Reed valve repair for wrecked rotary pad - P200
Post Reply    Forum -> Not-So-Modern
Author Message
Hooked
1980 P125X, 1978 P200 in pieces, 93 150 Exclusive (RIP)
Joined: 16 Feb 2013
Posts: 136
Location: New Mexico
Fri Oct 14, 2016 6:53 am quote
I've been researching options to repair a hashed rotary pad on a P200, and it seems that finding someone to repair the pad itself is quickly becoming not an option, and new engine cases are more than I have to spend.

A couple of folks have pointed me to a reed valve solution from SIP: http://www.sip-scootershop.com/en/products/intake+manifold+drt+_40311600

Sounds good to me, but this is my first rebuild, and I am wondering how "bolt on" it really is, how extensive any modification to the engine case might be, etc... I've searched the forum and found some reed valve install threads, but they look more like performance oriented upgrades than the 'rotary replacement, but keeping it stock' type of reason I'm doing it.

If anyone has installed one of these, I would be very appreciative of any information and advice about it. Thanks!
Member
Smallframes!
Joined: 15 Apr 2015
Posts: 24
Location: Palm Beach, FL
Fri Oct 14, 2016 3:56 pm quote
J-B
I have heard of people using JB Weld if the damage is not extensive. Not the best option for sure. Just throwing it out there.
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: 8022
Location: Victoria, Australia
Fri Oct 14, 2016 3:59 pm quote
A friend of mine fitted one. It lifts the carb 16mm apparently.
Hooked
1980 Vespa P200E
Joined: 18 Jan 2016
Posts: 199
Location: Tampa, FL
Fri Oct 14, 2016 5:47 pm quote
To transform a rotary valved engine into a proper reed valved engine is much more than just bolting on parts. The two engine designs have totally different innards for fuel/air flow so to make the transition from rotary valved the engine carters (cases) should be machined out to be like a reed valved engine and should also use a different style crank. Bolting reed valves onto a rotary engine without making the transformation is... well... 2 stroke blasphemy!
Molto Verboso
Lambretta GP200, Vespa P200e
Joined: 10 Jan 2015
Posts: 1182
Location: United States
Sat Oct 15, 2016 12:14 am quote
I wouldnt use that reed valve. Id go for a full proper reed valve and carb. You have to match intake and go with new cranks. Now that Al is apparently not doing scooter stuff not many people to build you a nice crank.
Hooked
1980 P125X, 1978 P200 in pieces, 93 150 Exclusive (RIP)
Joined: 16 Feb 2013
Posts: 136
Location: New Mexico
Sat Oct 15, 2016 8:31 am quote
The pad was previously JB'd and failed, so I'm not going to try that again.

Ginch, is your friend on the forum? If so, perhaps he could shed some light on this install. It sounds like a simple fix on the SIP website, it would be great if it is.

Niz, that was something i was wondering about, what all had to change inside the engine (if anything) to make this work. Does the auto-lube need to be removed?

It is the weekend, SIP is closed. I'll try calling them on Monday and see what I can find out, and report back.

IMG_1561.JPG
Ugh...

Addicted
Vespa Rally 210
Joined: 04 Sep 2011
Posts: 927
Location: uk
Sat Oct 15, 2016 10:49 am quote
I've used the following on a couple of engines now.
Does the trick but you need to open the carb inlet at the top & taper it inwards to get the benefit of the full area of the reeds.
Also need to do a wee bit of fettling with a dremmel where the reed housing meets the casing at the top of the clutch cover - its not a big deal & takes half hour tops.
And a lot cheaper than what SIP offers.
I got 75mph using one on a Rally engine that had no rotary pad, malossi 210, reed crank, sip road pipe & 24 SI carb.
Also did a completely full rebuild of a lads Rally 200 engine last year that had a shot rotary pad & i used one of these reeds. Running fine.

http://www.ebay.co.uk/itm/SI-Vergaser-Membranspacer-fur-Vespa-PX-Sprint-GL-Rally-Cosa-VNB-VBA-Motor-/351743964029?hash=item51e592f37d:m:mfUzEKmpB5Q2ALVzHQrJ_BQ

