Need some tuning help

[pcemkr]

I have an 87 250R with an 88 bottom end, it has a CR 265 cyl. from Duncan and a bottom to mid Paul Turner pipe, no lid on the air box K&N filter and a 38 mm. Kehan, the PV is blocked off in the cyl. and I have a 55 pilot,183 main and a DGH needle clipprd in the 3rd ring. The bike starts first or second kick, idles good, but is falling all over its self until 1/2 throttle then it tries to take flight. Any suggestions

Also I started the bike for the first time today, went through a couple heat cycles and then road it around the yard, parked it and came back later to ride it again and I had no clutch, like someone had cut the cable, tried to adjust it and with the cable adjusted all the way out, I could barely start to feel clutch at the grip, Any ideas

Thanks guys

[papatrx]

I have a similiar set up. The CR cylinders are set up with very large transfer and exhaust ports from honda and will absolutely rip on the top end. The power valve helps on the bottom end for the mx track. With the power valve blocked off, you will have only top end power. My bike is used for dunes only and that combination is great, but for mx or woods it is going to hurt.

It probably feels like it's only on or off, but that's what happens when you open up the air flow with no power valve to restrict the exhaust flow.

[baker250r]

or try gettin smaller pilot jets... try around 48 and see wut happens. I got the same setup as you... without the cr topend.. I just got a 250r top end thats 265 and all duncan.

sounds like its runnin rich on bottom end...... try doin plug chops and go from there

[JTRtrx250r]

sounds like a jetting deal,

but the clutch..., that sounds weird, how was it when you were riding it? I'd say check the oil level but that wouldnt make it feel like that, the adjuster should be in(on the perch) w/ about 5mm's of free-play. Is it the lower adjustment thats all the way out? maybe an old stretched cable? my heads not workin' w/ me at the moment so sorry about asking questions when your lookin' for an answer

[machwon]

ditto on the lower pilot jet. I typicaly run a 48 in the winter, 42 in the summer.

[pcemkr]

Thanks fellows, I'll give the jetting a try

[pcemkr]

JTR, the adjustment at the bottom is about normal and the one at the perch is all the way out, something must have disappeared inside because the clutch was great for about 15 min., now you can rotate the lever on the engine by hand.

One day I will get to ride this bike:(

[pcemkr]

Thanks for the input fellas, somebody forgot to bend the tabs on the nut that holds the basket on, pull the clutch, move the whole basket. Anyway, fixxed and now working on the jets