851 runing crazy

Rogi · Sep 2, 2013

Hey guys, my 851 will start,and run great for 5 minutes or so then loads up misses. Runs like water i n gas, but I have checked that. Even changed carbes. If it dosnt die out sometimes it will straighten up and run well again for a few more minutes. It does pretty well a full throttle. I have changed points. What gets me is it runs so good when its not messing up. Any advise would be greatly apprecated.

showcrop · Sep 3, 2013

Please try to give a little more straight forward description of "loads up" and "runs like water in gas". From your description it sounds like restricted gas flow so it will run under no load condition, but not enough for any load. To evaluate gas flow with engine off and cool, make provision to catch the gas, then remove the plug from the bottom of the carb. See if it will run a quart in a half minute or so without significant slowing down.

Texas! · Sep 3, 2013

Did you change the condenser when you changed the points?

old · Sep 3, 2013

Always trouble shoot then parts not the other way around.
You need to have a good blue/white spark that jumps a 1/4 inch gap or more.
#2 you need a good steady flow of gas to the carb. Pull the drain plug and let the gas flow for that 5 minutes it takes to mess up. Catch the gas to look for dirt water etc.
Then post back what you find so we can help you more. Maybe a simple gas cap vent clogged up

souNdguy · Sep 3, 2013

at death does it still have good spark?

Rogi · Sep 3, 2013

Yes. It still has spark. By the time I check everything it will usually run pretty good for a few minutes. I have cracked the fuel line, and it leaks fuel. Tomorrow I will take it off and check the flow. Thanks I will post back.

souNdguy · Sep 3, 2013

always check spark at death.. then go to fuel if spark is good.

post back

851 runing crazy

Rogi

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showcrop

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Texas!

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old

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souNdguy

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Rogi

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souNdguy

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