compression too high

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jtyler1998

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sperry ok
i rebuilt the my warrior last winter. i put in new rings,gaskets, cam, cam chain, and i also rebuilt the carb. it was still doing the same thing it was doing when i got it. when trying to start it, it backfires really bad and tries to start for like 3 seconds. it has really good spark and is getting plenty of gas. i messed with the carb a lot and that didnt change anything so i got a compression tester and checked the compression. the compression tester says it has between 140 and 145 psi. my clymer manual says that 120 is standard and 128 is maximum. what would cause it to have high compression and would it cause it to not run?
 
That is really good comp won't make it not run
sounds like your timing is off check your timingand make sure it's on
 
the timing is set perfect. i've checked it many times. after i did some research i thaught it might have bent a valve because when i got it the cam pin had broken and fell into the crankcase. that was why i decided to rebuild it but when i had it apart the valves and everything looked fine so i think that was the problem. i did he comp test to be sure and it was really good. i am going to get a new carb because mine is in pretty bad shape and after about 3 seconds of turning it over it doesnt try to start and the plug is soaked in gas. is the carb doing this or could it be something else?
 
could be erratic spark from a bad pick up coil in the stator or just a bad ground or wire rubbing on frame and grounding out
 
cracked carb boot? Backfire with that compression could have blown it out.
 
The carb boot looks pretty good. Can't see any cracks anywere.
After we rebuilt it we pulled it around with another four wheeler and it did start and idle but would barely stay running and wouldn't take any throttle.
I think I'm going to take it to my local yamaha shop and have them look at it.
Thank you for your help.
 
Motors only need 3 things to run, brother... Ignition, fuel, and compression... If you have good ignition, already know you have good compression, it's in the fuel delivery. Sounds like a jet is plugged... Did you blow air through all holes in the jets? And one more thing, I've come across this... Check your exhaust for blockages. Had a plugged tailpipe on 2 different dirtbikes that would act the same way.
 
gawarrior said:
Motors only need 3 things to run, brother... Ignition, fuel, and compression... If you have good ignition, already know you have good compression, it's in the fuel delivery. Sounds like a jet is plugged... Did you blow air through all holes in the jets? And one more thing, I've come across this... Check your exhaust for blockages. Had a plugged tailpipe on 2 different dirtbikes that would act the same way.
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Thats an interesting comment about the plugged exhaust.. Could be a dead mouse jammed in there or sumthin?

I was thinking that it sounds like its starving for air.. The 3 things I was always told you need to make a motor run. Fuel, spark, and air..
Just say'n. lol
 
Actually, it was either a bird nest or a rat nest in both of them... My warrior sat under the same shed for about 3 years at my dad's. When I brought it home, put a battery in it, and turned it over, acorns shot out the exhaust like BB's... No Sh!t... That thing has a whole lotta compression, though, could blow all that crap out... Actually put a small bruise on my 12 yr olds arm... Other weird things I've seen... Got the DT 175 running after cleaning exhaust, it would run great for 5 min then shut off... Repeatedly... I had just rebuilt the carb, knew that wasn't it... Finally figured out a dirt diver made a nest in the vent line on top the gas tank... It would run until it pulled a vacuum in the tank, then couldn't get no more fuel...
 
I've had both of those issues^^^. It is cool to see that crap shoot out of the exhaust though! I had a customer complain that there carb was acting up on a 360 prairie. Acted like carb, plug, or air filter. But, the belt like was on, and I had just serviced it not long ago. Figured there could be a limp mode to prevent belt damage. Took the belt cover off to find a mouse nest and what was left of a mouse mashed into the belt and sensors. What a way to go.
 
gawarrior said:
turned it over, acorns shot out the exhaust like BB's... No Sh!t... That thing has a whole lotta compression, though, could blow all that crap out...
Click to expand...
LMFAO. :haha:
I bet that was something to see.. It sucks your little man got hit though.

Gen1Pat said:
I had a customer complain that there carb was acting up on a 360 prairie. Acted like carb, plug, or air filter. But, the belt like was on, and I had just serviced it not long ago. Figured there could be a limp mode to prevent belt damage. Took the belt cover off to find a mouse nest and what was left of a mouse mashed into the belt and sensors. What a way to go.
Click to expand...
I woulda charged extra for the dead critter removal.
 
Mathius said:
LMFAO. :haha:
I bet that was something to see.. It sucks your little man got hit though.
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Thanks, but I'm not too worried about my boys...They are all country... Put eye and ear protection on, it's time for Red Ryder BB gun war!!! I still say they're wusses, though... When we were kids, we didn't wear not pansy goggles...
 
Gen1Pat said:
I've had both of those issues^^^. It is cool to see that crap shoot out of the exhaust though! I had a customer complain that there carb was acting up on a 360 prairie. Acted like carb, plug, or air filter. But, the belt like was on, and I had just serviced it not long ago. Figured there could be a limp mode to prevent belt damage. Took the belt cover off to find a mouse nest and what was left of a mouse mashed into the belt and sensors. What a way to go.
Click to expand...

I know what ya mean. Every few months my dad and I have to clean the dead mice in the ac in my mom's car. I tell ya that is not a fun job picking those frigging things out of there :tdown:
 
Put rat poison on the top of the engine. Tape it on there. What is worse is when they start to chew the wiring harness.
 
Gen1Pat said:
Put rat poison on the top of the engine. Tape it on there. What is worse is when they start to chew the wiring harness.
Click to expand...

Or die and fall on the exhaust manifold...Then you drive not knowing... Damn what a stench...
 
gawarrior said:
Thanks, but I'm not too worried about my boys...They are all country... Put eye and ear protection on, it's time for Red Ryder BB gun war!!! I still say they're wusses, though... When we were kids, we didn't wear not pansy goggles...
Click to expand...
I remember have'n neighborhood bb' gun wars when I was a kid. It would go till someone started cry'n, and the street cleared. lol
 
You say the timings fine and the boot is too. Its gotta be a fuel or air issue, most likely fuel.

Whats your jetting set at? Whens the last time the carb was cleaned?
 
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