85 GS700e Carb/Vacuum/Pilot Screw (?) Q's

[Jenkin]

I have an 85 GS700e and have some questions that I can't figure out from the factory service manual I have.

This was a CA bike, but all the emissions stuff has been removed prior to my having it. The service manual isn't very specific about where the emissions hoses used to connect on the carbs, but it looks to me on the head side of the carbs (as opposed to the airbox side).

I have a picture of where I think they used to go, and my carbs are physically damaged at the connection point (see pic). Also there are brass screws in that location which I can find no specific reference to in the manual, although they look to be the pilot screws for the low-side carb system, but I can't find any information on how those should be set, if in fact they are the pilot screws.

Also, there's a hose connection on the airbox side between carbs 3 and 4 which I can't find reference to in any manual or parts diagram.

It kind of makes me wonder if these are actually the correct/original carbs for the bike?

At this point I think I should perhaps look at a whole new aftermarket carb/airpod system, but am not sure what would be recommended there. The bike is in really good shape other than this carb mess (which is preventing it from running right now). Thanks for any advice.

[chris]

Hi, I would not give up on the carbs just yet as a new set will cost close to a thousand dollars, you will have to decide if it's justified. Not sure if rs34's would work for your bike but the folks at APE might know. Have you looked at the parts fiche to see the oem assembly ? If you are sure the carbs are the cause of your problems, I would take them off the bike and check everything out. The PO. might of put a dyno jet or factory pro kit in. The photo is too small to see what you are referring to as damage. Unless someone who has worked on a smog CA bike chimes in, you can set the carbs up like a non smog bike using info from older factory manuals.

[Jenkin]

Thanks Chris. Unfortunately all the diagrams/pics of the carbs I’ve seen don’t show the head-side “ports” I’m talking about, nor the hose connection between carbs 3-4. The service manual also states that the Mikuni Carb ID should be clearly stamped/indicated with the model, but it it not.

I honestly don’t know how it was running before as the petcock was not even hooked up correctly (vacuum tube was hooked up to the separator connector under the gas tank rather than the back of the petcock), and fuel would not flow out while in Prime mode. I replaced the Petcock and then noticed all the carb weirdness.

My sense right now is this is not the the right carb for the bike at all, and the previous owner miraculously MacGyver’d it into running, albeit quite dangerously and who knows how. I’ll continue to research the carb situation as I’d like to know for sure.

[Steve]

We will definitely need a better picture than the one already posted.

I have not worked on any smog bikes, so I don't know what differences there were.

As chris mentioned, it's likely possible to set it up as a non-smog bike.

I am also getting the impression that this bike is new to you? And quite likely that you have never heard it run?

Have you checked valve clearances? Yeah, it's non-related to your carb issue, but if the clearances are not proper and you have starting issues, you will have one more variable to eliminate. Might as well eliminate it now.

.

[Jenkin]

For some reason I can’t figure out how to attach a larger picture; just keeps coming in as a thumbnail.

It actually used to run well when warm; always struggled a bit when cold. Out of nowhere one day it started idling at about 4000 RPM even with the idle completely closed and smelled strongly of gas. I figured I had a vacuum leak and/or a stuck float and/or a bad petcock. That’s when I started to pull apart and realized what I was seeing on my carb and vacuum routing was way different than what was in the manual. After replacing the petcock and the intake boot rings, it again ran at high idle so I wondered if something was wrong with the low side carb settings.

I finally this afternoon found a picture of a Mikuni BS32SS online, and its significantly different from what is on my bike, so that makes sense why what I see on the bike is so different than the manual.

[Big T]

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