Won't Start

[Hodado]

Rebuilt carbs on gs650g;fuel does not seem to flow;good spark on all cylinders;bowls are full;what next?? Valve adjustment??

[Dogma]

Rebuilt carbs on gs650g;fuel does not seem to flow;good spark on all cylinders;bowls are full;what next?? Valve adjustment??

Strictly speaking, if you don't know the valves are in spec, they need checked. Said another way, we can't tell you whether or not they're good, because only you can check them. Even if you get the bike started anyway, you need to know these are right before balancing, and before burning valves.

Stock jetting usually requires the airbox and filter to be installed for the bike to start. You didn't mention what state that is in.

Another thing that comes to mind is to make sure the idle adjust screw is turned in far enough. I accidentally turned it the wrong way once, and the bike wouldn't start for anything. Duh.

[tom203]

Rebuilt carbs on gs650g;fuel does not seem to flow;good spark on all cylinders;bowls are full;what next?? Valve adjustment??

Is this bike new to you? Was it running b4 carbs were rebuilt?
Good spark, gas in bowls- Are you using full choke ( must be cold in MICH, cuz it's been freezing in ME). At 75 degrees, my bike insists on FULL choke to come to life- I'd probably have to use a blow torch in 30 degrees.
Sure check valves, but the bike should fire unless all valves are way off.Pull plugs-any sign of gas?

[Hodado]

The bike ran before rebuild;not very well but it did start,it would run on two or three cylinders then gradually run on all four.I will check the idle screw.pulled plugs after cranking and they are dry.and yes cold in Michigan tonite
Thanks

[jwhelan65]

How old is the battery?

[tom203]

The bike ran before rebuild;not very well but it did start,it would run on two or three cylinders then gradually run on all four.I will check the idle screw.pulled plugs after cranking and they are dry.and yes cold in Michigan tonite
Thanks

Dry plugs after some cranking means not enough fuel coming up thru "choke" circuit. Make sure your idle stop screw is not leaving throttle plates open to much ( they should appear just about fully closed), or you won't be pulling fuel up the choke circuit holes.

[spyug]

A couple of things spring to mind and while they have been previously mentioned, they bear mentioning again.

1) Adjust the valves. This is likely the #1 cause of hardstarting. The tutorials are on BassCliff's website.
2) Airbox and filter. These bikes need a certain amount of restriction in the incoming airflow so you need to have a tight airbox and clean filter or good pods. If you are trying to run without them you can substitute some cling film over the carb mouths. Prick a little hole in the center for some air. This should work and get you started.
3) a good charged battery is really needed as you may have to crank for a few minutes at first. If the battery is weak it can run down quickly to the point where there is still enough juice to turn the engine but not enough to fire the coils. If you add a second battery ( a larger automotive or marine battery) you will increase the available cranking amps. Just remember if its in a car don't run the car's engine or you will stand the chance of burning out your bike's electrics.
4) Make sure that the carb "butterflies" are synched and slightly open at rest. If they are jammed shut no gas will be drawn into the engine.

Getting the engine to fire can be a major pain I know but if you attend to the details as suggested, it will go.

Good luck and let us know when you get it running.

Cheers,
Spyug

[Steve]

2) Airbox and filter. These bikes need a certain amount of restriction in the incoming airflow so you need to have a tight airbox and clean filter or good pods. If you are trying to run without them you can substitute some cling film over the carb mouths. Prick a little hole in the center for some air. This should work and get you started.

Even quicker and easier is to fold a shop rag in half, drape it over the carb intakes. Use hose clamps or zip-ties to anchor the rag to the outer carbs, making sure it is taut over the inner carbs. This will make it good enough to go for a test ride, but is not accurate enough to do any jetting checks.

.

[BassCliff]

Hi,

What procedure did you use to rebuild the carbs? Did you squirt some carb cleaner around and install carb kits? Or, did you use an O-ring kit from http://cycleorings.com and follow THIS PROCEDURE?

Check the maintenance lists in your "mega-welcome" for some helpful suggestions.


Thank you for your indulgence,

BassCliff

[Hodado]

BassCliff I followed procedure described although my carbs are not exactly the same as pictured;mine have a "fixed" non removable air screw.I used o rings from cycle o rings.com and purchased K&L rebuild kits from Suzuki dealer.The only other thing I did not replace is the rubber cv boots as they were in good condition, plyable and not cracked anywhere.I am using the stock airbox but am not convinced that it is sealing properly.And yes I have a new battery kept on a battery tender

[BassCliff]

BassCliff I followed procedure described although my carbs are not exactly the same as pictured;mine have a "fixed" non removable air screw...

Hi,

I think this may be the issue. You must remove the cap over the "idle mixture screw" and remove that screw in order to make sure the passage is clean. There's an O-ring that goes on that screw, if I'm not mistaken.





The jets and valve seats in carb kits have a reputation of being of inferior quality. You are better off re-using the stock parts and just replacing the O-rings after the carb bodies have been soaked in a chemical dip (Barryman's carb dip) for up to 24 hours.

One more thing to consider, especially if you used "carb kits". They may come with generic float bowl gaskets. Compare the old ones to the new ones to be sure they look exactly the same. Some are pre-punched and others you will have to punch out certain passages.









It's possible that all of your float bowl gaskets are not exactly the same. One may be different like above. Keep up the good work. You are on the right track.


Thank you for your indulgence,

BassCliff

[Hodado]

Where my air screw should be it looks like a solid casting with a tiny hole in the center, how do I remove that?Is it just a plug? I ran a small piece of wire through it.In the gaskets you picture do I need to punch a hole To make them identical to the ones I replaced? Thanks for your valuble input

[BassCliff]

Hi,

I hate to pick nits, but it's not an "air screw". The older VM carbs have an air screw and a fuel screw to set the idle. The later CV carbs (BS series) have a single "idle mixture screw".

Just screw in a short wood screw into that cap and use pliers to pull it out. Drill a small hole if you have to. Don't go too deep because you can damage the screw itself.

Compare each float bowl gasket. Hopefully you know which old gasket went to which carb. Make sure the new one looks exactly the same as the old one. As stated in the pictures, there should be a perforated punch-out where necessary. You'll notice in the last picture above there are actually two holes that need to be punched out in order to exactly match the OEM gasket.


Thank you for your indulgence,

BassCliff

[Hodado]

Thanks for the information;off come the carbs,again
And yes
Thank you for your indulgence!!

[tom203]

[QUOTE

Compare each float bowl gasket. Hopefully you know which old gasket when to which carb. Make sure the new one looks exactly the same as the old one. As stated in the pictures, there should be a perforated punch-out where necessary. You'll notice in the last picture above there are actually two holes that need to be punched out in order to exactly match the OEM gasket.

BassCliff[/QUOTE]

This Calif ebay seller has repo gaskets- look ok and cheap!

ebay item # 220672241581