Tillotson HL-186A - What's up with that fixed High Speed Jet

[Go Go Diablo]

Peter - a tip of the hat to you my friend for taking the time to outline this carb in such detail. I'm sure it will help many with their understanding of this carb.

[snocatpete]

You're very welcome Bruce. But I really only focused on the high side (fixed jet) circuit of this model of carb. There's still a lot more to this carb and then there's the HL167A carb too. It is the same but little bit different! There is one more thing I would like to mention about the fixed jet. Each fixed jet .035, .039 and so on are designed to operate in a certain range of ambient air temperature and altitude. These two directly affect each other and this dictates what size of jet would be installed. Typically, a "standard" size jet will range from sea level to up to 3000 feet. If the carburetor is operated outside of this range, then the carb must be changed to a different jet.The air temperature and altitude both have an effect on what size of jet you would install in the carburetor. I could go on all day about these carburetors but hopefully the above makes some sense.

[randys444]

Very informational Pete, my brother and I just had just had his motor out of his 600. Went through the whole thing and the carb.(186A) We were also wondering about that fixed jet. Thanks for posting this info. The more we can learn about these carbs the better. With some help of a good friend we got it running nicely. Bring on the snow.