i have an old 440 air cooled sled. i removed the air box because it was in the way and was wondering if i put a air filter on it should i worry about it leaning out. if it wore to lean out could i just richen the mixture by turning in the air fuel mixture screw
should i worry about leaning out?
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I would keep on eye on plugs. No, actually I'd go up a main jet size or two to be on the safe side. Then adjust/tune from there. Its better to start fat on jetting and slowly lean it out based on plug checks and piston wash than to start lean, burn it down, replace the pistons/cylinders, and start over again.
Though, it really depends on how your jetting was with the air box. If you're right on the edge (small piston wash) with the air box, then removing it might make it run too lean and burn down. However, if you're jetting is rather fat already (large wash), removing the air box will likely get the jetting closer to ideal, and it will run better.
Hmm but then again, the air box allows the motor to draw in cool air, whereas filters make it draw air from the engine bay where the air is significantly warmer (and thus less dense) so maybe you'll have to drop main jet sizes (which would indicate you're losing performance, and is the primary reason it is often better to simply gut the air box but leave it in place so you still draw cool air).
Though, it really depends on how your jetting was with the air box. If you're right on the edge (small piston wash) with the air box, then removing it might make it run too lean and burn down. However, if you're jetting is rather fat already (large wash), removing the air box will likely get the jetting closer to ideal, and it will run better.
Hmm but then again, the air box allows the motor to draw in cool air, whereas filters make it draw air from the engine bay where the air is significantly warmer (and thus less dense) so maybe you'll have to drop main jet sizes (which would indicate you're losing performance, and is the primary reason it is often better to simply gut the air box but leave it in place so you still draw cool air).
it is an old sled well ventled. on the back side of the hood there is no cover keeping the heat in. this is an older sled so its a single carb. how can i tell if she is running lean or rich
I suspect you'll be fine then. But, I've never ran a filter setup like you are, much less worked on that vintage of sled.
You have some reading to do my friend.
http://www.dansmc.com/spark_plugs/spark_plugs_catalog.html
Though this looks like a 4 stroke motor's plugs, its still a descent guide.
Spark plug readings are quick, and tell you how the jetting is at whatever RPM/load you shut off the spark at.
Piston wash shows you a more overall, long term story of your fueling. This is a little harder to check because you need to see the top of the pistons, whether by removing the head, looking through the exhaust port after removing the pipe, using a borscope through the spark plug hole, or on a piston port motor (intake goes right into the side of the cylinder, not through reeds and into the crankcase) looking through the intake port after removing the carbs and carb boot.
I don't have time to find threads that tell you what to look for with piston wash, you'll have to search on your own for that.
You have some reading to do my friend.
http://www.dansmc.com/spark_plugs/spark_plugs_catalog.html
Though this looks like a 4 stroke motor's plugs, its still a descent guide.
Spark plug readings are quick, and tell you how the jetting is at whatever RPM/load you shut off the spark at.
Piston wash shows you a more overall, long term story of your fueling. This is a little harder to check because you need to see the top of the pistons, whether by removing the head, looking through the exhaust port after removing the pipe, using a borscope through the spark plug hole, or on a piston port motor (intake goes right into the side of the cylinder, not through reeds and into the crankcase) looking through the intake port after removing the carbs and carb boot.
I don't have time to find threads that tell you what to look for with piston wash, you'll have to search on your own for that.
This helps a lot thank you for your help. So if the plugs. Show richness should i turn the fuel mixture screw more lean or should i just leave itr alone. How about if it goes lean should i richen the mixture
The fuel screw just affects the air/fuel mixture at idle. If you are lean in the midrange (needle) or top end (main jet) you will have done nothing to richen the engine by turning the fuel screw.
Straight high flow filters are usually worth about 2 main jet sizes richer. An example is the SLP high flow intakes, where they recommend 2 sizes richer.
Leaving that machine alone is the safest bet. There is no more substantial HP to be gained.
Straight high flow filters are usually worth about 2 main jet sizes richer. An example is the SLP high flow intakes, where they recommend 2 sizes richer.
Leaving that machine alone is the safest bet. There is no more substantial HP to be gained.
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