Running Bad after replacing the timing belt

[steve777]

Hello folks. looking for some advise. i just finished replacing the timing belt on my 2002 ST1100. Bike was running fine prior to replacement. now i have to feed the throttle real slow to get it to higher RPM's. it Bogs if i give it too much throttle to quickly. it runs fine at higher RPM's. it also backfired through the carb a couple of times, which it never did before. im thinking the timing is off.
before i tear it all apart to check it, is there any way to verify proper timing by looking through the inspection holes? Also do these symptoms i described above, sound like a timing issue. i appreciate any advise.

 

[dwalby]

the good news is you can check everything just by removing the valve covers and the bottom crank cover, the bad news is if its off (as it sounds like it probably is) you'll have to pull everything apart again to re-adjust it. Given your story, that's the first step IMO.

 

[bdalameda]

It also sounds like a possible vacuum leak. Did you disconnect any vacuum hoses during you belt replacement? Check all vacuum hoses before you tear into it again.

 

[steve777]

great suggestions im checking it right now. sure would like to find a easy fix. those radiator hoses are a PIA. .... Steve

 

[dwalby]

Hey Steve, how familiar are you with replacing timing belts, and did you turn the engine over by hand to check the timing of everything after installing the new belt? I think that even if you're a tooth off it probably wouldn't run as bad as you describe, because I think people have done that and only noticed it much, much later. If you were off by more than one tooth you probably would have noticed it during the final check.

 

[Mazoc78]

Steve, you did not align the pulleys correctly with respect to the timing belt cogs. I suggest following the repair manual with respect to alignment of the cam position with respect to the valves.

 

[steve777]

i pulled off the crankshaft inspection plate and both cam gear covers. i lined up the TF1 mark on the crank with the index mark on the cover then checked both cam gear index marks. they line up perfectly. my next step is probably check for vacuum leaks, but im pretty sure i didn't mess with any vacuum lines. i think it might be a good idea to do a compression check. when i installed the timing belt i followed the manual exactly, step by step. just crossed my mind what could be the problem. Before i left California, bike ran great. i was at sea level. Now im at 6500 feet. maybe the carbs need adjustments. thanks everyone for your help. i will post my findings. Steve

 

[wjbertrand]

Both left and right sides should not be aligned at the same time. You have to check the left and right sides separately, with the crank in different specific positions for each side.


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[Erdoc48]

Stupid question (maybe)- any chance this is a carb related issue (maybe the carbs weren’t fully seated on the boots and you have an air leak somewhere)? Just a thought especially if you say the timing marks all line up when checked.

 

[steve777]

i did a compression check and all the cylinders were all exactly the same. all within spec. i did notice the plugs were black and smelled like gasoline. so i replaced the plugs. i believe the choke was sticking maybe thats why the plugs smelled like gasoline. i also lubed the choke cables. i had a problem in the past with the choke sticking. so the bike runs perfect now. i think the sticking choke fouled the plug. thanks for everyone help. time to go riding... Steve

 

[RobbieAG]

I'm glad you didn't have to tear into it again.

 

[Bush]

i also lubed the choke cables. i had a problem in the past with the choke sticking. so the bike runs perfect now.

Lubing cables is not a good idea, as it only attracts dirt which will eventually cause it to stick again. Better to keep them clean at both ends.

 

[Jim Van]

Snip ...............

Before i left California, bike ran great. i was at sea level. Now im at 6500 feet. maybe the carbs need adjustments. thanks everyone for your help. i will post my findings. Steve

Logically, it's not a timing belt problem if it ran great after you replaced the timing belt, right ?? I'd try adding some Seafoam besides checking for a vacuum leak.