Hi all I've searched all I could but I don't know what to adjust on my carbs to give them more power at lower throttle position. Under 1/4 throttle I have weak power, but she idles fine and pulls really strong over 1/4ish to WOT. Right now main is 145 idle is 38. I have a short baffled exhaust and velocity stacks. This is newly rebuilt engine, .25 over and I cleaned the carbs really well! I'm still breaking it in, compression is 170 currently. Upon my first ride today, the engine wouldn't respond until I opened up the throttle quite a bit, but when she idles, she can seemingly rev fine... So how to I get more power out of low throttle position? Thanks!
Cb450 weak power under 1/4 throttle
- Thread starter DHolbrook
- Start date
mydlyfkryzis
当有疑问时踢你的敌人在生殖器上，你可以道歉后
May be a fuel mixture problem....
What do the plugs look like?
You may be too lean or too rich at the 1/4 throttle position.
The CV carbs have 3 circuits that overlap. Slow, main, and secondary main.
1/4 throttle is the transition from slow to main....
With stacks and short mufflers, you just may be in a bad spot in the carb.
It is very difficult to get these carbs to transition well from other than a stock configuration.
I have no specific ability to help you here, but I've read and seen this issue all over the place.
I believe most people end up putting up with the issues, as I rarely see any posts that show the owner getting the bike running as good as stock.....Like you, they put up with the problem, and focus on where it does well.
It may also be carb synchronization. Carb sync affects lower throttle much more than high throttle.
What do the plugs look like?
You may be too lean or too rich at the 1/4 throttle position.
The CV carbs have 3 circuits that overlap. Slow, main, and secondary main.
1/4 throttle is the transition from slow to main....
With stacks and short mufflers, you just may be in a bad spot in the carb.
It is very difficult to get these carbs to transition well from other than a stock configuration.
I have no specific ability to help you here, but I've read and seen this issue all over the place.
I believe most people end up putting up with the issues, as I rarely see any posts that show the owner getting the bike running as good as stock.....Like you, they put up with the problem, and focus on where it does well.
It may also be carb synchronization. Carb sync affects lower throttle much more than high throttle.
Wow thanks for the info! My plugs seem a little rich, but I haven't done a plug chop really well yet because I can only get to wot for about 4 seconds until I need to cut out and coast into my drive way. I think I'll get some uni filters and change one of my 145 mains back down to 130, then do a proper plug chop and see how the plugs differ and go from there.
Redliner
Over 1,000 Posts
If you have a timing light, I would play with the points plate to see if it makes any improvement.
Try to advance it 2º from wherever it is now. Then retard id 2º if that doesn't help. You will have to readjust your idle.
Thoroughly clean your plugs after each adjustment.
Let us know.
Try to advance it 2º from wherever it is now. Then retard id 2º if that doesn't help. You will have to readjust your idle.
Thoroughly clean your plugs after each adjustment.
Let us know.
