P200 Holed Piston Recovery

Need help? Want to help? Discuss technical issues and share tips.
User avatar
Mikeh
Posts: 873
Joined: Wed Oct 04, 2006 2:36 pm

Re: P200 Holed Piston Recovery

Postby Mikeh » Tue May 22, 2012 4:34 pm

The big end bearing can only be removed by pressing the crank apart. The only reliable person I know to trust to do this is Hot Rod Al.

As far as longstroke is concerned, the stock cylinder and piston will work fine with a longstroke crank You need to use a base gasket and have the cylinder head modified. Hot Rod Al could do that work for you while he is boring the cylinder out. He would likely also massage the ports to open the timing a little more to allow for the piston travel.

On timing, the marks are there for a starting point. You need to set your timing close to stock which I beleive is between 21 and 23 degrees BTDC. From memory of what I saw in the photo it looked like your timing was advanced.

Advanced timing is great for short racing but will make your motor run hotter than it should. You always want to run as advanced as you can without melting your piston. Obviously you went a little too far.

I once has a malossi 210 motor in a VBB that when the timing was set to 18 DBTDC and the jetting was under a 112 jet it was crazy fun to ride at rallies and around town. But I had to nurse it when going on long rides or I'd seize up. If I knew I was going on a long ride I would rejet and retime the motor and it would be fine.. just slower off the line and the top end speed was about the same.

If you keep the motor stock, just set the timing to stock settings and leave it alone. Use a timing gun with a dial adjustment to see where the motor is really firing when the motor is running. And check to see if the marks move around when the engine is revved up. This would indicate a bad pick up.

If you tune the motor with a pipe, longstroke crank or weird non-stock jetting then I suggest you start with a stock setting on the timing and borrow an exhaust gas sensor and install it on your scoot temporarily for tuning it. Then run the scooter on the freeway for about 5 to 10 miles at wide open throttle and see how hot the exhaust gas gets. Depending upon where you mount the sensor in your exhaust you should get temps in the 1100 to 1350 range and NO higher. If you motor ever goes higher than 1350 then you need to retime and/or rejet the motor to make it run cooler.

For pictures of pullers look at this thread;
viewtopic.php?f=4&t=4124

You can see what I made.

Ramsay has the pullers right now but I should get them back in a day or two. I'm way up in ellicott city. You are welcome to borrow them but I don't know when I'll see you or if you want to come up to get them and drop them off when you're done. Perhaps someone at modern classics can loan one out to you or you can just take the motor there to pop the crank out. Also if you're going to replace the crank or big end bearing then the crank balance should not be an issue so it may be ok to just whack it out of there with a pipe. When installing the crank, if you freeze the crank and heat the bearing/seal with heat gun a little you may get lucky and the crank can slip right into place.. sometime a little extra pull is needed though, you can get by with pulling the crank in place using the clutch (or pile of big washers) as a big bushing and the clutch nut will pull the crank into place as you tighten it; Just do it with no washers or woodruff to pull the crank in.. then take the clutch (or pile of washers) out and assemble the case halves.

Good luck

dirtyhandslopez
Posts: 876
Joined: Thu May 01, 2008 1:12 am
Location: Richmond, VA.

Re: P200 Holed Piston Recovery

Postby dirtyhandslopez » Thu May 24, 2012 10:52 am

No wonder it popped that piston, timing is/was way advanced. I'd guestimate and say you were running 27-8 degrees of advance with the stator set in the position shown. I am very surprised you made it as far as you did.
At 20-1 degrees, the mark on the stator will be roughly touching the mark on the case but to the left of the mark on the case. Roughly. I set up with a dial guage indicator and a timing disc.
That's not going anywhere

hurleybt
Posts: 406
Joined: Sun May 25, 2008 10:45 pm

Re: P200 Holed Piston Recovery

Postby hurleybt » Thu May 24, 2012 12:29 pm

So is there any system Vespatronic, Parmakit, etc, that will let you easily adjust between two different timings like Mike did? One for in town quick short power and another for long sustained high speed riding?

Or is that the grail Mike has been searching for?

User avatar
Mikeh
Posts: 873
Joined: Wed Oct 04, 2006 2:36 pm

Re: P200 Holed Piston Recovery

Postby Mikeh » Thu May 24, 2012 1:01 pm

There is nothing that allows a switch like that available off the shelf for vespa scooters.

The closest you can get is the SIP offered AddOnV adapter for the CDI which gives an ignition curve that is adjustable with a screw. I suppose you could buy two of them and connect them both but have a double throw switch to use one or the other.

