa is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com.

Shop on Amazon Smile with Modern Vespa

[ Time: 0.1462s ][ Queries: 28 (0.1264s) ][ Debug on ][ 201 ][ Thing Two ]