My GS650 can only go 65mph

[MannyV]

Hello to all the GS fans out there. I have a 1981 GS 650 cammy I've been having issues with top end speed. Off the line is great, and going through the gears is fine. The problem starts when I get to 65mph the bike boggs out. I synced up the carbs which improved performance in the lower gears, but the top end problem didn't change. At this point looking for ideas to fix this.

[tom203]

Another 650 ?- these things keep surfacing everywhere.
Anyways, welcome. Please. please head to this link to find out what you need to do to get your bike running right

http://members.dslextreme.com/users/bikecliff/images/GSR_Greeting.html

wander around Basscliff's site to absorb!

Is this bike new to you? how did you sync carbs? do you have stock factory airbox setup or pods? Falling flat on its face in mid range could be lots of things- not enough fuel, too much air,etc.

[Steve]

Nice to see another 650, but what is a "650 cammy"?

.

[boingk]

Check your air box, filter and carburettor manifold for air leaks. Also replace the filter if dirty. If there and any cracks in the air box or manifold they will need replacing, or at the very least fixing.

You may also want to check your plugs, leads and coils as breaking up under load is often an ignition problem.

- boingk

[Dave_17954]

A quick check is to look at your 2 vent lines on the backside of your carbs. If these are kinked in any way it will give you sluggish performance. I know this from experience and is easy to check.

[Nessism]

Most likely the bike is not running on all four cylinders.

Start up the bike from cold, and very carefully, touch the exhaust header pipes one at a time to see if each one is getting hot. Use a spray bottle with water if necessary to wet each pipe, and/or start pulling off each plug wire cap one at a time. Focus is on finding out which cylinder (s) are not firing.

Some possible reasons include: dirty carbs, burned valves (because someone never adjusted them), no spark, etc.

Time for some maintenance.

I'm in Torrance and can help you, as long as you are committed to the project and want to learn.

Good luck

[storm 64]

My 82 850 Cammy had the same problem. I rebuilt the carborators. And fixed the air leaks... there are guys that rebuild carborators on this site.

[Steve]

My 82 850 Cammy had the same problem.

Now there's an 850 "cammy"?

What the heck is a "cammy"?

.

[storm 64]

You don't know Steve? I figured out of everyone you'd know.

[Nessism]

Maybe a "cammie" is like the "yammie" I read about in another thread?

Add a "swinger" and "carbies" to your "cammie"?

[BigD_83]

Google fu shows this as a cammy:

[MannyV]

Thanks for all the great info and resources, Big D was the closest, I named my bike "Cammy", sorry for the confusion, forgot the quotation marks. tom203 thanks for the link, I've been working on this bike for 6 months, so pretty new. I have pods. Nessism, I work in Torrance. I bought the bike as a project so I want to do it myself, but I'd be a fool to turn down expert advise. Thanks once again, now I have work to do.

[Steve]

I bought the bike as a project so I want to do it myself, but I'd be a fool to turn down expert advise. Thanks once again, now I have work to do.

No problem doing it yourself, but yes, you would be a fool to turn down expert advise from one of the best.

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[Nessism]

Thanks for all the great info and resources, Big D was the closest, I named my bike "Cammy", sorry for the confusion, forgot the quotation marks. tom203 thanks for the link, I've been working on this bike for 6 months, so pretty new. I have pods. Nessism, I work in Torrance. I bought the bike as a project so I want to do it myself, but I'd be a fool to turn down expert advise. Thanks once again, now I have work to do.

You need to rejet the carbs with those pods. Dynajet makes a kit. Failure to rejet will damage the engine. Also, don't forget about other critical maintenance like valve adjustment.

Good luck and keep going...