[/img]

Capture.JPG

Hooked
1980 P125X, 1978 P200 in pieces, 93 150 Exclusive (RIP)
Joined: 16 Feb 2013
Posts: 136
Location: New Mexico
Sat Oct 15, 2016 4:36 pm quote
Hi Nebulae. I was thinking that matching the ports in the case and the carb to the ones in the reed valve would probably be a good idea just to get a smooth air flow. Is this correct? Does fettling mean cutting? =\

Is the modification something like this? Reed Valve to fix rotary pad destruction

You mentioned something about a reed crank, what is that? Is that a modified crank? I'm hoping to get away with just a bit of modification. Replacing the crank and perhaps some other parts would probably be getting close to what I might be able to get the rotary pad fixed for. I'm getting an estimate on Tues. at a local custom motorcycle shop.

Any more information as to the extent of the modifications necessary to do this fix would be greatly appreciated. Can anyone run down exactly what is necessary to do this conversion/fix? It would be very helpful in evaluating difference in cost between the two options. Reed valve conversion and whatever that entails vs rotary pad repair. Again, thanks for the discussion, your collective experience, and answering my questions.
Addicted
Stella 2T, P200, Rally 180 Euro
Joined: 06 Jan 2014
Posts: 578
Location: Camden, ME
Addicted
Vespa Rally 210
Joined: 04 Sep 2011
Posts: 927
Location: uk
Sat Oct 15, 2016 6:58 pm quote
You could go with Keatons mod above with full on reed block & gas guzzling 30mm carb set up.
I opted to use casings that I bought that had no rotary pad & had a modified carb inlet port (when I say opted - I only found out when I bought them).
I was close to selling the casings purely coz I wasn't in the slightly bit interested in fitting a non-si carb.
I found the nice wee reed block that I linked above, fitted it & ran a few miles.
I did a simple bolt on (lazy) but was disappointed with the performance which was my own fault.
I removed & stripped the engine.
I matched the wee reed block by dremelling open the carb inlet more for a better flow.
I then replaced the crankshaft with a reed valve crank.
Standard cranks have webs (discs on one side) that work in unison with the rotary valve & piston to control the fuel mixture inlet to the engine (along with the downward/upward piston movement).
Reed conversions with proper reed cranks omit the rotary pad / crank control & let the piston take full control of the fuel intake along with the reed valve.
I can inderstand folks opinions above by saying a simple reed bolt on is blasphemy for 2 stroke engines - it is blasphemy.
You can't have 2 methods of control for fuel intake.
In classic vespas, its either rotary control or reed control, not a combination of both.
Reed cranks are just that - cranks that don't have their web on the carb side cut to suit the timing of the piston on the down/up stroke.
Reed cranks can have next to no webs at all as its the piston stroke that controls when to draw the fuel thereby "sucking" open the reeds.
And yes, fettling means dremelling.
I hope I've explained it well.
Its 4am here I've had a few ciders & typing on a tiny blackberry screen
I'll have a read again tomorrow
Addicted
Vespa Rally 210
Joined: 04 Sep 2011
Posts: 927
Location: uk
Sat Oct 15, 2016 7:01 pm quote
I'll post a link tomorrow to previous conversions I've done using the reed block I've linlked above.
Hooked
1980 P125X, 1978 P200 in pieces, 93 150 Exclusive (RIP)
Joined: 16 Feb 2013
Posts: 136
Location: New Mexico
Sun Oct 16, 2016 9:24 am quote
Thanks Nebulae any and all help figuring this out is appreciated.

I did some looking at crankshafts and it seems there are two types that work with reed valves, a cut (or flowed) crank and a full circle. Is one more performance oriented than the other? I really don't want a "tuned" bike, just one that is going to get me around town and some rides out in the country with 2-up sometimes. Reliability is important too. Looking forward to seeing your posts...
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: 8022
Location: Victoria, Australia
Sun Oct 16, 2016 1:26 pm quote
I asked my friend for a few words on fitting the DRT reed - hopefully will have something shortly.

