Hi guys, hoping to get a bit of help with an H20 engine in a nissan forklift here (NH01).

Bit of back story, bought it recently for a decent price but it was smoky as heck, we had a week or so of bad weather so I jumped into it and have done a hone and installed new rings, bottom end bearings, water pump stem seals gaskets etc etc, didn't take the engine out.

All went pretty smoothly, it is running now, but not great and I'm pretty sure my vacuum circuits aren't correct (or never were). There is lots of cut and plugged hoses and nipples etc - the petrol stuff is all cut. I can't for the life of me find a manual that shows this carburetor or LPG gear I'm using, and for lack of that, a vacuum circuit diagram either. I don't know if it is standard equipment but it is all Impco, VFF30 lock off, Model J regulator, and CA100 diaphragm/carb thing. The CA100 has the elbow intake duct which goes on top of the carb which is unlabeled but resembles part no. 16010-K7800. Below that carb is another body with another butterfly inside it and all that has connected to it is a pressure nipple.

So far as I can tell the CA100 gas flow is purely controlled by a single vacuum nipple, there is no cable or linkage. So where should i be taking this vacuum line to? If I go directly to the manifold nipple it runs extremely poorly. I've found another nipple very close to the throttle butterfly (barely on the engine side, partially overlapping). Of anywhere I can connect this line to this gives the best performance. Still it is not great, and the engine seems to degrade as it heats up an I can't figure out what is going on with this whether it is a coil breaking down or what.

I don't really know where to start with it. Other than the smoke, it was running fine before I touched it. Any thoughts..?

Thanks in advance of course.
Josh