I have been researching modern chinese scooter iginition components and some claim to have switches on them to alter the curve.. I may buy one to play with. There are a few threads on stella speed about that.

And yah what Darren said has me rethinking the 18 dbtdc that i posted earlier about.. I'm a little foggy/unsure of what timings i used for making a wheelie machine.. but come to think of it I must have been jetting hot and advancing to 23 degrees or slightly more.. and then for road trips making the jetting rich and setting the timing between 18 and 21. Senior moments seem to happen more frequently these days...

When you start messing with jetting and timing on a modified motor you have to just feel it all out and listen to what people tell you and keep it in your mind.. but every motor and tuner is different and we all tweak things differently.

dirtyhandslopez
Posts: 876
Joined: Thu May 01, 2008 1:12 am
Location: Richmond, VA.

Re: P200 Holed Piston Recovery

Postby dirtyhandslopez » Thu May 24, 2012 2:05 pm

As a side note, make sure you are running these puppies on the highest octane you can get, hopefully 93. The ethanol makes em run hot as it is...
That's not going anywhere

User avatar
Zeets
Posts: 905
Joined: Thu Aug 19, 2010 6:42 pm
Location: Kensington (for now)

Re: P200 Holed Piston Recovery

Postby Zeets » Thu May 24, 2012 5:26 pm

There was a thred I read somewhere about 50cc guys in Scandinavia that build bikes that have a map switch that changes the ignition. I guess the cops there pull them over and make them run on portable dynos. Over a certain HP, they're required tags.

I know KTM dirtbikes have a switch on the handlebar that changes the igniton map too.

Since they're all singles, I'd assume the technology used on one would be adaptable to another. It'd be my guess that there would be aftermarket setups available that are pretty universal. RD Chinoy makes a system that works for the RD with switchable, mappable ignition curves as well.
Zayretow

70' Vespa Sprint (2009 LML power)
74' Yamaha RD350 (pinger)
2008 Suzuki DRZ-400SM (thumper)

User avatar
toigo
Posts: 198
Joined: Sun May 01, 2011 8:47 pm
Location: Mt Pleasant
Contact:

Re: P200 Holed Piston Recovery

Postby toigo » Thu May 24, 2012 9:20 pm

So back to the subject at hand although easily variable ignition timing does sound awesome. If I lived in a country where taxes went to equipping police with mobile dynos I'd be pissed, or either befriend a cop while I was tuning my bike.

I bought a drift and popped out the input shaft and output shaft. Put a new cruciform in the gear cluster for the output shaft and checked the clearance at the thrust washer. Also popped out the right side bearing and seal. I realized I lent my clutch nut tool to someone on the cannonball and never got it back so I'll have a new one early next week to finish up. Two quick questions.

Installing the right side crank shaft bearing and seal... I'm assuming I just rig up some sort of setup with a bolt, some nuts, and washers and then tighten it to force the bearing into the case or is there some other way? Same thing for the seal too?

The spots on the sides of my crank. It looks like small bits of rust almost. Is this anything to care about? Should I smooth it out or try to sand them off? Wouldn't want to mess up the clearance by doing anything to the crank I think. Where the rotary pad is making contact looks fine and that's the most important correct? Crank photo below.

Image

User avatar
Zeets
Posts: 905
Joined: Thu Aug 19, 2010 6:42 pm
Location: Kensington (for now)

Re: P200 Holed Piston Recovery

Postby Zeets » Fri May 25, 2012 8:37 am

Green or brown scotchbrite will take care of that minor surface rust without doing any damage to the crank or removing any material. Shoot a little WD40 on it as a cleaner and scrub away. Also, if you're down to bare cases, some Gum Cutter (available at any autoparts store) will blast away all of that gunk that is discoloring the interior of the case.

http://www.berkebileoil.com/special.htm

I could sniff Gum Cutter for days. (and have)
Zayretow

70' Vespa Sprint (2009 LML power)
74' Yamaha RD350 (pinger)
2008 Suzuki DRZ-400SM (thumper)

User avatar
Zeets
Posts: 905
Joined: Thu Aug 19, 2010 6:42 pm
Location: Kensington (for now)

Re: P200 Holed Piston Recovery

Postby Zeets » Fri May 25, 2012 8:53 am

Back to the real concern at hand...

