7 replies to this topic

[MB1380]

Hey guys, i have a 1380 and lately i have been having a problem where i start it from cold and drive around with no problems. Then when i come back and start it again it runs badly and struggles to build up revs to the point where it is nearly un-driveable. I tought it may have been the coil but i changed if for another one and had the exact same results!
Any ideas what it could be? Thanks!

[Stevie W]

If you start it from warm after several minutes or more standing and it does this, you could have a case of fuel evaporation due to excessive heat build up with the engine off.
The fuel comes through to the carb float bowl relatively cool but if the float bowl is very hot from the exhaust manifold heat radiation this cool fuel can vaporize before it gets to the engine, hence the initial poor running.
Hope this helps!
Steve.

[86mayfair]

I sometimes get this if I stop for say 10 minutes after being fully warmed up, it won't really idle and is really rough but it goes away once you get going

[BennerW]

My 1380 is exactly the same, Very often cant get it started without abit of choke but a tad too much and idle is at 3k rpm but too little and it wont idle. get it going, close the choke and its fine.

Anyone got any solutions?

[MB1380]

If you start it from warm after several minutes or more standing and it does this, you could have a case of fuel evaporation due to excessive heat build up with the engine off.
The fuel comes through to the carb float bowl relatively cool but if the float bowl is very hot from the exhaust manifold heat radiation this cool fuel can vaporize before it gets to the engine, hence the initial poor running.
Hope this helps!
Steve.

Thanks, i mite try insulating the bowl.

I sometimes get this if I stop for say 10 minutes after being fully warmed up, it won't really idle and is really rough but it goes away once you get going

Unfortunetly this does not go away even after 15 minutes driving trying to limp home.
Any other ideas out there?

[jaydee]

Sounds more like wrong fueling, you can have this problem with too rich mixture or when waxstat starts playing up.

[MB1380]

Sounds more like wrong fueling, you can have this problem with too rich mixture or when waxstat starts playing up.

Thanks for the suggestion, ill look into the fueling. Im using a hif44 carb so that would not have a waxstat would it?

[jaydee]

Search for the 'bimetallic jet holder', but honestly i'd just try to remove the dashpot and give the jet a clean spraying carb cleaner and see if it goes better.
Usually if the engine is struggling to start when warm it could well be that its too rich, if it starts ok, but then runs rough, its most likely an ignition problem (coil, ignition module or points/condenser, wrong advance, worn plugs).
Could also be a combination of problems, this really needs further investigation.

Edited by jaydee, 03 July 2012 - 03:38 PM.