rebuilt motor wont fire ??!!

[quadgod440ex]

This isnt for a honda but i know u guys could help me out . Me and a buddy just rebuilt his warrior , 10.25 comp piston , and rings . You know the normal rebuild . nothing special no high performance valves or cams or anything , just stock bore piston . Well we got it all together , timing marks are perfect , valves are adjusted perfect , were getting spark , and fuel . but she just wont fire . when i hold my hand over the exhaust it doesnt even feel like there is compression . Never had this problem on a rebuild before . Could the rings not be seating right or something ? i know i put them on the piston right . what else could cause this to happen ? Has anyone else had a hard time ever starting a rebuilt motor ? Im deffinatly not gonna try starting fluid on a brand new motor so that is out of the question . Any help is greatly appreciated. Thanks EXriders .

PS I told him to buy a honda!

[westhall55]

i would try a hotter plug and see what you get. also roll it down a hill and let the clutch out movin the crank and pistons. other than that i dont know,just trial and error.might wanna check the carb also,like the slide or even the reeds.

[underpowered]

did you adjsut the valves? a valve could be partially open, i would check that. take a compression test, it will tell you alot. a stuck valve, stuck ring, will cause it to lose compresion, possibly to the point of not starting. and starting fluid wont hurt it as long as you spry some WD 40 or something in the cylinder after you do it to re coat the cylinder walls since ether dries them out.

[underpowered]

Originally posted by westhall55
i would try a hotter plug and see what you get. also roll it down a hill and let the clutch out movin the crank and pistons. other than that i dont know,just trial and error.might wanna check the carb also,like the slide or even the reeds.

Ummmmm:confused: 4 strokes dont have reeds.

[Colby@C&DRacing]

Originally posted by quadgod440ex
This isnt for a honda but i know u guys could help me out . Me and a buddy just rebuilt his warrior , 10.25 comp piston , and rings . You know the normal rebuild . nothing special no high performance valves or cams or anything , just stock bore piston . Well we got it all together , timing marks are perfect , valves are adjusted perfect , were getting spark , and fuel . but she just wont fire . when i hold my hand over the exhaust it doesnt even feel like there is compression . Never had this problem on a rebuild before . Could the rings not be seating right or something ? i know i put them on the piston right . what else could cause this to happen ? Has anyone else had a hard time ever starting a rebuilt motor ? Im deffinatly not gonna try starting fluid on a brand new motor so that is out of the question . Any help is greatly appreciated. Thanks EXriders .

PS I told him to buy a honda!

Not to sound rude but if everything was install correct and everythring is set correctly you wouldn't have a problem. You need to check again if it feels like there isn't any compression then there probably isn't. did you check the cylinder wall to piston clearance before installing a new piston? Did you hone the cylinder?

[GPracer2500]

Originally posted by westhall55
i would try a hotter plug and see what you get. also roll it down a hill and let the clutch out movin the crank and pistons. other than that i dont know,just trial and error.might wanna check the carb also,like the slide or even the reeds.

This kind of stuff cracks me up....:p

[quadgod440ex]

i adjusted the valves , to 6 exhaust and 4 intake ... The cylinder walls were honed and the piston rings clearance i was told would be fine . Did i personally check it no. Does anyone know where i can find a compression tester to fit a quad cylinder ? Thanks for any of the input . ive built plenty of 300ex motors and 400ex motors and 2 450r motors so far and ive never had this problem .

[xxnightraven73x]

well you can get a compression test kit at your local parts store they are fairly cheap.if you have low compression id check your rings if you put them in up side down then youll have no or low compression.the top of them should have an x on them.just a thought.curious to know what it is though

[spent21]

did the head get worked? maybe the valves were shot before the rebuild?
compression testers can be bought at almost every parts store for 20-30 bucks. good ones come with different adapters for different plug threads

[ohsobad_chevy]

Yup...Definately a problem with the reeds...HAHAHA :D :D :D :D
Just givin' you shiit westwall.. :) :)