850 only running on 2 pots

[Guest]

G'day, Iam new to the forum and have made an introduction in the appropriate site. I took delivery of an 81 GS 850 G a couple of weeks ago, the bike came from the USA and it has 12,000 miles on it. After checking the oil battery forks and tyres I started it and it came off choke reasonably soon. It then displayed the symptoms I have read which is typical of air leaking into the fuel system.
The bike has no power from idle to about 4000 RPM, (have to slip the clutch and feed the throttle to it just to get it to go). Then when you have to stop the idle has gone up to about 3-4000 rpm. I have ordered an O ring kit from the USA and while waiting for it I have stripped the fork and done a polishing job on them. I just started it again and this time it started very easily but it is only running on pots 3 & 4. The exhaust on one and 2 cylinders only got just warm compered to screaming hot on on the other side.
There is a good strong healthy spark at all plugs and all cylinders are measuring over 115 lb/sq in compression. There is available fuel in the float bowl although as yet I havn't measured the fuel height.
I havn't removed the carbs yet as I have been reading the horror stories about removing and reassembling them with standard air box. Once I get the O ring set I will look forward to the epic struggle and also remove the cam cover to measure the valve gaps. An interesting note is that the bike came with a full set of brand new Suzuki carby floats under the seat so maybe the PO had been having some sort of trouble, any ideas would be greatly appreciated, regards Neil

[chuck hahn]

It needs the carbs FULLY ..and we mean FULLY disassembled and redone, new orings in the intake manifolds, and the valves adjusted. Then once all 3 are done, start it and sync the carbs with guages.

Even if it was running fine when it was bought it still has sat for many weeks waiting to be shipped and in transit. The gas probably soured and plugged up the pilot jets and pilot circuits. Be sure all 4 carbs have NEW rubber plugs over the pilot jets too...yes they really are needed.

[BassCliff]

Hi,

Check out your "mega-welcome" in your introductory thread. You will find a couple of maintenance lists. If you properly address every item on those lists you should have a safe and reliable 30 year old motorcycle. Taking shortcuts or skipping steps will lead to much frustration at least, or severe death and injury at worst.

Properly cleaned carbs, adjusted valves, air tight intake system, clean electrical connections and charging system, etc, will give you a good start. You'll find lots of "how to" guides on my little website. Welcome to the forum.

Thank you for your indulgence,

BassCliff

[3 Cav]

Thanks for your input, I think once I get my O ring kit and get to pull the carbs apart the answer may be hidden inside somewhere, at least I have 4 brand new floats to be fitted, I will keep you updated with what I find, regards Neil

[tkent02]

The carburetors and air box are near impossible to remove on some GSes, the 550s, 650s and 1100 chain drive models are a real bitch.

Your 850G on the other hand, it's a five minute job, very easy.

[Steve]

I havn't removed the carbs yet as I have been reading the horror stories about removing and reassembling them with standard air box.

The carburetors and air box are near impossible to remove on some GSes, the 550s, 650s and 1100 chain drive models are a real bitch.

Your 850G on the other hand, it's a five minute job, very easy.

Seriously, after taking out your carbs and putting them back in, you will think all the reporters of such nonsense are quite daft, indeed.

On the 850, you can just about stand beside the bike (right side, mind you) and throw the carbs into place. The only reason you can't really do that is that you need to get them into the area, then connect the cables before moving them the last couple of inches.

Yep, your issue sounds a bit fuel-related, but don't count out the possibility that spark plug wires have been crossed.

.

[pete]

Neil, if you need to do a carby clean, try to track down a bottle of Yamalube carb cleaner, it's the only one I've found to be available here and it's really good stuff!

Be warned it stinks like nothing else...

[bwringer]

Seriously, after taking out your carbs and putting them back in, you will think all the reporters of such nonsense are quite daft, indeed.

