Jetting Help?

[bubbag]

Hello,
I have a .50 over fresh top end, unported cylinder w/ wiseco pro lite piston, with new boyeson reeds, stock air box w/snorkel, w/K&N filter w/ lid on, the engine shows 150psi on a compression test.
Also FMF fatty exhaust system (it leaks at spots, @ cylinder head and where the muffler joins to the pipe).
I have a Eddy sanders racing 1 yr old 38mm keihin airstryker.
And I'm mixing 40:1 w/ Belray HR1 synthetic premix, w/91 octane.
I live at about exactly 3000ft elevation and weigh about 205lbs.

What would be a rough guess on my jetting as rite now I had ESR send me a new pilot jet and needle jet to try and richen the bike up on the low end, and it does seem to run rich and bogs from idle to 1/4 throttle. Then from there up the bike runs lean and doesn't seem to have a smooth hit in power.
The needle is in the bottomest position and the main jet is a 205 which seems big to me :( (how big does keihin make main jets)
I have a ESR airbox eliminator kit and the big seems to run lean at all throttle points when it is used, does anyone else have problems like this when living at a higher elevation?
I have the eliminator kit off and hoped using the stock airbox would help matters but it just seems to make the bike bog more?\

Thanks
Byron

[zedicus00]

it sounds like yur initial problem is an airleek in the system sumwhere. exhaust side doesnt matter too much on that though.

considering how different every setup is an the mithical arts behind jetting, my advice is to read this, its jetting in laymans terms.

http://www.maximausa.com/technical/lubenews/springsummer2001.pdf

o and i dont like yur choice in premix. run castor 927, or goldenspectro, or klotz. belray makes good gear oil but there premix will gum up the crank after a while.

[bubbag]

Thanks for the help bro, appreciate the help u are always giving me.
I'm gonna have a talk with the boys at ESR tommorow and try and get some more bigger jets and maybe a diff needle/pilot jet?
Anyway I think I'm gonna pick up a new cr250 tommorow to fill in all the time the R is broke :devil:

[bubbag]

I talked to the guys at ESR and they said that it is probably my ignition and it is failing, so I ordered a flywheel puller and I'm gonna pull the flywheel and see if it is wore out.
If it is I will be ordering the complete CR ignition from ESR, what are everyone's thoughts on the ignition?

[zedicus00]

also i just noticed u said yur engine shows 150lbs compression, thas a lil low even if it were a stock engine. as for the ignition, i hear peeple having problems with the stock ignition but ive never had any problems with the stock ones. as long as its kept dry an clean it should be o.k. you may want to check the coil and cdi. the stock coils arent the best, and cdi's do whare out. but my main concern is yur compression, especially if that is a new rebuild.

[Dave83]

Check the ignition with an ohm meter.You will not have to pull the flywheel to do that.If I had my manual handy Id give you the ohm specs,but its loaned out.The 205 jet is huge especially with the airbox and lid.

[bubbag]

Well it could be the gauge I'm using to do the compression tests it is a cheapo unit so I hope for my sake that is why that isssue is. :confused:

I have a manual too but I asked the guys at esr if there was anyway to test that **** and he said "no" so I guess I will go read the manual and see if I can't figure out whats up.

[Dave83]

If you are talking about testing the ignition,there is a whole page of specs for ohming the system in the Clymer manual.

[jcas]

Try running some higher octane gas. Get that 91 out of your tank and put some 110 or higher. My bike was doing the same thing so I replaced the cdi box, stator, wiring, and crank seals. I took the motor apart twice and put all new gaskets in to make sure there wasn't an air leak. Changed the reed cage and intake boot in case there was a leak there somehow. On a 265 cylinder with a 34 pj carb I was jetted on the main up to 210 and the bike still wouldn't bog. I thought maybe the fuel petcock was clogged so I emptied out the tank and cleaned it, even though there was plenty of flow out of the line. When I filled it, I used some 110 I had and then the bike started to bog. Now, the setup is: ESR 310, cool head with high comp. dome, trx5 pipe, ESR air box eliminator kit, boyeson c/f reeds w/ CR reed cage/boot, and 38mm A/S carb. The carb is jetted with 50 pilot, needle at the bottom position, and a 185 main that's still a little rich. Good luck finding the problem, it's a b$tch.
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