Hey y'all, while doing research about the usual posts covering trying to get a little more power out of 3hp briggs flathead I saw someone mention grinding a bit off the top of your carb that stops the throttle plate from continuing to rotate. By throttle plate I mean the one that your idle screw and throttle cable attach too. Supposedly this allows the throttle butterfly to open fully. Is there any truth to this? I figure if it was a simple cheap mod It would be all over this forum. I'm a little skeptical since I don't see a lot discussion about it and don't want to ruin my carb. Thanks in advance!
Grinding butterly stop on Pulsa Jet carb?
- Thread starter Vandoog
- Start date
Well to answer my own question, I took a peek in my carb throat and saw that the butterfly was not able to open up all the way do to the lever my throttle cable attaches to butting up against the carb. I went ahead and bend it up rather than grind my carb and now the buttery can open all the way. Seems to me like it helps get a little more air and fuel in there but its so minor it is hard to feel.
most briggs and tecumseh engines 5hp and under don't open fully in stock form. I grind the stops to get them to open fully on all my carbs to get every last horsepower. its not well discussed but it helps allot. if you want more power doing some port work and shaving the head may help. and advancing the flywheels timing may help a bit. and a header is a must. but I wouldn't remove the governor unless you want to risk destroying the engine. there is no billet rod available for this engine. so revving above stock is risky. someone proposed making a billet rod in a build thread and then never followed threw. If one was available Id buy 3. also take a look at thinning out the throttle shaft if possible. I do this to my tecumsehs because the throttle shaft and the screw take up allot of space inside in the carb blocking some air flow. its a good bump in power when I'm done.