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Discussion Starter · #1 ·
I have a 1999 Magnum 500 just rebuilt the carb and my issue is when the bike gets hot it won't run. it seems like there is no fuel as it will die and then if you put the choke over to full it will start but not go anywhere. once the thing cools off it will run fine. Has anyone else had this problem? :wtf1:
 

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Hey welcome to the board! Hey I was just up there Friday and Sat. for 14 year old baseball at your High school!
 

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Nope!
 

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Check your vent lines and stuff at the gas tank make sure they arent pinched or anything. Also what kind of fuel are you using? We have had these machine vapor lock before. Try using a better grade of fuel and see if that helps.
 

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Discussion Starter · #6 ·
I have checked lines adn all this fines. I'm using 87 octane but maybe will try something different. I have tried many things and one thing that blows me away is I can not use a K&N filter anymore. I used one back in the day but the bike just won't go with a K&N any thoughts? So I am using a stock filter and bikes seems to be doing ok for now. Carb has been rebuilt and as stock 157.5 jet in it.
 

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I don't know very much about these machines but aren't you suppose to be using 93 octane in them? It's 2-stroke right?
 

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Oh my bad, nevermind then. Haha
 

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My 95 Magnum 425 just started doing the same thing. After about 20 minutes of riding it starts to run rough until it eventually stalls. I had my son clean out some caked mud in the radiator hoping it fixed it but haven't tried yet. Will be interested in your fix.
 

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Discussion Starter · #11 ·
I rebuilt the carb and still had isues then I had the ECT cable re-routed and was able to adjust the idle and now all seems fine. with the exception of I can t run the unit with a K&N filter it just won't go. Have to use stock filter.
 

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changing to a hi-flow air filter or opening up the airbox, will cause you to run "lean" and you'll need to re-jet the main jet to a richer one ( bigger) and may need to raise the needle jet and turn the fuel screw out a bit.
hth
Rick, Ore :buttkick:
 

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try some marvels mystery oil in the gas tank
sounds like valves are sticking with carbon
when it quits listen closely for a click as it cools off then if it starts up
its carbon on valve stems marvels will fix the problem Tim
 

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What about checking compression? Check it when cold? Then check it when the engine stalls out? Compare the readings. If different you might have worn rings or cylinder wear. That is just a thought. The reason behind this is the fuel is pulled to the carb from vacum created by the engine. Therefore low compression could cause this. That is my thoughts.
 
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