No Power when accelerating

Hey everyone, I am in dire need of some help or advice. My bike has completely lost power under acceleration. I crank the throttle
and people on bicycles could pass me on the street. I just had the carbs completely re done by Billy Carr., A beautiful job I must say, But this has not solved the problem.I have replaced the spark plugs, boots and wires. The bike idles fine, but if you put it in first, hold on to the front brake and let the cluth out, the bike will hardly spin the rear tire before bogging down and stalling. I have a repair manual, but I am at a loss at what to look at next. Any help or ideas would be much appreciated.
Thanks

 

maybe a bad vacum leak.
spray some starting fluid around the intakes and see if she revs up.
would be my fist place to look

 

Could it be a clutch issue? Do the RPMs rise like it's slipping?

 

Does it pop or cough through the carbs? More if not all info please.

 

Thanks for the info. i have always thought the clutch hasn't felt quite right. It did slip from time to time when I was riding it on the road. Now the bikes power is so pathetic and dangerous I have taken it off the road until it is fixed. It never crossed my mind that it could be a clutch problem, but now that you mention it , it is starting to make somemore sense. Thanks again.

 

Are you sure the exhaust is not plugged somehow.

 

when you are riding, not holding the brake to spin tire.
just riding and you get on it what happens?? does it still loose power????

 

WHAT YA mean like what a damn mouse left in my muffler??

 

A helluva 2000th post! :lol:

Staying tuned for more info... now that gmail isn't calling my VFRW emails spam!

 

It may sound silly but are you sure the brakes are not dragging, wheels spin by hand?

 

Weren't the older Interceptors notorious for having petcock problems that would prevent fuel from reaching the carbs fast enough? Thats what this sounds like to me... fuel starvation. Assuming the carbs are done correctly, the fuel must be lacking before them.

If it were a clutch problem, I wouldn't expect the engine to stall when holding the brake and letting the clutch out. It would slip and the engine would keep revving without transferring power to the tire. Since you say that it revs for a second then dies, it sounds like it is using the fuel that is in the bowls of the carbs to start revving, however it cannot replenish what is in the bowls fast enough and it runs out of gas, sputters, and dies.

There is also the possibility of a vent hose to the tank being plugged, but I wouldn't expect this to affect the bike immediately upon startup... You would see it after running for a minute or 10. Clogged fuel filter preventing the flow? That is if you have one.

I'd bypass the tank, filter, and petcock. Use the hose that goes directly to the carbs and rig up a small container with gas directly to this. I've got an old bottle from gear oil that I use for this. It has the tapered end that screws on it and it fits PERFECTLY into any size fuel line. I've also cut the bottom out out of so that when it is hooked up and upside down, I can pour a small amount of gas in there. The gravity feed is enough to get the gas there, and the open end insures there is no vacuum keeping the gas from flowing.

As others have said, more info would be nice if you have it. Even a sound or video clip might help us point you in the right direction.

 

Thanks everyone for the replies. There is such a wealth of information on this site. I have a sneaking suspicion that there might be something stuck in one of the exhaust pipes. After further inspection I have noticed that upon start up There is exhaust blowback coming out of the left front exhaust flange where it connects to the front cylinder head. I am going to pull the exhaust for further inspection. Besides the fact, I have finally found, after four years of searching, stock exhaust that is in excellent shape. They should be here on tuesday. I will let everyone know how it turns out, And if it doesn't work, i will get a video of the bike running posted pretty quick.

 

Hello again everyone. The bike is breathing fire once again. It turned out to be an exhaust problem. When I originally bought the bike, It had Cobra F1R aftermarket mufflers. I got a season out of these but they were really worn out. After that came the almost four year search for oem exhaust for this bike, which as most of you know it is almost impossible to find a decent set. Skip to present day, I finally found some. I loosely mounted them to see how they would fit and in doing so noticed that the two bolts that hold the common collector to the frame were missing and that the collector was sitting about one inch lower than it was supposed to. I found this somewhat odd. I took a look at a picture of the bike with the Cobra exhaust and noticed how low it hung compared to these oem mufflers. I am assuming that the jack arse who installed the cobras needed to lower the exhaust in order to make them fit. Anyways, I decided to pull of the exhaust to make sure there was no blockages. I removed the front flanges and the the whole system literally dropped on the floor. It turn out the back two flanges were not even tight. I checked it for blockages, everything was clear so I installed everything properly with the oem mufflers. The Bike has never run so well since I have owned it. UNBELIEVABLE. Thanks again to everyone for your help.