First off I have inherited a motor that came with a block that was cracked. It ran when it was cracked. It had bps pistons, rods, mikuni, bps cam, roller rockers, iron mountain heads and q pipe.

The old block had 155 hours on it.

The new running block has 10 hours on it and had the mikuni and q pipe already installed.

I have now installed the old roller rockers, cam and heads.

At idle it is very erratic until it warms up then after that it appears to be burning excess fuel on occasion out of the pipe. I ordered a Carb kit thinking possibly something with a bad needle and seat. Any other ideas? I’ve tried different pilot jets and adjusted the mixture screw like the hsr tuning manual says and have had similar outcomes. I apologize ahead of time for my possible ignorance. Currently have a 27.5 pilot and 170 main.

Put in a 165 main, adjust the mixture screw (pilot screw) while it's running and warmed up. Probably be around 2ish turns from seated. That 170 is too much on top by a good bit (itll probably even be good with a 162.5, but a tad rich is ok). Adjust the idle speed after you get the pilot adjusted to get the rpms back down to around 1100 or so after its warmed up. Then adjust the accelerator pump screw so it doesnt bog off idle under load, and throttle stop with the engine off so it's correct.

#CFFITR
#GhostBoat
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If it's still erratic, you probably have a leak where the intake bolts to the heads.

#CFFITR
#GhostBoat
#Whoneedsphysicsihaveamudmotor

Thanks Russ! I will swap it out tomorrow and try. After reading and googling I probably should have re seated the valves before putting the heads on.

I have never done it but it looks awfully easy to do.

it would be in best interest to get those heads reworked, iron mountains were garbage. get with one of the builders on hear and idle issues will go away, and you'll get more stable power

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I know a guy

yeah he's pretty good.....

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