GPX hot start problems

[~starfire~]

Just been for my first extended ride (other than around the block) and got to the half way mark, turned off the engine and we I went to re-start it wouldn't fire up. Waited about 5mins and it started up. Bit of white smoke upon re-starting.
Bike runs fine other than that. Any ideas?

[Scoundrel]

How old is the bike, how many klm, when was it serviced last etc.

Temperature gauge shouldn't go up that far unless you're stopped in traffic constantly.

[~starfire~]

How old is the bike, how many klm, when was it serviced last etc.

Temperature gauge shouldn't go up that far unless you're stopped in traffic constantly.

only bought the bike on monday ... its a 1991 GPX, has had oil changes every 5k, its done 57k+, and can't remember exactly when the guy said it was last serviced.
The temp gauge isn't going up, the bike isn't smelling hot.

[Jonchilds]

Got the service history?

Hot starting problems could mean valve clearances need doing, amongst other things.
If you're mechanically inclined, you can check them yourself easily, but the GPX can be a little tricky to adjust.

A hot compression test could confirm this.

[smokeymatt]

May just need a new battery, when the bike is hot it has max compression and although your battery may start everthing well, when the bike is hot can be a different story. Once you stop the bike actually gets hotter for 5-10 mins as the water is not pumping around, this can be a problem start time, battery should be less that $50 but just check the one you have it should have an installed dateon it, if it is more that 2 yrs old you should just replace it as a matter of course. GPX is a great little bike, the problem will probably be very simple. I think the battery!
Also probably should trade if for a nice suzuki.

[noobler]

Might be not enough engine oil? I had a problem starting mine when I checked the engine oil level it was barely 1/5 up the window on the centre stand when it should be 1/2 way up.

[Nero Diablo]

May just need a new battery, when the bike is hot it has max compression

Unless the bike is not charging batteries are usally under most stress when its cold (slows down chemical reaction) and the oil is thick. Did you turn the fuel off when you stopped on such and old bike is may be the carbs have some worn parts and allows the motor to flood while is was sitting. Did you use the choke? this may no be neascary when hot and you flooded the motor. If the bike is been hard to start cycle the kill switch this often resets the electronic ignition back to the start advance and makes it a bit easier to start.

Check service history see when plugs and valve clearances were last done.

[Jonchilds]

A more accurate description of the problem/cause might be in order.

You ride the bike at cruising speeds (15min, 60-70kph?) and pull up and switch the engine off (key/killswitch?). You try and restart the bike shortly after (5min?) and it turns over (no problems?), but won't start?

[Incognito]

The bike was ridden for around 15 mins at 60-80Km/h.
Bike was turned off at filling station (key).
Fuel tap was left on (as it has been whilst in the garage, though not last night).
Unfortunately the filling station was closed (it was more to get fuel for my bike than starfire's).
Went to start the bike and has been the case whilst she was riding around the block near home, the bike wouldn't start.
It turns over, but never gets running (I have been lucky a few times to get it going with choke), almost like it has no spark, or even flooded. Kill switch and ignition off has no effect.
Left the bike for around 5 mins, and it restarted no problems. The bike starts up immediately from cold (overnight) even when it appears that the battery had gone flat from the night before (trying to restart from hot).
Oil level is fine (I checked it).
Battery terminals are clean (and now lubed).
Haven't got into the plugs yet (got no spares) haven't compression tested (haven't got a gauge).

[Jonchilds]

Any problems idling in traffic - eg, when the bike gets really hot?

[Desmo]

Heatsoak.

[Incognito]

I have ridden the bike from Vic Park to Kelmscott. I had no probs with it. It does seem to have a flat spot when you throttle back slightly at around 80, then throttle back on again..
I haven't had the bike hot enough for the fan to come on.
First night starfire was riding it, it overheated, fan came on, and it had re-start problems then, but no idling problems.

[eckythump]

I had the same problem, changed the battery and its been all good since then. Check the voltage across the battery with a multimeter and if the voltage is below 13 volts (from memory, I'd check this) you'll need a new one

Hope that helps

[Incognito]

I must admit, I was wondering if it was the battery..
When we first saw the bike, the last owner had to jump it off, as it hadn't been ran for a while.
The only reason I wasn't sure was that it behaves like the engine is flooded..

[reddog]

Valves and carb sync would be what I would look at. Might be easier to drop into Mack1 or another reputable Kwaka shop and I bet they know what it is pretty quickly when you describe the prob.

Just had a 24K service (valves, carb sync etc) on my GPX and it cost $209. Bike no longer has a flat spot at low revs and goes much better than when I dropped it off.