New Jets Question

[AaronA1]

Hey everybody! I am in the final stages of getting this motorcycle going....FINALLY. I have pod filters and a 4 into 1 exhaust. It has the stock jets....and the bike won't start. If I am understanding what I have been reading, I am going to have to replace the jets on the bike, correct? I have a 1978 CB750. The bike is definitely bringing in a lot of air....and I'm getting spark....but I guess not enough gas.

The stock size is 110, does anybody know what size I need to jump up to with the pilot and main jet?

Thanks for any help!!

 

[dirtdigger]

The jetting wont cause it not to start unless they are completely blocked. Most of the time you wont even have to change the pilot jets with just pods and exhaust. The mains will more than likely only have to go up 1 size but like has been said in several other posts you have to run it and see how it runs and check plugs and adjust from there. There are to many variables that determine what jetting will have to be. Altitude, temp, motor condition, fuel quality all have major affect on jetting. You have to jet bike by bike, no two bikes will require the exact same jetting if you want it jetted correct for optimum power and drivability.

 

[AaronA1]

Thanks for the reply! I guess since the jets are not blocked at all, and I'm getting spark, and air, and I'm pretty sure I'm getting gas. What could be other variables that are making my bike not want to start. I kick it, and I can hear the compression, I hear it pull in air, but it doesn't fire. Everything on this motor has been completely cleaned and I did all new wiring. If I spray something in the air part of the carbs, it tries to start, then does after about 2 seconds. It ran for about 10 seconds when I first initially tried firing it. I'm at a loss and can't figure this out!

 

[dirtdigger]

Make 100% sure you are getting fuel to all carbs then check to make sure the choke is closing all the way on all 4 carbs.

 

[tommycarl]

Since you did new wiring I suggest that you be sure you have the yellow and blue wires connected from the correct coil to the correct set of points.