Bizarre problem.

Kitch · Post by **Kitch** » Mon Oct 22, 2007 7:05 am

OK, need a little diagnosis help please.

Symptoms: When I stop the engine, if I go to restart it after a few seconds, sometimes it wont have it at all and floods. Smell of petrol, starter wont play, huge backfire. But sometimes it'll just fire up.

If I leave it a few minutes, it'll start no problem.

Ideas? I know the air filter needs changing. Its recently had APE tensioners professionally fitted.

Air filter? Regulator? Valve timing?

Its not a huge problem, just a pain in the ass. Especially as huge race pipe backfires dont endear one to the neighbours.

Pete.L · Post by **Pete.L** » Mon Oct 22, 2007 10:00 am

I would be looking at fuel tap or float bowls first.
Sometimes you get too much fuel through cause one of the above is sticking and causes a bit of a "hydraulic lock" type effect in the cylinders.
Also all the battery terminals and wiring down to the starter should be removed, cleaned and remade.
Pete.l

VTRbob · Post by **VTRbob** » Mon Oct 22, 2007 10:34 am

just done a mates bandit with same sort of thing, the starter was worn & notchy to turn & was taking all the power from battery to turn, not leaving enough to spark cdi, not saying thats what it is but might be worth having a look.

Kitch · Post by **Kitch** » Mon Oct 22, 2007 10:37 am

Aye, sounds like its gonna be one of those "could be anything" jobs.

I'll have a look at the fuel system and the basic electrics, then give up and let a mechanic sort it

Cheers for the ideas so far, I'll see how it goes.

Post by **sirch345** » Mon Oct 22, 2007 10:55 am

All of the above are possibilities

If it were me I'd check the easiest and cheapest things first

If your air filter needs changing anyway I'd get that done.

Try a new set of spark plugs.

Check also connection of HT (high tension) lead to each spark plug cap. If they look suspect just cut 10mm off the HT lead and re-connect.

Sometimes plug caps can break down and cause the spark to go to earth rather than all of it to the spark plug.

If the battery is struggling to turn it over it could be the battery itself (check it out with multi-meter)

You also mention the Rectifier/voltage regulator. If you've still got the original standard one definitely have a look at that. (visual check for signs of melting, then check ouput at battery with multi-meter)

Chris.

KarlosVTR · Post by **KarlosVTR** » Mon Oct 22, 2007 5:48 pm

try the fuel tap diaphragm

Stormin Ben · Post by **Stormin Ben** » Tue Oct 23, 2007 12:47 am

Try not turning the bike off and then back on again a few seconds later!

If you are going to ride off again imminently, dont try & save 3 seconds worth of fuel, just leave it running

Teehee

solorider · Post by **solorider** » Tue Oct 23, 2007 1:27 am

had a cbx550 a few years ago which if switched off for about 20mins would not start,after cranking the engine there would be a big bang fon the exhaust and the bike would start,the cause i believe was the cdi unit but i sold the bike before i could fix it

Kitch · Post by **Kitch** » Tue Oct 23, 2007 7:21 am

Stormin Ben wrote:Try not turning the bike off and then back on again a few seconds later!

If you are going to ride off again imminently, dont try & save 3 seconds worth of fuel, just leave it running

Teehee

Yeah officer, I left it running while I dropped this DVD off at the rental place, and when I came back it was gone...

storminateacup · Post by **storminateacup** » Tue Oct 23, 2007 10:38 am

How fast is you tickover

or do you give it a blip before killing the engine

Both these things leave excess unburnt fuel in the cylinders that can make the plugs wet preventing starting until the residual heat in the cylinders vapourises the unburnt fuel which only takes a minute or two.