PW80 questions - cylinder boring (are they plated?) & Wiring diagram

[bwiencek]

I purchased a "new to me" mid 90's PW80 for the girls to ride this weekend, it seems a little "weak" to me and I know from the owner that it was a one family bike and little maintenance was done on it other than add oil and gas... I was going to throw a new piston kit in there since it's cheap enough, but if it needs bored can I just have it bored or are the cylinders nikasil / chrome plated and will need to be re-plated?

Anyone know the engine code for this little engine (for chineese parts knock-offs)??

Which gets me to the second thing - anyone got a wiring diagram for this little bike? I know it's got a rev limiter built into the CDI but was thinking instead of buying an early 80's one I may be able to retrofit the 2-stroke "racing" CDI from a chineese scooter that doesn't have the rev limiter in it and then change to a little lower gearing to take advantage of the extended revs...

One last one - has anyone done a "seat lift" - I know in about a year I'll need to do that since the younger one fits well on the bike and the oldest could probably move up to something else next year once she gets more comfortable....

[JAMRACING21]

the pw80 can be bored up no problem there.

i dont know the engine code but the chinese knock off was a PY80 and they made a PZ80. but not all internal motor parts interchange.

i have never done or seen a seat lift for a pw80, but if you want a taller seat by adding foam i can tell you how to do that.

as far as the rev limiter goes i think but dont hold me to it all you have to do is unplug one wire.

i dont have a wiring diagram but this is as close as i could find

bikebandit.com/houseofmotorcycles/yamaha-motorcycle-pw80n-1985/o/m7446

[bwiencek]

Thanks for the reply... I was hoping the cylinders weren't plated - I'm thinking about just ordering a wiseco .5mm over piston and parts before I take it apart and just completely go through it this winter...

I'll have to search around - if it's as simple as unplugging a wire then that's a much simpler solution than I was thinking!

[JAMRACING21]

Thanks for the reply... I was hoping the cylinders weren't plated - I'm thinking about just ordering a wiseco .5mm over piston and parts before I take it apart and just completely go through it this winter...

I'll have to search around - if it's as simple as unplugging a wire then that's a much simpler solution than I was thinking!

there was a kid racing here last year on his pw80 and doing very well on it i asked his dad how he got it to keep up with the klx110's and he said all he did was just unplug the rev limiter and thats it, i believe he told me it was just one wire he had to unplug, yeah i like wiseco pistons they work great and .5 would be a great size to go to if possible i would still go .25 as the .5 doesnt really ad any more power but does shorten the life span of that cylinder. you have to put a www. in front of that link i provided to see that very limited parts fiagram, as far as the seat lift what were you refering to?

[bwiencek]

there was a kid racing here last year on his pw80 and doing very well on it i asked his dad how he got it to keep up with the klx110's and he said all he did was just unplug the rev limiter and thats it, i believe he told me it was just one wire he had to unplug, yeah i like wiseco pistons they work great and .5 would be a great size to go to if possible i would still go .25 as the .5 doesnt really ad any more power but does shorten the life span of that cylinder. you have to put a www. in front of that link i provided to see that very limited parts fiagram, as far as the seat lift what were you refering to?

I looked at the parts diagram - I've got a PDF of all those diagrams but they don't have a wiring diagram - I'm pretty sure they're just ment for getting parts ordered and not diagnostics...

I'll see what the oversizes are .25mm is only about .010" over - I've never worked on something this small but I was worried if the cylinder is out of round or tapered that the .25mm wouldn't be enough to clean it up...

I think I'll try unplugging one wire at a time from the CDI and seeing what happens - e.g. if the kill switch still works and if the bike even runs... if it runs and the kill switch works then I'd have to think that wire was the rev-limiter - probably won't try to find out if that's the case until it's jetted and 'uncorked' to actually take advantage of the extra RPM's...

[JAMRACING21]

did you look at pwonly.com they have the schematics for the pw80 and the show the electrical and generator etc diagrams

[J Scumaci personal]

Pw80 has no rev limiter although it does have restrictions in the exhaust I’ve seen pw80s rev up to 13k on a stand unrestricted with a few other mods