Topic: 77 cb750 SS Loss of Power

[chevy357]

Hey I have a 77 cb750. It has about 45000 miles on it.  I've had it for about 6 months now, and it's been running great. But the other day I started it up and while going down the road I couldn't get it to run over 4K in 3rd gear and up. It would just bog like crazy. 1st and 2nd will rev out but seems sporadic and pops a little, if that makes sense.  It still idles good though.  I'm complelty lost on this issue because its been running great then all of a sudden this happens. The day before this happened I was riding it kind of hard and while coming down a hill by my place I let the transmission slow me down and I noticed a lot of smoke coming out of my exhaust, not sure if that has anything to do with it.

Any help on my issue is greatly appelreciated.
Thanks
Ben

[Rigid]

Might have picked up some sediment in the float bowls and plugged a jet?  That smoke description can't be good but may be unrelated.

[BeSeeingYou]

Could be restricted fuel flow.  Are you running inline filters? Check for junk in the tank, carbs, and any filters.  Might be time to clean out the whole fuel system.  The smoke could very well be from worn valve guides.  Well known problem with the 77/8 SS.

[jtb]

Could be restricted fuel flow.  Are you running inline filters? Check for junk in the tank, carbs, and any filters.  Might be time to clean out the whole fuel system.  The smoke could very well be from worn valve guides.  Well known problem with the 77/8 SS.

[/color]

+1

Smoke definitely sounds like valve guides.  I never had the boggin problem, but my valve guides were so bad, I would loose one cylinder after 25 miles due to fouling.  New plugs, too.

[chevy357]

Hey, Thanks for your replies.  I am running a inline fuel filter.  I've already had to change it out since I rebuilt the bike because it got plugged up with black junk from the tank.  As far as the plugs I just checked them a couple weeks ago, and they looked fine.  I will have to check them again though.

Thanks for the help.
Ben

[steam-powered man]

try these one at a time:
clean the in-tank sock filter
try removing the air filter from the airbox
flip open the gas cap when it's bogging
check points/timing;

[BeSeeingYou]

It's time to clean the tank.  You are just putting a bandaid on it by changing the inline filters again.   A properly cleaned tank and the stock petcock filter is all you should need.