Normally the crank has 2 functions, one to keep the piston going up and down (duh!), the other is to close the crankcase via the rotary pad so that the gas can be compressed and find it's way into the cylinder. When you fit a reed, that does the closing bit. So now the crank gets in the way of gas flow from the carb. I'd stay away from full-circle cranks, they are better where your intake is on the cylinder, not on the case. Here are a few flowed reed cranks - http://www.sip-scootershop.com/main/base/Results.aspx?t=flowed+reed+crankshaft&d=(px)&a=1&sort=0

But my choice would be this one -


The shape helps to balance it and also to keep blocking of gas flow from the carb to a minimum. The flowed cranks do this by reducing the clutch side web of the crank to keep the opening as big as possible.

http://www.sip-scootershop.com/en/products/bellshaped+crankshaft+mazzu_45041000
Addicted
Vespa Rally 210
Joined: 04 Sep 2011
Posts: 927
Location: uk
Mon Oct 17, 2016 2:41 am quote
Ginch has got it . . .
I remember us both discussing this a while back.
Avoid full circle cranks . . .

Heres some photos of the reed i linked above that i fitted to a lads Rally 200 engine that I re-built for him last year.
You see i've opened the carb inlet to match the reed area better.
In photo 2 you can see where i've had to dremmel a wee bit off the engine casing on the bit sloped at 45 degrees as it prevents the reed block from sitting flush. Where it looks shiny is what I've removed. Photo 5 shows where the reed block meets the casing needing trimmed at the top of the clutch housing.
The crank i fitted was a reed crank but not cut away to the extent as the one that Ginch shows above.
The one i fitted was a Serie Pro i think.

01.jpg

02.jpg

03.jpg

04.jpg

05.jpg

07.jpg

08.jpg

09.jpg

10.jpg



Last edited by nebulae on Mon Oct 17, 2016 2:47 am; edited 1 time in total
Addicted
Vespa Rally 210
Joined: 04 Sep 2011
Posts: 927
Location: uk
Mon Oct 17, 2016 2:43 am quote
Also a facebook vid of the engine running in a test rig.
You can hear its quite responsive.

https://www.facebook.com/davie.blair.7/videos/918107594899525/
Addicted
Stella 2T, P200, Rally 180 Euro
Joined: 06 Jan 2014
Posts: 578
Location: Camden, ME
Mon Oct 17, 2016 3:12 am quote
Personally, I don't think I would go with a stock carb and those reeds. The reed blocks that use wedge style RD400 reeds, are much better in my opinion. Although you do have to go to a normal slide carb.

I bit more expensive going to a completely different carb.
Addicted
Vespa Rally 210
Joined: 04 Sep 2011
Posts: 927
Location: uk
Mon Oct 17, 2016 3:43 am quote
keaton85 wrote:
Personally, I don't think I would go with a stock carb and those reeds. The reed blocks that use wedge style RD400 reeds, are much better in my opinion. Although you do have to go to a normal slide carb.

I bit more expensive going to a completely different carb.
If the OP was looking for a rapid tuned engine then I'd agree with you.
But he's only looking for one that runs by sorting his duff rotary pad.
And in his case a reed crank isn't strictly necessary but a bonus & will offer better response & unhindered top speed.
When I fitted the reed to my engine with no carb port mod & standard crank I still hit 65mph.
After opening the carb inlet & fitting the reed crank I got up to 75mph with a standard 24si carb (+ malossi 210 & SIP road pipe).
Its horses for courses & think the OP is looking for an engine more standard than tuned.

Point to note. I went up to a main jet size of 145 in the 24si carb.
Addicted
Stella 2T, P200, Rally 180 Euro
Joined: 06 Jan 2014
Posts: 578
Location: Camden, ME
Mon Oct 17, 2016 7:30 am quote
That's pretty good!! I've always heard a 24/24 carb on Stella style reeds doesn't work well. I guess I need to try it out on my scoot.

