Yeah, I'm that broke at the moment I can't even buy new arms haha. I am not impressed with the Bprojects ones, they have a tendency to cross thread very easily. There are still a handful of things that need addressing but it is certainly coming along.

I found someone with a rolling road who will work with me but I'd like to get as close as possible to a tuned engine before I take it to them as they charge heavily.

Not even running the GX race head at the moment so I'm really looking forward to the power figures when it all comes together.

Cheers

The ball socket slop may be having more of an impact than first thought. The sync off idle would be out and could pose problems. Great to hear you are working throught it though. Carbs on our old cars are the soul to old car motoring. Maybe a jet size up or down and you may be on the money.... Keep going, nearly there.

Oh!! I didn't tell you.

No sht, went to a carb specialist and he said to sand then down a little back to a point. I did so and they came up okay but I could see the different conical shapes between them. So I went to the wreckers and bought some more.

Made a world of difference on the idle. I also stopped adjusting the the idle screws identically. I assumed that if you turned one you'd have to match the rest......I suppose in a perfect world maybe yes? or on a brand new carb you could assume that they would be the same but not in my circumstances.

So yeah it is still spluttery down low but when it opens up jesus-christ does it rip it up, so I can assume from that that I still have an issue with the first two circuits in that they need some fine tuning.

I also have another variable that I've discovered and that is one of the ball-sockets on the arms has a fair bit of slop in it. I'm also quite impressed with the camshaft as it really powers along.

Good news Chris. Did you also get around to replacing the Idle mixture screws?

Finally some success.

Turns out the accelerator pump is simply supplying too much, I have it on it's lowest possible setting and I doubt it even moves that much at all. Will try some smaller pump nozzles if they are obtainable. Then I guess it'll all come down to some finer balancing and some more precision tuning on the jets.

Sorry for updating this over and over but I figured if it helps someone in the future it's all worth it.

Cheers.

I was just going to pull some from the wrecks down at the yard. Might not get down there today though (got the kids) so if I can get them serviced over the counter I will.

Thanks for the chart, it appears in my circumstances I have an issue with the first two-thirds of that chart.

So, this is what's on the agenda;

Check bypass/progression holes.

Adjust accelerator pump arm.

Change pilot screws.

Hoping for some good results.

Just saw the pic of the mixture screws, they look shagged. You would be chasing you tail trying to get a good idle mixture. Can these be serviced, or are you just going to replace them.?

I would adjust the Pump cct duration and nothing else at this stage. 1 thing at a time.. Basically all the pump cct does is to fill the gap between idle and progression /main cct. The pump cct compensates for the sudden change in air flow as the butterfly is opened and the rush of air [lean condition] starts to move. The pump cct tries to level out the trough [see diagram] just after idle
As you probably already know, you only want enough fuel [correct ratio of Air/fuel] and for the minumum time required. By then the progression & main ccts should have caught up and start to meter fuel.

If you haven't seem this chart before, its very handy for a visual of whats going on.

Well here is one of the contributors to the poor primary mixture, is this from over tightening?

I didn't check or replace them when I rebuilt them. Though I know they come off all the old mitsubishi carbs so I can race down tomorrow and grab some.

Attach file:

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  Pilot Screws ZOOM.JPG (126.22 KB)

Yeah I reckon I might have to keep a log on them, seriously. Just to keep track.

Okay when I mentioned the bypass before, this is what weber calls progression holes? I checked them but I'll check them again tonight. Those are what I WAS suspecting last time. Otherwise I also think the carbs are jetting too much from the nozzles, not so much in volume but rather the time span of the injection. I read from the 2tg manual that there is only meant to be a 1.5 second injection time span, mine is at least 2.5 when the throttle is opened all the way. Hopefully that will help.

Cheers, should have an update again tomorrow.