Hot start problem

[Phantom]

Anyone had this problem? RV8 starts no problem when cold. Run it untill hot and has to turn over for ages untill it will fire up. Last night at Billing would not go at all. If you bump start it not a problem, you only have to push it half a wheel turn and it fires up. Once its running it runs fine, turn it off and you have to wait 2 hrs for it to go cold. Going to change the plugs and weeken the mixture off a bit today to see if that cures it. :hit2:

[MudSurfer]

We have something similar on our (Nina's) VW Camper - it's had a new engine with twin webbers, and when hot, it just stops, then can take a while to restart, but has to cool a little first. When I get the time, I'm going to fit a heat shield under the carbs, as I think fuel is evaporating when hot, so the carbs are fuelless.....it maybe a similar problem for you? Worth checking to see if a temp heatshield fixes it?

[Phantom]

We have something similar on our (Nina's) VW Camper - it's had a new engine with twin webbers, and when hot, it just stops, then can take a while to restart, but has to cool a little first. When I get the time, I'm going to fit a heat shield under the carbs, as I think fuel is evaporating when hot, so the carbs are fuelless.....it maybe a similar problem for you? Worth checking to see if a temp heatshield fixes it?

I have an electic Facet fuel pump that I can hear stop so I know the carbs are full. So not that. Thanks anyway.

[BUSHWHACKER]

It's caused by fuel vapour circulating in the carb on a hot engine preventing the fuel from squirting properly the next time you try and start it.
Hold the throttle to the floor then start, this release the vapour in the venturi, don't pump the pedal.

[Phantom]

It's caused by fuel vapour circulating in the carb on a hot engine preventing the fuel from squirting properly the next time you try and start it.
Hold the throttle to the floor then start, this release the vapour in the venturi, don't pump the pedal.

Cheers Vince I'll go try it.

[BUSHWHACKER]

Cheers Vince I'll go try it.

I've just read that it didn't work then.
What type of air filter are you using? It might want spacing away from the carb.

[Phantom]

I've just read that it didn't work then.
What type of air filter are you using? It might want spacing away from the carb.

K&Ns on u bend pipes about 8" long. What I can't understand is how come it fires on the smallest of bump starts.

[Brummie]

Could the problem be electrical? something breaking down with heat giving a high resistance so when using your starter no current passes but when bump starting there is enough power available to get through?
Probably talking out of my backside but might be worth checking.

Brummie

[Phantom]

Could the problem be electrical? something breaking down with heat giving a high resistance so when using your starter no current passes but when bump starting there is enough power available to get through?
Probably talking out of my backside but might be worth checking.

Brummie

Possible I guess but can't think what. The engine is simple wired and plugs, leads, distributor, rotar, coil, battery all brand new.

[MattF]

And there is actually a spark when cranking?

[Phantom]

And there is actually a spark when cranking?

Yeah checked all 8 of em.

[MattF]

Have you actually tried Mudsurfer's suggestion of using a temp heatshield for testing purposes?

[Phantom]

Have you actually tried Mudsurfer's suggestion of using a temp heatshield for testing purposes?

No but I will.

[BUSHWHACKER]

K&Ns on u bend pipes about 8" long. What I can't understand is how come it fires on the smallest of bump starts.

It starts easier with a bump because the gearbox/rear axle can spin the engine faster than the starter, so a larger volume of air/fuel is drawn into the combustion chambers.


Does it start with the air filter off?

[Phantom]

It starts easier with a bump because the gearbox/rear axle can spin the engine faster than the starter, so a larger volume of air/fuel is drawn into the combustion chambers.


Does it start with the air filter off?

That'll explain it then thanks Vince.
Not tried it with the filter off have to go and get it hot again first.