Starting Problem! :(

[tizdaz]

hey guys

ok i have a little dilemma!

the past year i aint been out with my FG much, but cut a long story short, im having problems starting it after a run.

when i 1st start it for that day, it fires up no probs after a quick prime & a bit of choke. But when i re-fuel its a nightmare to start. At 1st i thought it was my carb (jets blocked or summit) so i bought a new carb & new fuel tank at same time as i was in need of one, so with brand new carb & fuel tank fitted, same prob! so then i thought maybe a piston ring change although the performance of my engine was fine when it was running, this was my next step incase it was that, so i changed piston ring & head gasket @ same time, this didnt solve the issue either!

this was on my zen 26cc engine, i then had the oppurtunity to buy a zen 29cc 4 bolt for a good price & i was wanting a 4-bolt for sometime, so i bought it, again same problem! so it defo aint the engine/carb or fuel tank. When running it runs fine & theres no hint of a bad tuning etc, this only happens im guessing when the engine is warm/hot, its only then it becomes a b*tch to start!

the one thing i haven't tried but going to on my next outing is what i used to do with nitros.. after priming & opening the choke i will give it a little throttle when pulling the pull start, i don't remember ever having to do this over the years ive had my MB, but this is the only thing i haven't tried, i do know that my idle screw is set very low so it ticks over nicely when at a stand still so maybe theres not enough fuel getting through to the engine when im trying to start it so hopefully giving it a little throttle when trying to start it may do the trick?

my TX has a throttle hold function operated by a switch so im gunna set that to about 15% then when im ready to start it i will flick it & see what happens, any other suggestions if you have any much appreciated! ta

oh yeh, ive also fitted brand new spark plugs each time as this is usually the 1st culprit of starting probs, but this didnt help either, but like i say, 1st start of the day, its fine..2-3 pulls im away, but after i kill the engine & re-fuel, my nightmare begins! lol

 

[allanach]

After you run the car for 20 mins or so then shut it down do you notice the carb primer bulb emptys out?

I have a car that is doing this and it's heat soak, if you shut off the engine the heat goes through everything and the fuel evaporates out of the primer bulb and goes back into the tank.

You cannot start the engine untill the bulb fills back up, once the car has sat still for 10mins or so it starts back up real easy.

Hope that helps.

 

[atom3624]

After you run the car for 20 mins or so then shut it down do you notice the carb primer bulb emptys out?

I have a car that is doing this and it's heat soak, if you shut off the engine the heat goes through everything and the fuel evaporates out of the primer bulb and goes back into the tank.

You cannot start the engine untill the bulb fills back up, once the car has sat still for 10mins or so it starts back up real easy.

Hope that helps.

Hi Daz, to take the above further, weren't you talking about getting one of those alloy insulators?

Like this: http://www.davesmotors.com/s.nl/c.885035/n.1/it.A/id.858/.f

I had similar heat soak problems - engine indicating tune was OK / litte rich - yet the primer bulb was enptying.

I had found the 'teflon gaskets' are not there to make a 'superior seal' but as the 'manifold' was replacing the insulator, it was transmitting heat.
The teflon gaskets are there to try and limit this heat soak and do a very BAD job of sealing, so I had initially replaced mine with paper ones, which seaed well, but .... get the picture?

I still have the alloy manifold, but am using the teflon 'gasket' AND the normal ones. Works OK, but I don't run for more than 20-40 minutes at a time.

If I did, I would consider a long one, or simply replace with the normal plastic one. That's my thinking anyway.
Al.

 

[tizdaz]

hey

now you got me thinking. Yeh i fitted the teflon gaskets along with the ADA billet manifold, i fitted it & don't seem like theres any leak, all dry around the area which i guess is good lol

but i first had the problem a while back when i was using the stock setup etc, i think it maybe my tuning, as when i give it a little throttle when trying to start it kicks in so it could be that either my LSN is too lean or my idle is too low?

gunna give it a try this weekend see what happens, will let ya know

 

[chitown joe]

best way to see if you have a leak around those teflon gaskets is to take it off, you will see spider webbing of fuel on them if its leaking, problem with those is that if you over tighten they get deformed, under tighten they leak,
i have called ADA on these before and they said once it was tight and the manifold seemed not to move tighten an additional 1/4 turn and that should do it.
best thing to do with those is apply a very thin coat of silicone when you install them but make sure you have just enough to coat it so you don't excess in or around any carb openings.

 

[allanach]

I don't recommend using silicone around the intake of a gas engine, fuel will break it down and cause other problems.

Silicone is fine for a nito engine, hence they use silicone fuel lines.

 

[OuttaLuck]

Get rid of the teflon gaskets and replace them with paper gaskets you cant go wrong

Troy

 

[atom3624]

Daz, Troy, I did BOTH!
The PTFE or teflon gaskets are there for a reason - the alloy 'manifold' is replacing the plastic insulator.
Obviously the alloy will transmit the heat - heat soak into the carburettor - and the plastic insulator will isolate it, and stop it from being conducted back to the fuel.

The PTFE is most definitely NOT a good sealer, but it is a good insulator.

I use a paper gasket WITH the Teflon insulator - may get away with one, but will probably need one each side.
Al.

 

[tizdaz]

hi guys, if my gaskets were leaking wouldnt i see some mess from where its leaking? ive checked it over & its bone dry & clean so id say theres defo no leak?

im pretty sure now its either the tuning or coil gap, gunna check & re-align the coil gap if need to be to about 0.3mm, i know on my old engine i had it set to 3mm! (don't ask!)