Thumper Club Forum

Technical => Bike Problems/Questions => Topic started by: pitza on October 19, 2007, 06:18:10 PM

Title: XBR 500 Breakdown, No Comprssion
Post by: pitza on October 19, 2007, 06:18:10 PM

Hi all,  On the way to work the other morning my XBR 500 suddenly decided to pack up and to cut a long story short I have a very weak spark and no compression! What do you think the problem is and what can be done please?      Thanks in advance  Pitza.

Title: Re: XBR 500 Breakdown, No Comprssion
Post by: guest295 on October 20, 2007, 07:59:07 AM

Broken cam chain? Jammed decompressor? Don't worry about the spark until you get the rest sorted.

Title: Re: XBR 500 Breakdown, No Comprssion
Post by: pitza on October 21, 2007, 03:06:29 PM

When I disconnect the decompession lever there is still no compression.

Title: Re: XBR 500 Breakdown, No Comprssion
Post by: pigafetta on October 21, 2007, 07:43:29 PM

Remove the 'valve-tappet-inspection-hole-cover-wotsit' near the decompressor lever and look in the hole to see if the valve lifter's working when the decompressor lever's pulled. It might be jammed open.

Title: Re: XBR 500 Breakdown, No Comprssion
Post by: guest295 on October 22, 2007, 08:10:37 AM

and, obviously, turn the engine over to see whether the valves are moving and whether one of them is jammed open.

Title: Re: XBR 500 Breakdown, No Comprssion
Post by: xbruby on October 22, 2007, 03:20:51 PM

Best thing to do is whip the rocker cover off and take a good look, should be reasonably clear if the decompressor is sticking. Have you visually checked the external action of the valave decompresssor? Is it moving freely or sticking?