Thanks for the insight, that would definitely be the way to go for the OP. Never have to worry about the rotary pad again.
Hooked
1980 P125X, 1978 P200 in pieces, 93 150 Exclusive (RIP)
Joined: 16 Feb 2013
Posts: 136
Location: New Mexico
Sat Oct 22, 2016 10:48 am quote
Ok, so the local custom motorbike place can't resurface the rotary pad, and the closest place I can send it would charge $250-$300. It looks like I'm going with the reed valve set up.

Thanks to nebulae for the pics and instructions. In a related post I was told that with the reed valve, one cannot have the auto-lube hooked up. I just wanted to check and be sure. I would like to keep the auto-lube if possible...

I looked on the forum and saw a post that said: "You could just put something in the pipe to block it or you could remove the stuff that goes down the motor with pliers while rotating the flywheel back and forth a little. Then get the plug found in assorted scootershops to jam down the hole or make your own plug". I'm thinking that the 'stuff' is the gear that works the autolube, I also saw something about filling the trench that the oil used to go through to prevent air from flowing through it. Is this fairly accurate?
Addicted
Vespa Rally 210
Joined: 04 Sep 2011
Posts: 927
Location: uk
Sat Oct 22, 2016 11:29 am quote
Sounds about right.
Dump the autolube.
Not sure if you need to infill the oil channel but if you do then just use some rubber gasket cement during assembly.
You may need to upsize your main jet by a couple of sizes when going from autolube to pre-mix.
Hooked
1980 P125X, 1978 P200 in pieces, 93 150 Exclusive (RIP)
Joined: 16 Feb 2013
Posts: 136
Location: New Mexico
Sat Oct 22, 2016 11:45 am quote
Ok. For anyone interested, I found this 'tutorial' with photos.

Soft Seize - Want to disconnect Autolube
Enthusiast
'77 VLB, '79 VBC
Joined: 22 Mar 2016
Posts: 93
Location: Bodgeville, South East Asia
Fri Dec 02, 2016 7:53 pm quote
Ginch wrote:
I asked my friend for a few words on fitting the DRT reed - hopefully will have something shortly.

Normally the crank has 2 functions, one to keep the piston going up and down (duh!), the other is to close the crankcase via the rotary pad so that the gas can be compressed and find it's way into the cylinder. When you fit a reed, that does the closing bit. So now the crank gets in the way of gas flow from the carb. I'd stay away from full-circle cranks, they are better where your intake is on the cylinder, not on the case. Here are a few flowed reed cranks - http://www.sip-scootershop.com/main/base/Results.aspx?t=flowed+reed+crankshaft&d=(px)&a=1&sort=0

But my choice would be this one -


The shape helps to balance it and also to keep blocking of gas flow from the carb to a minimum. The flowed cranks do this by reducing the clutch side web of the crank to keep the opening as big as possible.

http://www.sip-scootershop.com/en/products/bellshaped+crankshaft+mazzu_45041000
But if the intake port was largely ported and the rotary pad was removed, using normal crank wouldn't give much a problem isn't it Ginch?
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: 8022
Location: Victoria, Australia
Fri Dec 02, 2016 9:10 pm quote
No, no problem at all. It'll work fine witha standard crank, just not quite as good as a purpose-made reed crankshaft.
Enthusiast
'77 VLB, '79 VBC
Joined: 22 Mar 2016
Posts: 93
Location: Bodgeville, South East Asia
Fri Dec 02, 2016 9:14 pm quote
Ginch wrote:
No, no problem at all. It'll work fine witha standard crank, just not quite as good as a purpose-made reed crankshaft.
Which is a bell shaped crank. Noted. Thank you.
Lurker
P200e
Joined: 02 Feb 2018
Posts: 1
Location: Nelson, NZ
Fri Feb 02, 2018 11:58 pm quote
I have fitted a reed valve manifold (as above) that fits under the si 24/24 carb on a P200e. I opened the inlet as much as possible under the carb box to make the most of the reed and ensured there was a gap between the crank web (standard Mazzuccheli) and the inlet to ensure a full pulse.

