2001 Polini X-1 Low Compression

[theroyz71]

I've got a 2001 Polini X-1 Works that has lost some low end power an compression. We got the bike in February and it ran like a scalded dog. Now, it seems to run fine but it doesn't jump off the line like it used to. I ran a compression test and only got about 90 psi so I put in a new piston (C) and ring in the (B) cylinder. I gapped the ring end to approximately .008 which is within the .004-.012 range shown in the manual. I put everything back together and the compression is still the same. I also replaced the reeds and it made no difference.

What else could it be? Do I need a tighter ring end gap? I thought about crank seals but the bike seems to idle fine.

 

[Jasle]

is this after you broke the rings in or before? The rings could need some time to seat. do two heat cycles. You can also drop a teaspoon of oil down the plug hole and then check compression again. If it jumps dramatically then you are leaking by the rings. You cylinder could be out of round and in need of honing or recoating?

 

[theroyz71]

Thanks Jason. I knew you would reply to this topic. I did heat cycle the motor and we ran two practices and two race motos on it and the compression was still low. I did not mic the cylinder but it looks all right with the ring in it.

I actually got tired of screwing with it and bought a 2004 CM50. Wow, what a rocket. I'm gonna try putting the Polini together one more time, checking everything out before final assembly. If it's right, I'll sell the whole bike. If not, I'll probably part it out. I need to get some money so I can get a PW3 for the Oil Injected Class.

 

[Jasle]

Oh man just when I was about to become a Polini dealer and now you've switched...Whats the world coming to. Not much touches the CM in the 4-6 class. Different story the bikes are much closer in the SR.
I have seen low compression when the crank seal had popped out. but then the bike didn't run...
maybe coming off the line is caused by some clutch issues, jetting or a possible air leak? thats in the order I'd suspect them too.

 

[theroyz71]

Polini Dealer? Good for you, they're great bikes and I really struggled with the switch. I haven't looked at our Polini since we got the Cobra.

I called your store today looking for a PW3. I talked to a woman but didn't get her name.

 

[Jasle]

That would have been kelley. We don't keep P3's in stock since we don't have an oil injected class around here. Only two pw-3's in the state of AZ right now. Anything with Cobra or KTM all gets dropped inthe same class. Only PW50 and jr50, xr50 get their own class.
I can drop ship them if you need a new one. I am only in the shop Mon-Wed 8-4 and 2p-4p thurs and fri...

 

[theroyz71]

I got one this weekend in South Carolina. Bought it from a KTM Talker that we know. It's an 04 but it has the updated swingarm. It's been well cared for and has recently had the forks done and the shock serviced. I even got an extra clutch.

 

[rockcrawlerdude]

I got one this weekend in South Carolina. Bought it from a KTM Talker that we know. It's an 04 but it has the updated swingarm. It's been well cared for and has recently had the forks done and the shock serviced. I even got an extra clutch.

man i cant get away form you can i :moon: .....LOL J/K hows everything going? good i hope... if we dont sell kalis x-1 soon then we're just gonna have to put x-3 suspension on it becuz its too much $$ to get an X-3...see ya on da boards....nathan

 

[theroyz71]

Dude, are you stalking me. :nener:

Is the frame on the X-1 and X-3 the same? I'd make sure the steering head angle is the same first.

Have you got that girl racing yet?