Thumper Club Forum

Technical => Bike Problems/Questions => Topic started by: welland99 on July 06, 2017, 07:39:25 AM

Title: xbr 500 not running smooth
Post by: welland99 on July 06, 2017, 07:39:25 AM
Ive had a problem with my XBR for a while:  it is not always running smooth.  At first it was doing it only when cold and the choke was out, but now it is doing it when hot and the choke is in. 

It is mostly noiticeable at slow speeds, or at constant faster speed. When accelerating, it is not noticeable, and at 50-6-mph, the effect is much less. 

The symptoms are a kind of intermittent hesitation / surging.  It is only slight, but noticeable and annoying.  Otherwise it is running fine.  No misfiring and always starts easy with electric or kick starter. 

What are the most likely causes of this behaviour?  Interested in what you all think.  Has anybody else had similar issues?
Title: Re: xbr 500 not running smooth
Post by: SteveC#222 on July 06, 2017, 09:07:03 AM
I'd look at the carb first. Maybe a worn or partly blocked jet or airway or possibly a split or torn diaphragm in the carb (not unknown).  I had a similar problem with my lawnmower, always hunting and surging which was cured by a strip down of the carb and blowing the jets through.

On a separate note, are you still interested in that Powerbronze fairing?
Title: Re: xbr 500 not running smooth
Post by: welland99 on July 06, 2017, 11:42:57 PM
Hi Steve,
Yes, I was thinking about the carb too.  I've never done anything with mine, but maybe now is the time.....
If I remove the jets or dismantle it to look at the diapgram, how hard is it to put back together again?  I mean does it require careful adjustment / calibration in any way after reassembly, or is it just a case of simple reassembly and tightening up all screws / fasteners?

(You can probably tell that I'm unfamiliar with the finer points of carb maintenance!)

I have sent you a PM about the fairing.   
Thanks
Peter
Title: Re: xbr 500 not running smooth
Post by: SteveC#222 on July 07, 2017, 08:26:59 AM
I know it's a bit of a rave, but if it were me I'd blow the jets/airways through first then try it before messing around with the diaphragm as I would think they may be quite easy to damage and I know they are expensive if you damage them.

PM sent about the fairing.