Thread: nitro fouled plugs

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Here is a Nitro tech question. Last week we got the nitro harley started, but it idoled sparatically. We started it 3 times for only 15 seconds at a time and never racked it up because it sounded weird. Well atfter the last shutdown I saw raw fuel running out the exhaust pipe. So we sprayed WD-40 in the cylinders for storage. I tore down the carb and found the float was off the hinge and of coarse dumping fuel heavily.

Yesterday we went to fire it up and it would not fire, it on sputtered slightly. Then after 3 tries the starter cart burned up and we could not try it again. My thought is it probably fouled the plugs from he heavy bath the previous week, and the WD-40 The owner says it could not have fouled all the plugs. Any nitrobuffs thoughts on this being possible? Nothing else was touched or changed.

Did you warm it up on gasoline or alky first??????Nitro is hard to lite and if you don't have some heat in it it won't lite every time

We used not only gasoline but a set of warmup plugs--normally ran N54 champions and warmed it up on N8y or even n9y

thanks for the reply Jerry. We are priming the carb with unleaded gasoline, about a 2 second shot from an air assisted fuel sprayer. Then its right on the 94% nitromethane fuel as soon as it fires. And we are not changing the plugs for warm up. Unfortunately niether one of us has delt with nitro and its a huge learning experience for us. We know just about enough to get us in trouble (obviously).

Am I reading your response correctly, that you warmed the motor up on methanol first, then changed the fuel for a pass? I would truley appreciate it if you could briefly describe a, from a dead cold start. The procedure you guys used.

Have the nitro tank turned off---use a hotter plug---start on the gasoline and use what ever matter you have to keep it running (continue spraying but at a rate where the engine runs decently) when you get some heat in the cylinders( may take a few minutes or more) turn on the nitro, when it gets loud shut off the gasolene spray/drip

Lots of guys would make a little gas tank that they could set on top of the blower/injector with a drip/spray bar that would put gas into the injector hat. when cylinder got heat/ turn on fuel shutoff valve, engine gets loud, shut off gas/alcohol

after engine is warmed up--do your stuff--change sparkplugs to race heat range, refill fuel tank, etc

Lots of guys would put like 30 % to 50% mix in, prime with gas and then run for warmup , drain tank/ fill with race percentage

Whatever you do know what you have for fuel in what can,etc

thanks for the advice jerry, we will try it again sunday and hopefully it goes better this time. We were heading to the track, but now they are calling for 40 degree temps, looks like it stays in my 65 degree garage for now.

The race has been postponed til next week

Originally Posted by jerry clayton

Have the nitro tank turned off---use a hotter plug---start on the gasoline and use what ever matter you have to keep it running (continue spraying but at a rate where the engine runs decently) when you get some heat in the cylinders( may take a few minutes or more) turn on the nitro, when it gets loud shut off the gasolene spray/drip

Lots of guys would make a little gas tank that they could set on top of the blower/injector with a drip/spray bar that would put gas into the injector hat. when cylinder got heat/ turn on fuel shutoff valve, engine gets loud, shut off gas/alcohol

after engine is warmed up--do your stuff--change sparkplugs to race heat range, refill fuel tank, etc

Lots of guys would put like 30 % to 50% mix in, prime with gas and then run for warmup , drain tank/ fill with race percentage

Whatever you do know what you have for fuel in what can,etc

Great advice, thanks for sharing.