Jet size

[bigkelk9]

So I posted this in technical and saw it wasn’t on the board. Not sure of how it all works anymore since the site was changed years back.. so let’s try again and see if I can get some input
So, had to tear down the carb, finally got the beast up and going but the carb isn’t right, so tearing it down to clean it up. Just curious as to what size jets to use. As some may know, bikes been bored and has Carillo Pistons, changed to the 600 cam. Heads have been gone through and replaced valves with valves to match what I have as well as spun drop to increase compression. So any suggestions as to what size jets I should use. Thanks in advance

 

[HMAN]

Jet size

So, had to tear down the carb, finally got the beast up and going but the carb isn’t right, so tearing it down to clean it up. Just curious as to what size jets to use. As some may know, bikes been bored and has Carillo Pistons, changed to the 600 cam. Heads have been gone through and replaced...

www.bigdogbiker.com

 

[mleach72]

Kel, it's hard for anyone to give a good suggestion because every bike is different, depending on exhaust, ac, plus your motor work. Elevation also makes a difference. The best advice I can give you is to follow the tuning manual. Through some trial and error, you should be able to get it eventually. Make sure you don't have any intake leaks or missing rubber caps on the carb and/or manifold. They will make tuning impossible.

 

[bigkelk9]

Kel, it's hard for anyone to give a good suggestion because every bike is different, depending on exhaust, ac, plus your motor work. Elevation also makes a difference. The best advice I can give you is to follow the tuning manual. Through some trial and error, you should be able to get it eventually. Make sure you don't have any intake leaks or missing rubber caps on the carb and/or manifold. They will make tuning impossible.

Appreciate that, but yeah didn’t include I have the typical exhaust everyone throws on these k9’s without baffles…

 

[mleach72]

Appreciate that, but yeah didn’t include I have the typical exhaust everyone throws on these k9’s without baffles…

That's probably your problem right there. Everyone likes a loud motorcycle, but running with no baffles creates some problems, especially when combined with a performance cam like the 600. The late closing exhaust valve is allowing the piston to suck exhaust back into the cylinder at the beginning of the intake stroke. Baffles keep the exhaust from reversing direction. No baffles create a big tuning headache. There's usually a big loss in torque as well. You might want to try the Big City Thunder baffles. The exhaust will be louder than the original baffles, but you will still get some of the benefits that baffles provide.

 

[bdm7250]

Hey Kel, with my motor mods and 630 cam I am running 32/84. You're gonna be trial and error until you find the sweet spot.

 

[mittens]

I just swapped to a 600 cam in a 107. I have short open pipes,.. Running a 31.5, and a 76 main with a 50 air bleed. Runs fine need to check fresh plugs. 84 main is HUGE/