Just want to know what jets are being used by others out there with this reed valve manifold? The compression has been increased (2.5mm squish incl. 0.5mm base plate). I have retarded the timing to ~19 (IT mark). Have tried 128 mm with B7ES spark and still running in new piston rings.
Ossessionato
Joined: 26 Oct 2015
Posts: 2801

Sat Feb 03, 2018 7:13 am quote
skipperfax wrote:
I have fitted a reed valve manifold (as above) that fits under the si 24/24 carb on a P200e. I opened the inlet as much as possible under the carb box to make the most of the reed and ensured there was a gap between the crank web (standard Mazzuccheli) and the inlet to ensure a full pulse.

Just want to know what jets are being used by others out there with this reed valve manifold? The compression has been increased (2.5mm squish incl. 0.5mm base plate). I have retarded the timing to ~19 (IT mark). Have tried 128 mm with B7ES spark and still running in new piston rings.
I don't know about the jetting, but that's a very large squish. Have you considered bringing it down closer to 1.5mm? And you say that the compression has increased...do you know what it's currently at?
Member
Vnb 125 large-frame
Joined: 19 Aug 2018
Posts: 12
Location: Belgium
Mon Aug 20, 2018 10:44 pm quote
nebulae wrote:
keaton85 wrote:
Personally, I don't think I would go with a stock carb and those reeds. The reed blocks that use wedge style RD400 reeds, are much better in my opinion. Although you do have to go to a normal slide carb.

I bit more expensive going to a completely different carb.
If the OP was looking for a rapid tuned engine then I'd agree with you.
But he's only looking for one that runs by sorting his duff rotary pad.
And in his case a reed crank isn't strictly necessary but a bonus & will offer better response & unhindered top speed.
When I fitted the reed to my engine with no carb port mod & standard crank I still hit 65mph.
After opening the carb inlet & fitting the reed crank I got up to 75mph with a standard 24si carb (+ malossi 210 & SIP road pipe).
Its horses for courses & think the OP is looking for an engine more standard than tuned.

Point to note. I went up to a main jet size of 145 in the 24si carb.
Sorry tot revive this.
But as i read here. Not looking for performance and a top off 45 tot 50 mph ( max legal speed here) i could use that reed pad as a bolt on mod to a Vespa vnb 125 to? So if don't have any other mods that come with splitting open the blocks?

Grts.
Member
Aprillia Mojito 150, Vespa Gts 250ie, Vespa wide body, Yamaha vino
Joined: 11 Oct 2016
Posts: 23
Location: Maryland
Mon Oct 08, 2018 11:23 am quote
Just a heads up to everyone. I've been trying to order the reed block membrane that nebulae posted about from www.scootermax.DE and found that they are no longer in business. I believe the membrane was made in house so they are not available from anyone else.
Addicted
PX 150
Joined: 15 Sep 2006
Posts: 526
Location: Gold Coast, Australia
Mon Oct 08, 2018 5:48 pm quote
Im running a Malossi reed valve kit.
X360 manifold, 30phbh carb.
Malossi have taken a lot of the guess work out of it and supplied a really nice all in one solution.
Mind you there’s a lot of material to remove from the rotary pad area but it does make a big difference to performance once dialled in

1367FA90-F215-4CFF-8A97-F01F6EEA9B1A.jpeg

Addicted
PX 150
Joined: 15 Sep 2006
Posts: 526
Location: Gold Coast, Australia
Mon Oct 08, 2018 5:49 pm quote
And the reed valve. Very similar in size to an MRP and the like

87BE38DC-EAA1-419E-93DE-79ACB514DBD1.jpeg

Member
Iris 200
Joined: 05 Sep 2020
Posts: 5
Location: Sevilla, Spain
Sat Sep 05, 2020 11:59 pm quote
[/quote]

Point to note. I went up to a main jet size of 145 in the 24si carb.[/quote]

Did you need to change the idle jetting or air screw bolt?

