GS650G running on cylinder 2 and 4.

[Anonymous]

The bike is an 1982 GS650G - Katana, have been running 55000km.

I have read all postings about this matter, but still not solved my problem.

In autom the bike was running well, after the winter it is only firing on two cylindres, -and that is not much power

Fuel Cock is OK.
Sparks is OK. (No coil problem, as 2 and 4 are running. Spark also on 1 and 3.)

Have taken out and opened the carburetors, they look like new. But I have still made a total cleaning, no dirt in any of the nozles nor the needle valve/seat.

I wonder, as an answer was given in an earlier posting, the vent tees from number 1 and 2 carb, are they to be connected to the vent line from 3 and 4? Can the lack of connection be the answer to my problem? (There are non connection at all on my bike, no mhoses connected)

Can this lead to lack of vacuum in carb. 1 and 3?

I know much is told about this earlier, but I hope someone can help me on. I will soon hit the road, hopefully with a bike running on four cylinders again.

[gs650gt]

are the plugs #1 and #3 wet or dry after the starting? have You checked that there's fuel in all float bowls? Have You tried synching the carburetors?

... just for beginning...

[Anonymous]

are the plugs #1 and #3 wet or dry after the starting? have You checked that there's fuel in all float bowls? Have You tried synching the carburetors?

... just for beginning...

Yes, the plugs are black and some wet, but not soaking wet.
There are/was fuel in the float bowls.
I have not synced yet, but the engine was running well latest in January 2005. (And there was nothing done with it before I now have take apart the carbs.

Do you know about the vents, can they give lack of vacuum, if not connected? And are they going to be connected together, i.e. 1&2 connected to 3&4 vent?

[Anonymous]

how do you know its cyl's 1 and 3 that are not working? Have you tried removing the "Vent Tee" just to see what happens?

My only experince in motorcycle repair has been on the only bike I have owned which is an 82 GS 650 I dont know how close our carbs are so I dont want to go confusing you with stuff I dont think Im even qualified to offer free help/advice for. Once bikebandit.com gets back I'll compair our carbs and give a more helpfull responce.. I hope..

When I dont know what to do I resort to a bit of an educated guess trial and error if it dosent work you can always put it back how it was, unless your like me and lose parts :? . The only thing that seemed similer to your post was this http://www.thegsresources.com/_forum...light=vent+tee And it appears as if he removed the vent hose and it worked..

What I dont understand though is how it can just suddenly not work. Did you at one time have all the vents connected with hose? Why is it only 1 and 2? Everything is just as you left it the last time you rode it?

[Anonymous]

Thank you for answering,

Well no 1 and 3 cylinders have COLD exhaust pipes coming out from the cylinders. No action at all. After some time the temperature is about 30deg. and the other two are HOT.

Regarding the vent tee's, I have got the answer. It was a miss placed posting some time ago, telling to connect together. That was wrong. It is only vent (and overflow) from the carb., I will add a tube to a "clean space".

So after remounting carbs I will sync them, if not running I will have to check intake and exhaust valves. If they are OK, the next possible fault will be piston-rings?

Or are there anyone out there with other suggestions.

[gs650gt]

If the engine was OK last autumn and nothing was done to it during the winter, we can only assume that there was something stuck or some dirt in the fuel system when You now tried to crank the engine and it wouldn't start.

And when You opened and overhauled the carbs, something can have gone wrong (slides unbalanced, float height disturbed, jets clogged etc).

I understood that the ignition and coil wires are untouched, but if You have removed them, check that You haven't made mistakes in reconnecting them... and the plugs, are they still OK?

It's a damn slow and annoying job to check the carbs but You just have to do it again and then synchronize them. If it still does not start (try set the fuel petcock to prime position... have choke on and do not touch the throttle... apply some start spray to air intake... take power from a car battery with jump cables... keep trying...), check the compression of all 4 cylinders. For accurate readings it should be done with engine warm but if it doesn't start, that's the best You can do.

Good luck!

[snowbeard]

have you checked your battery to make sure it's fully charged? could explain a weak spark.

maybe a short in the electrical to the coils for 1 and 3, the cylinders are fired 2&4 from one and 1&3 from the other. you say there was good spark, but how good was it? this would be my first clue since the numbers seem to match up with your problem. maybe clean some of the connections and see if it helds, sometimes just jiggleing the right wire can make it connect?

cleaning the carbs could be the issue, I know my crudded up carbs will give a single cyclinder not firing sometimes, but check everything before you get too far, eh?

good luck!

[Einar J Skog]

Hi

One coil fires sparkplugg 1&4the other fires sparkplugg 2&3

(Ta og bytt pluggene.helst nye.Om ikke annet s? ta og t?rk dem p? komfyren. Ta s? ? pr?v ? starte med startgass.Jeg har gjort det i starten av hver sesong.)

[robinjo]

Does it also do it on prime?
Is there enough (and good) gas in the tank?
Did you ride it yet or just start it?

[snowbeard]

oh, good thing someone's watchin out for ya!

go for the carbs, yep. :roll:

[earlfor]

When you cleaned the carbs, did you separate them and completely take them apart and soak them in a pan of solvent to clear the passageways?

Earl

Thank you for answering,

Well no 1 and 3 cylinders have COLD exhaust pipes coming out from the cylinders. No action at all. After some time the temperature is about 30deg. and the other two are HOT.

Regarding the vent tee's, I have got the answer. It was a miss placed posting some time ago, telling to connect together. That was wrong. It is only vent (and overflow) from the carb., I will add a tube to a "clean space".

So after remounting carbs I will sync them, if not running I will have to check intake and exhaust valves. If they are OK, the next possible fault will be piston-rings?

Or are there anyone out there with other suggestions.

[gs650gt]

hello, any progress ??