Re: engine surge CB 750
Posted by
Re-run on
Jan 18, 2012; 3:51pm
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/engine-surge-CB-750-tp3669445p3669591.html
It would not be timing. It could be a sync needs to be done, it could be that the engine is running lean.
How long since the last carb cleaning? How well does the bike accelerate? Many times this is caused by dirty idle jets causing a leaner condition. Could also be air leaks around the boots between the carbs and engine.
Pull out your plugs and look at them and that will tell you. On your 73, they should be a medium brown, some go with chocolate colored.
First thing would be to spray carb cleaner or wd-40 around the boots. If the idle changes for a couple seconds, you found the probably culprit. Your boots are either loose or hardened and need to be boiled in some water and wintergreen oil or replaced. I choose replacement as boiling is only a temp fix I think.
if no change, pull the choke a bit to see if things smooth out some. You can try running some seafoam to clean things up. If that doesn't work, then a cleaning is in order.
The ride IS the adventure. The destination is just to get gas!