I fit a DRT system and the scooter doesnt runs well at low rpm unless I underscrew 3.5-4 the fuel mixture bolt.

Could you tell me your setup?
Thanks
Molto Verboso
2007 Stella 150
Joined: 02 Nov 2019
Posts: 1290
Location: Rochester, Minnesota
Sun Sep 06, 2020 4:24 am quote
sayonarab wrote:
Point to note. I went up to a main jet size of 145 in the 24si carb.[/quote]

Did you need to change the idle jetting or air screw bolt?

I fit a DRT system and the scooter doesnt runs well at low rpm unless I underscrew 3.5-4 the fuel mixture bolt.

Could you tell me your setup?
Thanks[/quote]

Try one of these threads, not a tuning expert. But from my understanding of you are further out then around 2 turns go to a richer jet.

Have you verified no leaks around the work that you performed?


Calling all tech heads! Si Idle jet question(s)...


Mixture screw adjustment, got a good link?
Member
Iris 200
Joined: 05 Sep 2020
Posts: 5
Location: Sevilla, Spain
Sun Sep 06, 2020 5:28 am quote
Christopher_55934 wrote:
sayonarab wrote:
Point to note. I went up to a main jet size of 145 in the 24si carb.
Did you need to change the idle jetting or air screw bolt?

I fit a DRT system and the scooter doesnt runs well at low rpm unless I underscrew 3.5-4 the fuel mixture bolt.

Could you tell me your setup?
Thanks[/quote]

Try one of these threads, not a tuning expert. But from my understanding of you are further out then around 2 turns go to a richer jet.

Have you verified no leaks around the work that you performed?


Calling all tech heads! Si Idle jet question(s)...


Mixture screw adjustment, got a good link?[/quote]

Dear Christopher,

Yes, I know I need a richer idle jet, i will buy 48/100 , 45/100 to try. No leaks I saw several times and nothing.

Thanks for your links I will read them.
Addicted
63 Lambretta LI 125 series 3, 71 Sprint Veloce , 2005 Vespa PX150, 1979 P200E
Joined: 04 Jul 2011
Posts: 887
Location: Tucson, AZ
Sun Sep 06, 2020 8:23 am quote
I had a bizarre mechanical breakdown years ago. Some how my middle screw cae loose and the spring got sucked into the reed. The P200E loss power but it was still rideable. I ended up putting a hyper strong bond for mining drilling bits, it took 24 hours to cure and all of that but it has been working great for years now, I have strong compression.

Your other option is to weld aluminum and bring it back down to the original shape. At one point I put a set of slightly damage engine cases with slightly grooved reeds and they took it of my hands. Good luck.
Member
Iris 200
Joined: 05 Sep 2020
Posts: 5
Location: Sevilla, Spain
Sun Sep 06, 2020 9:53 am quote
scooterist wrote:
I had a bizarre mechanical breakdown years ago. Some how my middle screw cae loose and the spring got sucked into the reed. The P200E loss power but it was still rideable. I ended up putting a hyper strong bond for mining drilling bits, it took 24 hours to cure and all of that but it has been working great for years now, I have strong compression.

Your other option is to weld aluminum and bring it back down to the original shape. At one point I put a set of slightly damage engine cases with slightly grooved reeds and they took it of my hands. Good luck.
Dear Scooterist.

I have a nbew engine with DRT valve fitted and all the cases ported with it and Malossi 210. You can reed it on my post.

I asked because all the carburation setup has changed when i fitted the valve.

Reed Valve jeting problems

Anyway many thanks for your support.
Scooting the Ozarks is a scooter rally held in Eureka Springs, Arkansas offering riders scenic twisty rides, poker run, and more.   vespa scooterwest scooter west Motorsport Scooters   Scooter Parts Company
Post Reply    Forum -> Not-So-Modern
[ Time: 0.1735s ][ Queries: 27 (0.0364s) ][ Debug on ]