Do I need to re-jet?

Hey guys,

I got a 1985 vf700f interceptor that hesitates around 5k rpm and also backfires when I get off the throttle hard. Does this mean the bike is running lean? If I hold the throttle a little ways, it will rev till it gets to around 5k, and pretty much stay there, unless I give more throttle, and after a second or 2, it gets beyond 5k and revs fine the rest of the way.


I have learned that I have an aftermarket cobra f1 exhaust on the bike.Its a 4-2 system. Not sure if its "slip on" or not. I have no idea if the carbs have been re-jetted either. Should I look into getting a dynojet kit, or custom size jets for this bike? I could also throw on a k&n filter if that might help things out and/or increase performance.Thanks for any advice

 

could be a vacuum hose or carb seal leak... or possibly an exhaust leak would check those first

 

Ok, I will try and look things over really well. Is there a way of testing with a spray near carbs to see if it affect's how it runs? Is the carb seal you mention the large holes that hold the carb in place?

 

It would run just fine withh stock jetting, maybe pop a bit under hard decel. Betarace nailed it.Inspect boots to.

 

Well, I fired my bike up today I looked over the carbs for about 20 minutes today. Towards the back side of bike, in between 2 carbs, there is a metal line with a rubber hose coming out the center of it. This hose leads no nowhere. I looked and looked and looked and found no place it could go. Does this sound normal.?

Also, the bike runs exactly as I mentioned in previous post, except it hesitates any time I give it more than qtr to half inch of throttle, acting like it wants to bog and quit. I got to play with it some to get it to rev up. Is there any easy way to check for leaks? like spraying something near carbs when its running? I asked this before but nvr got an answer. Thanks for all the help

Oh and I got a newer front tire otw, and I put back on the black plastic pieces I painted..looks great

 

THE hose is a vent, no problem there, but your whole set of carbs might need a good cleaning and inspection. One or more vaccum slide diaphrams are possible suspects.