Ask Motorhead

1989 Yamaha SRV 540 Falling Flat

 

Question:

Dear Motorhead,

I have a 1989 Yamaha SRV 540 that has been sitting for a couple of years and I brought it out of retirement.

It ran but sluggish and I have done the following to try and correct the problem.

- took apart the carburator and cleaned it thoroughly.
- installed a new fuel filter
- cleaned the filter in the tank
- took apart the fuel pump and cleaned it thoroughly
- gave it a compression test...result 100 PSI in one cylinder and just over 90 in the other, and holding well.

My problem is that it idles well but when I give it gas it falls on its face or backfires severely.

Is this an air fuel issue or what? Any advice you can give me would be great.

Thank you,

Scott Bennett


Response:

Thanks for your email!

I would take the carb apart again and get a rebuild kit for it including all gaskets, needle and seat and any rubber O rings.

You must remove all the jets when you "clean" a carb and blow them out with compressed air - washing doesn't cut it.

You still have a carb problem. Another alt might be to get another carb off a 540 engine from a wrecker.

Good luck.

Motorhead Mark