need help possible valve problems

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wellzy
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need help possible valve problems

Postby wellzy » Sun Nov 22, 2009 9:06 am

sorted
Last edited by wellzy on Wed Mar 31, 2010 5:25 am, edited 1 time in total.
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MrBill
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Postby MrBill » Sun Nov 22, 2009 4:01 pm

Can you help with alittle more info. What is a bag of doggy dodo.
i.e. craps out at full gas, just loss of power, or hard to start?

It is not to hard to check the valve clearance.
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wellzy
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Postby wellzy » Mon Nov 23, 2009 8:48 am

ticking over it will tick over at very low revs and misfire if i leave it with fuel tap on it bogs down and cuts out, if i turn the fuel tap off whilst it is ticking over it will rev up to full revs without me doing anything and cut out once the fuel in the carb has gone.
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Postby MrBill » Tue Nov 24, 2009 6:57 am

If I understand correctly.

This is related to the fuel shut-off being on and off. I would look at a stuck float or needle and seat valve in the carb.
Sounds like your dumping fuel into the motor.

The 500's have a build-in compression release at very low RPM's that helps with making it easy to pull start by hand. if the idle is very low mine will chirp like a bird but not back fire, but with a compression release open a small amount a motor could back fire.

What color is the spark plug?
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wellzy
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Postby wellzy » Tue Nov 24, 2009 7:50 am

the spark plug is pitch black with carbon deposits which if i am right in saying, too much fuel. also the inlet between the carb and engine is wet with fuel like a little puddle. i am gona check the valves with the feeler blades them i am gona turn the fuel mixture screw on the carb by 2 full turns and see how it work then.

sorry i did not put symptoms in first post, had a long hard day.
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Postby Chadd » Tue Nov 24, 2009 9:20 am

On the sp 500 with alot of hours the exhaust cam lobe gets ground off causing the exhaust valves not to open enough. If you rev it up it will puke black smoke and act like it is running rich. pull the valve cover and inspect the cam lobe I'll bet you see it ground off.
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wellzy
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Postby wellzy » Tue Nov 24, 2009 11:39 am

checked valves all good, it seems to be running much better now??? it no longer misfires there's no backfire no smoke it's still a little rich and bogging down but i think another hour and i'll have it running like new (hopefully) don't wanna lose to a 350 4x4 honda on the next ride, said i will do a tug of war with him :twisted: :D
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Postby wellzy » Sat Nov 28, 2009 6:36 am

does anybody know which way i turn the mixture screw to reduce fuel, manual tells me what to do but not which way to turn the screw.
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Postby Quad King » Sat Nov 28, 2009 7:24 pm

Fuel screw in is lean
Air screw out in lean

A fuel screw is on the engine side of carb, air screw is on the filter side of carb.

Fuel screw will only change 1/3 and LESS throttle mixture, it will NOT change wide open
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wellzy
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Postby wellzy » Sun Nov 29, 2009 11:20 am

edit
Last edited by wellzy on Wed Mar 31, 2010 5:26 am, edited 1 time in total.
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Postby wellzy » Mon Nov 30, 2009 11:58 am

:D :D :D it's working and i have not set myself alight again :lol: :D

thanks for your help fellas, i will get some pictures up of this weekends ride. 8)
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