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Author Topic: Valve buildup  (Read 5132 times)

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Offline prender

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Valve buildup
« on: October 10, 2008, 09:54:14 pm »
Last session my motor seized up. I tore it down and it turns over manually. But there is alot of build up in the exhaust valve and on the top of the piston. But the walls and not scared up. I not the biggest gear head, so I'm not sure what is wrong with it. It didn't run out of oil.
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Offline Squidd

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Re: Valve buildup
« Reply #1 on: October 11, 2008, 11:09:21 am »
Have you pulled the rod end off the crank...? I'm betting you'll see something there..
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Offline prender

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Re: Valve buildup
« Reply #2 on: October 21, 2008, 09:36:48 pm »
I had lots oh honey do's before winter.  every thing looks good. I dont have a clue what the problem is. There was a little silver tint to the oil but there wasn't any scarring. everything seems to be fine
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Offline matt175

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Re: Valve buildup
« Reply #3 on: October 21, 2008, 09:54:38 pm »
Are you sure it was your motor, and not something in the driveline seizing up?
Also that race doesn't look safe, short sleeves and no gloves or neckbraces!
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Matt Hewett
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Offline prender

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Re: Valve buildup
« Reply #4 on: October 21, 2008, 10:04:46 pm »
very safe. we do it differently in the Northwest. It could be... don't know yet
I'm number 9, 11 is ours also.
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Offline matt175

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Re: Valve buildup
« Reply #5 on: October 21, 2008, 10:06:06 pm »
have you tore the engine down yet?
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Matt Hewett
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Offline mowdak1

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Re: Valve buildup
« Reply #6 on: October 22, 2008, 12:45:32 am »
I was thinking that big trackhoe and them big redwood logs in the background look a whole lot more unsafe than those short sleeves do!!
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Offline lowgalaxie

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Re: Valve buildup
« Reply #7 on: October 22, 2008, 12:51:06 am »
I use to run with some guys in Washington state that ran like that. They had fast 8 h.p. but were'nt much on safety.
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Offline prender

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Re: Valve buildup
« Reply #8 on: October 23, 2008, 09:18:44 pm »
Yeah I tore it down. I just going to rebuild it and throw her back together. The loaders aren't as bad as the pond on the side of the track. hairpin corner and a big bump after a couple races. Isn't a good combo.
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Offline matt175

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Re: Valve buildup
« Reply #9 on: October 23, 2008, 09:26:20 pm »
Quote from: Squidd on October 11, 2008, 11:09:21 am
Have you pulled the rod end off the crank...? I'm betting you'll see something there..

What did the rod journal look like? what about crank journal in block and pan? piston scared? do valves, lifters and cam move freely?
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Matt Hewett
2009 All American Mower Championships 2nd place Super Modified Twin

Offline prender

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Re: Valve buildup
« Reply #10 on: October 23, 2008, 09:42:13 pm »
The exaust valve has lots of tarish buildup. Burning on top of piston. Silver tint to the oil. But everything moves freely by hand. No scarring on walls.
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Offline matt175

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Re: Valve buildup
« Reply #11 on: October 23, 2008, 10:18:47 pm »
the "tarish" buildup is common in an engine with alot of run time on it. if there is no scaring on the cylinder walls, then more than likely the piston didn't seize up. the silver deposits in the oil are from wear, which isn't uncommon either. sounds like at the least is could use a rebuild, but do it right, dont just :"throw her together" it will never last that way. make sure you either have an arc rod, or at least a 28OHV rod, dont use the weak flathead rod. have the bore measured, and bored .020 over if needed, make sure you have a ring gap of .012-.014. and make sure you torque the rod bolts correctly, if not, it WILL fail. it sounds like something in the driveline seized up, and not the motor, but you wont know for sure unless you either take the motor completely apart, or run it without a belt on it, also make sure the belt guides didn't move, and seize on the motor pully.
hope this helps
Matt
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Matt Hewett
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Offline prender

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Re: Valve buildup
« Reply #12 on: October 24, 2008, 09:41:21 pm »
Thanks for the info.
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