exhaust issues
Elder User
Joined: Oct 2005
Posts: 677
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If the engine stalls the power valve is cool.
Most modern performance cams runs much better with a leaner idle mixture than their stock counterparts did in stock engines.
The over 30 MPH is a secondaries thing IHMO. You may have to adjust the jetting of the secondaries up. Before the primaries were running too rich so you had the black smoke, but under accelleration you were running correctly. Wherease now you are running correctly, but your secondaries are not jetted properly for acceleration.
Do you know the CFM of the current carb is it vac of mechanical secondaries and cam profile? You need about a 600CFM carb on that engine. Does is have two metering blocks (prim and secondaries) or one on the primaries only? What tires and gears are you running?
As far as run on did you check the timing? That is either a timing or carb issue normally. If it is a carb issue consider either rebuilding the carb youself or getting a new carb. New carbs are 250bux for what you need a 600 CFM Vac secondaries carb. People charge 150 to 200 to rebuild a carb so go with new.
Most modern performance cams runs much better with a leaner idle mixture than their stock counterparts did in stock engines.
The over 30 MPH is a secondaries thing IHMO. You may have to adjust the jetting of the secondaries up. Before the primaries were running too rich so you had the black smoke, but under accelleration you were running correctly. Wherease now you are running correctly, but your secondaries are not jetted properly for acceleration.
Do you know the CFM of the current carb is it vac of mechanical secondaries and cam profile? You need about a 600CFM carb on that engine. Does is have two metering blocks (prim and secondaries) or one on the primaries only? What tires and gears are you running?
As far as run on did you check the timing? That is either a timing or carb issue normally. If it is a carb issue consider either rebuilding the carb youself or getting a new carb. New carbs are 250bux for what you need a 600 CFM Vac secondaries carb. People charge 150 to 200 to rebuild a carb so go with new.
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New User
Joined: Jun 2005
Posts: 13
Likes: 0
From: florida
I will look it up but I think it's a 650cfm with twin metering blocks. I think it could just need to be rebuilt, but it would make sense to just put on a new one for the same price, if I don't do it myself. It seems to running okay right now with the adjustments I made...thanks
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