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How far out do the valves need to be before they need to be adj?

My CRF wont start, The exhaust valves are at .013 each
Intakes are at .005 and .007.

Could one or two thou out make the difference?

I am waiting for a shim kit.


I have rebuilt the carb, and starter clutch, I have decent spark. I can only get it to backfire and it seems after I have almost killed the battery each time the exhaust pipe at the engine is burning up.
It wont even fire with starting fluid.

Any help is appreciated!

All but one of your valves are out of spec. I personally would adjust all of your valves to spec first and then troubleshoot your problem. We can speculate forever about if your current clearances will affect your starting but the best thing is actually adjust them to spec and then troubleshoot.

Codeman00 wrote:All but one of your valves are out of spec. I personally would adjust all of your valves to spec first and then troubleshoot your problem. We can speculate forever about if your current clearances will affect your starting but the best thing is actually adjust them to spec and then troubleshoot.

Thanks, I will adjust them as soon as I get the kit and go from there..

i agree with cody...get the valves right and then let us know how things go and we can troubleshoot from there. when was the last time the bike started? did it run well then?

ken

I am going buck the trend those valves are not causing your problem. Get them adjusted but keep looking for the cause of your lean condition.

Seams you may have covered most;

Hot start sucking air

Plugged pilot circuit - clean/replace pilot jet

Carb insulator sealed

And my new favorite......needle clip failure. After days of fighting a very similar condition that is what I found. I had the carb in my hands three times before I pulled the top off

Good luck!

yeah, may not be the valves but it's a process of elimination when there are starting issues. best to eliminate the valves and then do as redrooster mentioned and start eliminating other possibilities.

ken

Thanks to everyone for your input...
Will put the valves into spec when shims arrive.
Bought the bike in Nov 2010, huge hour rental bike. Started when I bought it and rode it twice, electric starter was toast, kickstart only. New brushes for the starter, all good, starter clutch was gone, replaced it and the gear, all good. Ive had the carb off 3 or 4 times, cleaned and checked everything I could think of. Got it going once after jumping it from an F350 and some crazy throttle inputs, almost cooked the starter. The bikes at sea level, the box has been opened and I will post the jetting.....


I just wanna ride!!!!!

www.yoloracing.com

sure spec up the valves if you can and if it still wont go its the carby for sure if your not able to take it apart and then rebuild, take it to a carb shop. you have had it apart now it s not going so go over it again get the jetting to spec or for your mods 165 main and clip third from the top fuel screw about one and a half to two turns out make sure you have no air leaks check the air box to carb connections your hot start ect i mean if your carbs been out and now your header glows sounds like to much air to me any way let us know what happens so we can all gain from your misfortune.

Well after 8 months and the birth of my twin boys I finally had the time to figured this thing out. STUCK RING! NO COMPRESSION!. So after a new piston, rings, valves, we are up and running. Carb was fine the whole time. Oh well, we are packed up and off to San Felipe to prerun in prep for the Baja 250 next week. Check us out www.yoloracing.com!