hello everyone im new to the forum. just got a 1978 honda hawk cb400t first bike that that will soon be a bobber. i have been riding it but am having some jetting problems im running a high flow intake and staight pipes and wen im give it gas it will not clim passed 5k RPM i think i need to rejet the darbs but i have no idea wat size to buy if anyone can help it would be greatly appreciated


thanks

 

You need to find out what's in there first.

Straight intake, straight exhaust.... gonna have a tough time tuning that for daily riding IMO.

Start with the main jets, keeping going bigger till it pulls hard till redline.

Then your needles for partial throttle.

Then your idle circuit. Screws and maybe jets too. On an older bike you will never know whats been done till you get in there and find out. Then you can tune from there.

 

when i bought the bike the carbs were rebuilt with the stock size jets with the bike stock im starting to thing its possible to be a coil related problem thanks for the info

 

If the carbs are in fact stock and youve replaced the intake and the exhaust as you described, you are certainly going to have to re jet the carbs.

 

ok man thanks for the info