On the 850, you can just about stand beside the bike (right side, mind you) and throw the carbs into place. The only reason you can't really do that is that you need to get them into the area, then connect the cables before moving them the last couple of inches.

Yep, your issue sounds a bit fuel-related, but don't count out the possibility that spark plug wires have been crossed.

.

Agreed on all points -- removing the carbs on an 850 is easy-peasy.

It sounds like you have intake leaks and clogged carbs at the very least, but double-check your spark plug wires are correct -- it's not like a car engine, and this is a common error. The left coil feeds 1 and 4, and the right coil feeds 2 and 3. (if the coils have been replaced, left and right may be mixed up, but you still have one coil with wires going to 1 and 4 and the other 2 and 3.)

It's common for the tiny passages inside the 1 and 2 carbs to clog before 3 and 4 if a bike spends a few weeks leaned over on the kickstand.

[Dave8338]

Agreed on all points -- removing the carbs on an 850 is easy-peasy.

It sounds like you have intake leaks and clogged carbs at the very least, but double-check your spark plug wires are correct -- it's not like a car engine, and this is a common error. The left coil feeds 1 and 4, and the right coil feeds 2 and 3. (if the coils have been replaced, left and right may be mixed up, but you still have one coil with wires going to 1 and 4 and the other 2 and 3.)

It's common for the tiny passages inside the 1 and 2 carbs to clog before 3 and 4 if a bike spends a few weeks leaned over on the kickstand.

Very much happens. Center stand nearly all the time and IMHO things always run better.

[3 Cav]

G'day, yesterday I removed carbs stripped them and cleaned them with what we have available down here, ( a spray can of carb cleaner) and air blown thru all the passages. Installed all new o rings set float heights to about 22 mm. There was some crap in the left hand side of the fuel T junction which I removed. Set the idle mixture screws to 3 turns out. Assembled carbs and fitted back onto bike and hey presto It is running like a new one. All I had to do was once it warmed up I had to adjust the idle to get it to about 1000 rpm.
Took it for a test ride and it pulled strong from idle to 8000 rpm no missing or hesitation thru any of the gears. I like to post the results of things I have tried on members recommendations so to all who gave me some advice thanks very much. I am presuming the junk I removed from the T piece was starving no's 1 & 2 but I can thoroughly recommend replacing the O rings and the cleaning. Unfortunately we can't get hold of the carb dips you have access to.
The suzuki 850 G is a very nice smooth bike to ride I was really impressed, can't wait for the 1100 to arrive, regards Neil

[chuck hahn]

3 out is rather rich...at 2 it will still be just a TAD rich but will get ya better fuel economy. Least they are on the top and easy to get to.

[chuck hahn]

OH...and now that she is snorting fuel thru all the passages in each carb, throw in about 1/4 can of Seafoam or some Chemtool B-12 in the gas tank do this till the entire can is gone. This will allow PLENTY of scrubbing by the chemicals to help clean them out even better than just the carb spray did.

[Steve]

3 out is rather rich...at 2 it will still be just a TAD rich but will get ya better fuel economy. Least they are on the top and easy to get to.

When I rebuild a set of carbs, I will preset the mixture screws at three turns out.

It richens the mixture a bit to make it easier to start, then I turn them to tune the mixture, after the bike has warmed up and the carbs are synched.

Yeah, they usually end up in the 2 to 2 1/2 turn range, that "three turns out" is just to get it going the first time.

.

[chuck hahn]

My 82 1100 was best just at 2 out..a tad rich is way better than any lean as far as the valves lives are concerned.

[tkent02]

My 82 1100 was best just at 2 out..a tad rich is way better than any lean as far as the valves lives are concerned.

These screws only work at idle and very small throttle openings, too lean at idle can't hurt anything. Just get them where they idle clean and have the best throttle response. Lean is good.

Needle settings, and especially main jets, you don't want to be lean. Running lean while making a lot of power is what hurts the valves or holes the pistons.