Turning over but not firing! Any ideas??

[Amante_271]

Help!!!

Ive been trying to fire up the GPX 250 Im (STILL!) doing up. Its been sat in our damp garage for about 4/6 weeks. Altho it turns over fine, all that happens is there is a slight puff of smoke/steam from the exhausts and occasionally a HUGE back-fire blasts out of one of the pipes AFTER I stop turning the engine over. Im not sure which tho.

Ive tried with the choke on /off, throttle open/shut and all the various combinations of the above.

The engine is trying to fire but it just wont catch.

Any POLITE surgestions????

[nicko600]

My first look would be the battery, I have had it before where a bike will turn over but not start, even after charging the battery. The voltage drops when trying to start the engine. I would guess the backfire and smoke would be unburnt fuel entering the exhaust, rectified by the bike starting. Try putting a known good battery on the bike to try.

[Amante_271]

I must admit I had to top up the battery water recently as it was very low, but I re-charged the battery and it took and held the charge ok.

Any other thoughts?

[Snowy]

Have you got a good spark at the plugs? What do they look like - oily or covered in fuel?

If the fuel has been in the tank for a while then change it as old petrol sucks in condensation.

I don't know this bike - I assume it's got carbs not injection? If it's got carbs and been sitting then the float or needle could be stuck giving erratic fuel delivery and flooding it.

[Genisis]

If your based in or near swindon i'm happy to have a look at it Got a GPX myself

[Amante_271]

Up date.

I got a set of new plugs from HAYBALLS in Salisbury (as I was working down that way) and she fired up almost straight away!!!!

Turns out 1 plug was cracked and the other was too wet with fuel!

Thats the good news! BAD NEWS, when I took the tank off to get at the plugs (!!!!) I found a pin prick hole in the tank! I was given as a FREEBIE a tube of tank sealant (Like Araldite!) and it seems to be holding JUST! but any better solutions would be gratefully recieved!

Genesis... Thanks for the offer, Im in Calne.

[Dabz]

excellent news...sorta! Are you any good with welding? could weld a small patch over the tank hole?

[Genisis]

I might be way out but I'm sure you can get some stuff that you put inside the tank that acts as a sealer and protects from rust etc.

[Amante_271]

Dabs.... welding and petrol tanks, especially used ones always sounds a bit risky to me!!! Anyway Ive never welded before! :-/

Genesis.... Is that a bit like the sealant you blow up tyres with? Any idea on names people???

[mike]

Try this link;

http://www.frost.co.uk/result_search...FSfxEAodqGoceA

I'm sure Hein Gericke also used to sell a sealant.