Samurai G13A won't idle when hot

[Larry]

Hi all,

I hoping that someone may be able to give me a little advice with some running issues I'm having.
My samurai has the original Asian carb with the compensation for lights etc. still working.
I've owned it for 5 weeks or so now and for the first 4 weeks it ran fine. sometimes the idle speed was a little slow but ok when the lights were turned on.

Last week I was out greenlining and as the day wore on it started to cut out a junctions when coasting down to a stop. Towards the end of the day it got much worse and wouldn't idle at all without feathering the throttle.

That same day it had a bad rocker gasket leak also and I wasn't sure if they were maybe somehow related.

When I got home I parked it up and ordered a new gasket. I've now changed that and the leak has stopped but the poor idle when hot remains.

During the last week I've been driving it trying to figure out what the cause is. When I first took it out it started happening after just a few miles, once the engine had warmed up. So I played with the idle speed adjustment screw until it was happy (had to turn it up 2.5 turns).

I've been driving it more since then and its much better but it still cuts out at hot idle now and again but now it only seems to happen right after its been driven hard for a few minutes. If I then take it easy for a few miles it doesn't seem to happen as much.

Does anyone have any ideas as to what the problem might be? I'm not very experienced with carbs and I'm a bit stumped at the moment. I don't really want to go stripping the carb until I'm sure it's not something obvious!

Any help is appreciated!
Thanks

[Larry]

Maybe I just need to play with the idle speed more but it just seems strange that I should have to adjust it by so much all of a sudden.

for reference the idle speed screw I've been fiddling with is the one marked in this photo which I found over on difflock. the mixture screw has a sort of sring loaded anti-tamper fastener, does that sound right?



Thanks,

[ScottieJ]

What have the temperatures been like where you are? Does it have the original airbox?

These carbs can suffer from carb icing at this time of year, that's why on the airbox there is a hot air feed to the heat shield on the exhaust manifold.

Maybe also check the fuel stop solenoid and wiring to it, normally if that's the issue they just don't like to idle at all but if it's just a bit sticky or the wiring isnt healthy it could cause occasional cutting out possibly.

[Larry]

In the midlands, so yes, its reasonably cold at the moment.

Its the original airbox, but it does has a snorkel fitted which means its not possible to have the hot air feed. Perhaps I should disconnect the snorkel and check if this helps.

I'll check the solenoid wiring also.

Thanks,

Larry

[Larry]

Just a bit of an update. I now don't think it's carb icing as it's just not cold enough the last few times I've had it out.

I think the diaphragm for the compensations may be causing this issue now. So today I've disconnected the green plug at the front of the engine, under the carb which apparently disconnects this diaphragm. Taking the Samurai to Wales for the weekend so will report back on how its running after the weekend.

Thanks,

[ScottieJ]

ah the old idle up system.......I've removed that whoel set up off a few carbs before