bike runs but poorly

phil823 · 07-10-2009, 02:35 PM

Bike Information:
1983 GR650 "tempter"
2 cyclinder, 4 stroke, DOHC, Inline engine
16k Miles
Top end rebuilt, carbs rebuilt, valve clearances stock? (have not looked at them they say adjusting isnt needed till 25k).
foam UNI filters installed
New Nology Coils installed
All else stock
i had these problems before the new Filters and Coils.
bike starts no problem.
bike will accelerate to 80mph (top is 102. and im a big guy so thats ok i guess)
bike is getting 25mpg!!
Issues!:

right plug fouls VERY quick, like 5 min or so.
after checking it after a run of higher speed, 45+ MPH, the top turns a tannish but everything else is still sooty black.

only getting 25mpg! should be getting 40!

backfires through carb, but i believe thats cause the left is running a little lean.

bike has an off idle. the right side sounds like its skipping or rushing to catchup up every few seconds. im guessing due to fouled plugs, spark is weaker.

anything past 1/2 throttle bike RPM goes up but there is no acceleration. can this be caused by running to lean possibly?

the bike has had these issues forawhile, and i thought new coils would fix it, but it did not. any ideas?

im stumped.

on the 21st a local shop is putting my bike on the DYNO to get the lean issues all fixed. is there anything else i should look at or tell them to look at? im stumped and i just want a running bike

slumlord · 07-10-2009, 04:01 PM

does this shop do carb synching?

phil823 · 07-11-2009, 12:46 PM

yes, but my carbs only have 1 vacuum port that the old petcock used to use.

ballardchris84 · 07-28-2009, 09:44 PM

the top end was rebuilt? were the valves replaced? if not, that could be the problem.
did the shop get your problems all fixed or find a cause?

phil823 · 07-29-2009, 04:17 AM

looked into the problem furthur. i leaned the right side out so far that it was carb backfiring.

it ends up it was oil fouling!

i got a valve job and new piston rings.

atm im working on shimming. after the work the sizes are quite a bit different.

07-10-2009, 02:35 PM	#1
phil823 Verified Join Date: Mar 2009 Posts: 35	bike runs but poorly Bike Information: 1983 GR650 "tempter" 2 cyclinder, 4 stroke, DOHC, Inline engine 16k Miles Top end rebuilt, carbs rebuilt, valve clearances stock? (have not looked at them they say adjusting isnt needed till 25k). foam UNI filters installed New Nology Coils installed All else stock i had these problems before the new Filters and Coils. bike starts no problem. bike will accelerate to 80mph (top is 102. and im a big guy so thats ok i guess) bike is getting 25mpg!! Issues!: right plug fouls VERY quick, like 5 min or so. after checking it after a run of higher speed, 45+ MPH, the top turns a tannish but everything else is still sooty black. only getting 25mpg! should be getting 40! backfires through carb, but i believe thats cause the left is running a little lean. bike has an off idle. the right side sounds like its skipping or rushing to catchup up every few seconds. im guessing due to fouled plugs, spark is weaker. anything past 1/2 throttle bike RPM goes up but there is no acceleration. can this be caused by running to lean possibly? the bike has had these issues forawhile, and i thought new coils would fix it, but it did not. any ideas? im stumped. on the 21st a local shop is putting my bike on the DYNO to get the lean issues all fixed. is there anything else i should look at or tell them to look at? im stumped and i just want a running bike

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

07-10-2009, 04:01 PM	#2
slumlord Senior Member Join Date: Dec 2008 Posts: 1,533	does this shop do carb synching?

07-11-2009, 12:46 PM	#3
phil823 Verified Join Date: Mar 2009 Posts: 35	yes, but my carbs only have 1 vacuum port that the old petcock used to use.

07-28-2009, 09:44 PM	#4
ballardchris84 Newbie Join Date: Jul 2009 Posts: 5	the top end was rebuilt? were the valves replaced? if not, that could be the problem. did the shop get your problems all fixed or find a cause?

07-29-2009, 04:17 AM	#5
phil823 Verified Join Date: Mar 2009 Posts: 35	looked into the problem furthur. i leaned the right side out so far that it was carb backfiring. it ends up it was oil fouling! i got a valve job and new piston rings. atm im working on shimming. after the work the sizes are quite a bit different.