Help my motor runs like crap

emoney

emoney

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Jul 19, 2010
Messages
2,551
Re: Help my motor runs like crap

You need to start at the top; Compression test, then spark test, then fuel system test. No sense in jumping around, because you can replace 15 things and scrape every knuckle you have trying to guess. Only 3 things it needs to run; compression, spark & fuel. Once you get these done, post your results and you'll get the answers you need.
 
M

Monte1961

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May 8, 2011
Messages
1,180
Re: Help my motor runs like crap

Don't think it's a 3 cylinder, I believe it;s a 2 cylinder. Ok, check for good spark, top and bottom. If good, check compression. Post results so we can assist you in the best way we can. A model # would be nice to have also. Best of luck.
 
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fishbru

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May 30, 2011
Messages
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Re: Help my motor runs like crap

Wow thanks for all the responses,it is a 2 cylinder. what is the best way to look for good spark? and how much compression should the cylinders have?
 
M

Monte1961

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Messages
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Re: Help my motor runs like crap

Get a spark tester at your local auto parts store. Spark should jump 3/8", it should snap and be blue, Compression Around 110psi or close to that + or - 10%. But in reality your looking for unity. in other words, how close are they to being the same. 80psi plan on overhaul soon. Post back and let us know.
 
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fishbru

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May 30, 2011
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Re: Help my motor runs like crap

Ok here is what i got so far, found the model #it's 2-300 hp. did a compression test both cylinders they were both at 100psi. haven't done a spark test with a spark tester yet. i did pull the plugs and checked them, they seem to be getting plenty of spark. also checked internal resistance of the coils and they were both the same. is there any way to check the CDI? thank again for all your help.
 
M

Monte1961

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Re: Help my motor runs like crap

Ok going back to original post, when you say missing? are you saying that it backfires kinda like or does it only do it at idle/high speed or mid-range?
 
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fishbru

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May 30, 2011
Messages
9
Re: Help my motor runs like crap

it doesn't backfire, and it does it at all speeds low,med.,high. it will run great for a wile then it will start missing. it does it the worst at full throttle. if the primer valve was bad and pumping extra gas in to the carb would that make it miss?
 
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Daviet

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Sep 24, 2008
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8,958
Re: Help my motor runs like crap

A defective primer could flood a cylinder, causing it to run poorly.
 
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Monte1961

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May 8, 2011
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Re: Help my motor runs like crap

Primer bulb is only for first start of the day and that's it, or at least should be. Take a spray bottle with fuel/oil mix, and a inductive timing light with you next time. Is the timing light strobing good, or is it intermittent? Check both plug wires! If all is good there, spray some fuel in the carb/s and see if it makes a noticeable change. Post back and let us know.
 
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fishbru

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Joined
May 30, 2011
Messages
9
Re: Help my motor runs like crap

when i turn that primer valve off it dumps a bunch of gas in the carb same when i turn it back on. going to diconnect the hose that goes to carb and plug it and see if that makes a difference.
 
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