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preshure testing 07 250R ?

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Is 10 lbs and 10 min the  no more than 10 % loss the formula?

I,m fooling with a 07R  the cam chain was jumping so its now got a new chain and tensioner the intakes are at 006 and 005 exhausts at 010. The carb has been gone through acc pump kit update passages cleaned new 42 pilot 175 main 50 leek 3rd clip pos fuel screw tuned and likes it at 1 3/4 turns throttle plate seal hot start serviced and have free play.

this bike seems to have a lot of compression and runs very strong but what a bitch to start some times.10 or 20 kicks hot or cold is not uncommon occasionaly it starts in a couple kicks when cold but that's rare, warm starting goes a lot better but not allways great bump starting is not likely a first shot deal when cold. Some kicks the bike fires or pops when kicking butdont catch and run

Im trying to narrow this down I,ve got a big blue spark and cant make the bike stumble or die when wiggling  the kill switch , the timing is bang on and I've serviced many fcr carbs pipe joints are sealed, intake trac is sealed.

Now correct me if I'm wrong but if the intake valves are shot it probably would not be starting in a couple kicks when cold ever ?some times? I'm 6,2" over 200 lbs and know I'm kicking it good I messed with leaning the bike over before kicking it and turning off fuel before shutting it down- it just don't start well cold- should I mess with the comp relese pin modd? in my heart I know it's valves but I wouldn't think I could kick start it when cold if that's the case.

when the cam chain  skiped twice it let the cam rotate one tooth aunti clock weise both times is that enough to bend valves?

would a high comp piston require less plug gap?

its a used bike to me and and ANY HELP APRECIATED  thanks

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the decompression mod was more so needed on the 08 crf250. I had an 07, stock and after a while full modified. In both cases it started easily.Double and triple check clearance and set it to the specs in the manual, not what anyone else says is better than stock specs.

 

My next guess would be wrong size pilot jett and incorrect fuel screw adjustment. having that screw set incorrectly will make starting one hell of an ordeal

 

http://www.thumperfaq.com/fuel_screw.htm

Edited by adam8781

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adam  I know about setting the fuel screw and I have a new extended r&d one in their, new o-ring and all

Today I knocked out the porcelain from a spark plug then welded a tube onto it and threaded it into the plug hole removed the cam and blew air into the tube. The result was I could hear the carb slide rattling and no air coming out the exhaust, because of this I have determined that at least one intake valve is not sealing so the head will be taken off. I know intake valves are prone to failing in these bikes but at least I determined if the head needed attention or not besides shimming.

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