enigne performance

~DarkNemesis~ · Post by **~DarkNemesis~** » Thu Nov 29, 2012 9:04 pm

this seems to be a carb issue and may be.... runs greats at idle in usual forward motion. Runs great at high end untill you trottle back. Soon as you trottle back to stop or slow down.... she chokes and or dies. Only ways to keep her going is to restart and or baby the trottle untill the engine has cooled down. The typical 3 turns out on the idle screw doesnt help. Carb has an electronic choke. Maybe the choke box needs replaced? Still doesnt seem to make sence. Carb is fresh rebuild minus the choke. gas all new. filters new. fuel system new all togather..... any possibility the intake manifold has cracked? thanks for replies, its not super important just one of those cuold be, maybe issues....

RWS · Post by **RWS** » Thu Nov 29, 2012 9:10 pm

Jeff,

Sounds like a needle valve/seat/float problem

Could be a simple adjustment or worn part(s)

RWS

larryeddington · Post by **larryeddington** » Thu Nov 29, 2012 9:23 pm

Seems if intake cracked would be a vacuum leak and engine would backfire when accelleration tried.

I would start my idle screws starting at 1.5 turns out from bottom and work from there. You are on the right track it seems to me to be a carbureting issue.

The choke even when electically disengaged can be manually adjusted to tich or lean. Once engine warm no chocke should be needed.

~DarkNemesis~ · Post by **~DarkNemesis~** » Thu Nov 29, 2012 9:24 pm

thanks for the reply RWS, all parts are brand new, maybe a simple break down and relook? that will cost more? adjustible externerally?

~DarkNemesis~ · Post by **~DarkNemesis~** » Thu Nov 29, 2012 9:26 pm

thanks Larry, all I know is to go 3 out from a snug set. Ill try it back in to 1- 1/2.... I think the carb build was bunk or picked something up that has got stuck.....grrr

RWS · Post by **RWS** » Fri Nov 30, 2012 6:07 am

Jeff,

A vacuum guage would be a valuable diagnostic tool in this case.

RWS

guglielmo6160 · Post by **guglielmo6160** » Sat Dec 01, 2012 10:43 pm

sounds like a fuel delivery issue,
start with the basics, work your way to complex stuff. from what your describing sounds like fuel cutoff, feathering the throttle is a sure indicator of that. I know its a pain in the ass, but try running that engine with a seperate fuel source and an electric pump to see if the problem is the same, then you can rule out a pump and fuel delivery issue

larryeddington · Post by **larryeddington** » Sun Dec 02, 2012 9:31 am

I believe he is running the engine on the hard, ergo seperate fuel but could be fuel pump anyway as you suggested.

~DarkNemesis~ · Post by **~DarkNemesis~** » Sun Dec 02, 2012 6:18 pm

engine is on the hard (Bench). Pump was rule out first. Have not had time to tinker much. RWS had a great tool idea. It has checked out ok. Should have a solution this next weekend. Thanks guys, for the help....