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Home Come Back Any Time 2010 November 1978 Suzuki GS1000 top speed 70ish

1978 Suzuki GS1000 top speed 70ish

So i recently purchased my first motorcycle a GS1000 and as you are aware this is a big bike and should easily do 100mph but its topping out at 70ish mph, what could be causing this? I did notice it backfires al ot also. I have changed the plugs and cleaned the K&N air filters well i did last night and still have not had a chance to see if that helped, so I will when i get home, but I am looking for suggestions on that issue.

thanks, great site you have here very informative.

Note from Reader:
As you open up the throttle, the gas/air mixture in the carbs changes.  You have 4 carbs and it sounds like you need to get them synchronized.  The backfiring indicates too rich a gas/air mixture.

My Comments:
If you’re running a K&N filter and especially if you are running an aftermarket exhaust, it may just be running way too lean. Do a plug chop. Find a gentle upslope, run the bike in 5th gear, full throttle up the hill. After 10 seconds at full throttle pull in the clutch, kill the engine and coast to a stop. Then pull out the plugs and look at their color. I bet they are white (lean).

Though it could also be a synchronization issue as mentioned by millknee – though you would also have erratic idle if this were the case. It could also be an air leak in the manifolds, or valves that need adjustment.

Nov 27, 2010Evan Fell
1985 Virago 700 Runs on 1 CylinderDown to Mazatlan, Finally!
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