Main jets or something else?

[mrhedges]

So my project bike is an 1981 GS850G. I've had it since 2017 and posted about it. It was stolen and recovered (two years ago?). I had it going with pod filters and a basic rejetting last year. Had electrical issues and put the bike up. I got it running but it died whenever I give it gas and the idle was super uneven. I decided to check the valves and replace the pods with better quality ape brand ones. When I pulled the pods one of them had a huge tear so I assumed it was running but dying because of a vaccum leak.

Put it all back together today and idles (which it wasn't doing before) great but once I give it more the 1/4 throttle it dies. I'm assuming this is a fueling issue. I have the petcock set to prime and it's flowing lots of gas. I have been using exclusively non-ethanol gas but I haven't been using a filter and there is a tiny bit of surface rust I can see in the tank. I am assuming I have a clogged main jet? Is there anything else that would cause this issue?

 

[Nessism]

You might want to contact member Zed, for some air correction jets. Those are the cheat code to get your bike running nicely with pods.

 

[Big T]

The main jet has nothing to do with off idle fueling

Did you use a jet kit?

 

[mrhedges]

The main jet has nothing to do with off idle fueling

Did you use a jet kit?

It idle fine, it dies with throttle which is why i think the main jet is clogged. The main jets have been drilled out.

 

[unfocused]

A vacuum leak ONLY happens on the engine side of the slide, not the air filter side. A torn pod will NOT cause a vacuum leak. It will however, allow dirty air in the engine.

If you have BS34 CV carbs:
Did you bench sync them?
Did you put the black plug back over the idle jet? NEEDS to be there.
Your main jet has a lot to do with fueling. Just up from the main jet is a port that feeds your pilot jet.
Remove the slide - pull the main jet - the remove the emulsion tube - you will see this port - clean your emulsion tube very well.

If you have VM 26 carbs:
Make sure you mixture screw (under the carb in front) is about 3/4 turn out - leave this alone unless the air mixture screw below is out more than 2.5 turns out. adjust it in 1/4 turn.
Air mixture screw next to the pod filter - start with about 1.25 turns out and adjust from there
Clean the main jet and emulsion tube.

Make sure the emulsion tube is round and note oval'd

Just the cliff note - however, this should help


http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html​

 

[mrhedges]

A vacuum leak ONLY happens on the engine side of the slide, not the air filter side. A torn pod will NOT cause a vacuum leak. It will however, allow dirty air in the engine. This is very helpful, thanks!

If you have BS34 CV carbs:
Did you bench sync them?
Did you put the black plug back over the idle jet? NEEDS to be there.
Your main jet has a lot to do with fueling. Just up from the main jet is a port that feeds your pilot jet.
Remove the slide - pull the main jet - the remove the emulsion tube - you will see this port - clean your emulsion tube very well.

I have BS34 Carbs. When I recovered the bike two years ago and decided (foolishly perhaps) to stick with air pods instead of an putting an air box back on the bike. I pulled the carbs and had my good friend and very skilled mechanic drill out the jets to what it seems most everyone suggested as a good ballpark. I put it back together and it all worked. I ripped around town on the thing for months. It ran rich and the idle hung a bit but It worked and I wanted to do a plug chop and try to get it right but then I had an electrical problem, then I left town for the summer and you know life got in the way. Plus I have another bike but now that bike needs work so I'd like to get this one goin. I guess I could just pull the carbs and have him clean them again, or try to dig into them myself. I find these carbs overwhelming, so many little parts. I get the basic idea but I'm such a clutz.