Technical Forum > Mechanical

bumping, jumpig engine, any ideas??

(1/6) > >>

hey every one, I wonder if anyone can help? my 2002 vara feel as though its running out of fuel. slightly jumpy and sputtery when im in the 3-4000 rev range. usualy worse in 3rd and 4th gear cruising, but can feel it in most gears. I know this is fairly low revs for the vara and have been advised to use a higher rev range but something is not right. I have repleaced both plugs and had the carbs balanced but cannot seem to get a straight answer from any one apart from "its a big v twin thats what they do!" Accleration is fine, there is a slight blowing from one of the exhaust clamps which i will fix but i dont think that would have such an effect??

does anyone else have the same problem or any ideas...  I was wondering if it is the fuel pump giving in maybe?

your advice would be much appreciated.


S Barker:
The fuel pump would be the first suspect.

If you fill the tank up you can bypass the fuel pump and gravity feed the carbs. That should either confirm or eliminate the pump as the source of the problem.


i'll give that a go, the only thing put me off the fuel pump was its not lacking in acceleration or cutting out. it seems very specific to that rev range, especially the lower gears, 1,2,3,4....

its not spluttering ridiculously, it just feels like its a bad load of fuel, or runnig out that kinda thing...difficuilt to explain



Did you ever get to the bottom of this?  If so. what was the cure?

The reason I ask is that I think I have similar symptoms.  In all gears, at low revs when maintaining a steady speed, I can feel very slight surges and dips in power giving a slight forwards/backwards rocking feeling.  As soon as you either throttle on/off, then you can't feel it.

If I keep a steady throttle whilst on the drive (on the stand in neutral) - theres a slight RPM hunting range of about 100/150 RPM with the very occasional and very slight missfire?/cough?

...Maybe I need to run it by the dealer - but first I want to really make sure that it is a problem rather than a characteristic of the bike/engine.

Any thoughts?


hey harko,

I never did get a real answer to this problem. Ive changed sparks, coils, new battery, new fuel filter, air filter, carbs balanced!! But its still there. was on a ride out last weekend and bike was fine if riding it hard, but still the stuttering thing in 3000-4000 rev range. As far as i know the carbs can be tuned although the honda people say they cant? and i had an email from a guy who knows alot about carbs, he says to change all rubber seals in carbs, check vacuums ect, i plan to take the carbs out this winter and change all rubber seals in carbs see if it works, as far as that im open to answers..............



[0] Message Index

[#] Next page

Go to full version