It appears that MSD makes a customizable CDI for 1 cyl 2 and 4 stroke engines... It's mappable and switchable. (It's $324 too, but probably worth it to someone building a high dollar scoot motor)

http://www.summitracing.com/parts/MSD-4217/
Zayretow

70' Vespa Sprint (2009 LML power)
74' Yamaha RD350 (pinger)
2008 Suzuki DRZ-400SM (thumper)

User avatar
porter
Posts: 349
Joined: Wed Mar 12, 2008 4:12 pm
Location: lutherville, md

Re: P200 Holed Piston Recovery

Postby porter » Sat May 26, 2012 8:48 pm

I have a parmakit variable ignition made for p200s. I haven't given much run time but I will say that it's low down torque is a nice match to a normally revvy pipe setup. It's a quality kit with its own stator plate, flywheel and hardware. I believe the specifics are 7 degrees of timing shift. Mine is set for 23 to 15. And 90 watts is awesome.

User avatar
toigo
Posts: 198
Joined: Sun May 01, 2011 8:47 pm
Location: Mt Pleasant
Contact:

Re: P200 Holed Piston Recovery

Postby toigo » Tue May 29, 2012 11:07 pm

Got the crank out and I'm glad I did. There were little bits of piston over on the clutch side seal, and on some of the faces of the crank, but luckily the seal kept them out of the bearing. It doesn't sound like the big end bearing has got anything slowing it up either. I've got everything apart at this point and am going to start putting it all back together.

All said and done, it's looking like left side seal, right side seal, right side bearing, hub seal just cause, small end bearing, cruciform, new 1st over piston, and a slightly bored out cylinder. Got a gasket kit for everything replaceable too.

Anything else worth replacing while I've got the cases split? The hub bearing seems fine and I also rebuilt the clutch recently with new cork plates and springs (got a new clutch washer for reassembly). I can get my hands on a CDI for cheap which I may do because the wires coming off of mine are ratty where they connect to the box. I was going to just slather some 2 part epoxy on where they connect to insulate them.

Some of the wires coming from the left side of the bike to the junction box are also worn through their housing so I'll have to deal with that as well after everything is back together.

Image

User avatar
Zeets
Posts: 905
Joined: Thu Aug 19, 2010 6:42 pm
Location: Kensington (for now)

Re: P200 Holed Piston Recovery

Postby Zeets » Wed May 30, 2012 12:07 am

You can always cover old wires in heat shrink.
Zayretow

70' Vespa Sprint (2009 LML power)
74' Yamaha RD350 (pinger)
2008 Suzuki DRZ-400SM (thumper)

dirtyhandslopez
Posts: 876
Joined: Thu May 01, 2008 1:12 am
Location: Richmond, VA.

Re: P200 Holed Piston Recovery

Postby dirtyhandslopez » Wed May 30, 2012 9:01 am

The old rotten wires on a P stator trick eh?
Happens to most of them eventually. Get that puppy rewired. If your not soldering, wiring friendly, I can do it.
That's not going anywhere

User avatar
Mikeh
Posts: 873
Joined: Wed Oct 04, 2006 2:36 pm

Re: P200 Holed Piston Recovery

Postby Mikeh » Thu May 31, 2012 5:15 pm

Yup most stators need to be rewired if they have not been done since the scooter was new in the late 70's.

The 81 and newer harneses may have a few years left. But the older ones are usually shot. If you solder it yourself then make sure you use a good iron that heats up good and hot. Also use alligator clips as heat sinks so that you don't send too much heat back into the stator wiring or melt the insulation off the wires. You'll want to use tiny rosin filled solder and put an additional dab of rosin on the wires prior to soldering them.

For the terminal end you'll want to use a nice crimper and terminals with no insulators on them. But slip two layers of heat shrink tubing over the wire before crimping.. then slide the heat shrink back over the connector and shrink one tight to the wire and another over the wire and terminal to insulate it. This will give you a professional type result that will be very durable and keep the bare wire from being stressed as it enters the terminal. i like to use double wall heat shrink.. it's thicker and more durable.

And that crank needs a new big end bearing.. so don't bother cleaning it.. send it to Hot Rod Al and have him service it.. or replace it.

User avatar
Zeets
Posts: 905
Joined: Thu Aug 19, 2010 6:42 pm
Location: Kensington (for now)

Re: P200 Holed Piston Recovery

Postby Zeets » Thu May 31, 2012 10:49 pm

I've found that old corroded wires that are hard to solder need a little help. Cleaning the wires with rosin should work, but if you still can't get good solder flow, try pre-cleaning the wires with Gum Cutter. I know, it sounds weird, but it really works. The gum cutter will get the white corrosion off of the wires and help to make solder flow nicely.
Zayretow

70' Vespa Sprint (2009 LML power)
74' Yamaha RD350 (pinger)
2008 Suzuki DRZ-400SM (thumper)


Return to “Service Center”

Who is online

Users browsing this forum: No registered users and 1 guest