1982 GS750T losing power

[Guest]

So the other day I went for a nice ride with the wife and everything went well l. Got home and parked the bike for a couple hours. Decided to take it for another spin and got down the road 1/4 mile and the bike started to lose power at half throttle. Almost like it's starving for fuel. The carbs were cleaned at the shop this spring and I'm getting spark. Any suggestions?

[tkent02]

Try putting it on Reserve.

[GSXR7ED]

What's the gas gauge indicate? If you're less than 1/4 tank, do as tkent suggest. (Do as tkent suggests anyways) If you're more than 1/2 tank and it's doing that, maybe you need a new petcock. I've had no issues with my "T" and have not needed to put the fuel petcock on RSV.


Ed

[Squatch]

The tank is full of fuel and will sit and idle like a champ, it's just when I'm giving it more than half throttle.

[GSXR7ED]

Do you have a fuel filter? Check the vacuum line from the petcock to the #2 carb. Turn the petcock to reserve as tkent suggests. If it's starving for fuel, check all connections from the tank the petcock to the carbs.


Ed

EDIT: Even the throttle line. One time, I had a blockage that prevented revving. Check that the throttle cable isn't blocked.

[Nessism]

How is the charging system?

[Squatch]

OK so I changed the plugs today just to make sure it wasn't that and it's not firing on 2 cylinders.... could it be the coil? If so where would I find one?

[geol]

Do a little trouble shooting before replacing parts as it always costs less to replace only bad parts than nilly-willy replacement. Which two cylinders are not firing? The Suz is a lost spark bike and two cylinders fire off one coil; that is 1&4 and 2&3. If you lost cylinders 1 & 2, that doesn't point to coils but something else. If you lost 1 & 4, then that points to a problem associated with that coil or the electronic ignition. If you lost 1 & 4, you could swap the leads from the igniter pickup coil and swap plug wires and see if the problem moves to the other two cylinder (2 & 3). If it does, it just may be the coil. If not, there is a problem with the igniter. Also, you may want to turn the key on and check to see if you have voltage to both coils. There are two plugs under your tank that have each two wires. One wire is from the igniter and the other is an orange/white wire that carries power from your kill switch to your coils. Unplug and use a test light or multimeter to see if you are getting 12V with the key on, kill switch on and bike not running. If you are getting no voltage on one of the two coils, this would indicate a bad connection.

[Squatch]

OK so it's the two left side cylinders. Forgive me for not knowing what number cylinders those are... I'm kinda new at this. I've worked on cars all my life but this is the first bike I've ever worked on. Whatever it is it seems to be getting worse. It won't even idle now.

[JTGS850GL]

If it's the left two cylinders (1 and 2) then it's more then likely a fuel issue. Probably time to do a carb rebuild. If it were an ignition problem then it would be 1,4 or 2,3 effected. How did you determine that it's 1,2?

[Squatch]

Because the manifolds for the two cylinders on the clutch side are cold and the two throttle side are hot

[Squatch]

OK so I'm getting spark... it's gotta be a fuel issue... guess it's time to pull the carbs and see if I got some junk in them. They were cleaned and rebuilt this spring but coulda got some dirty gas or something I guess.

[JTGS850GL]

Because the manifolds for the two cylinders on the clutch side are cold and the two throttle side are hot

Yep, it sounds like it time for a carb rebuild.\

Just for reference, The cylinders are numbers 1-4, left to right, while sitting on the bike.

[Squatch]

Thank you for the help. I'll post my results after I pull the carbs and get my hands dirty. Also I know this is off topic but I'd like to put a 4-1 exhaust on my bike. Where would be the best place to find one at a reasonable price.

[GSXR7ED]

Sounds like you're going for the gusto in a quick amount of time. Take care of the Carbs first...getting her up to par can be an enjoyable process once you take care of the essentials. How are the brakes? Do you have the old style rubber lines or are they braided? It's something to consider upgrading to but if you aren't having problems and the rubber doesn't look dry-rotted then carry on.

(I did a Master Cylinder rebuild and cleaned out all the gunk and did the braid install.)

I have a Vance & Hines 4-1 from Z1 Enterprises. You'll need to change the Main Jets...I went from 112 to 117. I must have gotten a great deal because the prices I see now are nowhere near what I paid.


Ed