Outer Limits 4x4 Board

I have an F10a in my LJ80, and I am happy with the way the motor performs, apart from the carby being an absolute cow on even the slightest angle. It must be overfuelling by the smell of it... It won't run, won't start; its fine when cold (always starts first go), but when it gets up to operating temp, the cows move in.

I don't know allot about getting carbies running great, all I have really done with this carb is pull it apart, and clean it, put it back together, and give it the best tune I could could give it the time (as it was overfuelling massivly before).

I have been told that with downdraft LJ50 carbs people did what they call a venturi tube or something, that stops the float bowl overflow floading into the venturi at angles. Is this plausible on the sidedraft F10 carby? and will it help? Or do I still just have the fuel mixture to rich? Or am I a complete nong, and what should I be looking at? any troubleshooting help appreciated

Just out of curiosity have you changed the fuel pump recently? The aftermarket on my sierra pumps out to much pressure making it run like crap and overfuelling until it stalls. Being a side-draught the fuel bowl should be sitting underneath so it shouldn't really flood over until on rather big angles. Did you replace the needle and seat while it was apart? It may not be shutting letting the bowl overfill.

Kitika wrote:Just out of curiosity have you changed the fuel pump recently? The aftermarket on my sierra pumps out to much pressure making it run like crap and overfuelling until it stalls. Being a side-draught the fuel bowl should be sitting underneath so it shouldn't really flood over until on rather big angles. Did you replace the needle and seat while it was apart? It may not be shutting letting the bowl overfill.

Thanks for your reply.
It's got the fuel pump from one of my F8a's on it, but it's still an old original Suzuki pump.

I didn't replace the needle and seat. The only thing I really changed was the power pump, which wasn't quite together right.

My G13 carby was a million times better than this thing, It really is horrible. I am seriously considering fuel only injection on the flamin' thing!

bolt a su on the side of it that, will solve your problems

You are taking the choke off when it is warm aren't you? I have a couple of LJ80 carbies in the shed and they look like pretty good carbs and are made by mikuni so should be pretty good and simple compared to the later aisin crap on the 1.3s. I would change the needle and seat normally they cost about $5 and see if that fixes it.
So your running a 1L carb on a 800cc lj motor is that correct? Or do you have the 1L from a sierra in there?

Kitika wrote:You are taking the choke off when it is warm aren't you? I have a couple of LJ80 carbies in the shed and they look like pretty good carbs and are made by mikuni so should be pretty good and simple compared to the later aisin crap on the 1.3s. I would change the needle and seat normally they cost about $5 and see if that fixes it.
So your running a 1L carb on a 800cc lj motor is that correct? Or do you have the 1L from a sierra in there?

The whole 1L from an SJ410 is in the LJ80. I am putting the choke off, though I did accidently drive it around with the choke half on the other day, and it made no real difference apart from the high idle...
OK, might pull it apart and see if I can replace it. Where do you buy from? genuine, or an aftermarket source?



Mundy, if I am not going to get the factory carb to work, I am not replacing it with another carby. Its factory carb or megasquirt with TBI

put the new needle and seat in and reset the float height as per the manual (44.5 - 46.5mm measured at 10 mm in from outer edge of float (on bottom) to float chamber sealing face (gasket removed)).


Take the needle and seat into any carby specialist and they should be able to match it up. Im pretty sure is is the same size as used on some mazda models (can't remember which one though. I might be able to find out if you really get stuck)

mrw82 wrote:put the new needle and seat in and reset the float height as per the manual (44.5 - 46.5mm measured at 10 mm in from outer edge of float (on bottom) to float chamber sealing face (gasket removed)).


Take the needle and seat into any carby specialist and they should be able to match it up. Im pretty sure is is the same size as used on some mazda models (can't remember which one though. I might be able to find out if you really get stuck)

Cheers
The float level info is really appreciated, so far I've sort of gone with an educated guess based off of the F8 carby (which has a window, the F10 doesn't )

I hopefully can figure out the needle and seat next week then

Well the carby shop was closed for the last 2 days because of a local public holiday ....

Anyway I checked my float level against what MRW82 posted, and I had it set about 4 or 5mm higher! I changed it to the specified measurement, and then took it for a drive. So far it seems like a massive improvement; so thank you heaps , cheers