Timing off

[Basic]

Have just changed the belt and pullies and got a few remarks:
Started the work on my '92 because I did not know whether it had been done in the past.
This is how I found the old belt on the right cam:

With the other markings in position, this was one tooth off. Since the belt still looked like new and there was no length difference with the new one, I can only assume that a PO did replace it and it went wrong.
Since it is my first ST1100, I did not notice when driving.
When putting the belt on it can easily be misplaced, so the lesson from this is that one has to re-check the posittions when the belt is on and on tension.

Also, for checking the positions with the plastic cover off, I found it easier to check in between, using a piece of cardboard with the timing marking on it. (Only a few minutes work to make such cardboard, drawing the lines over from the plastic cover.)

Another warning might be in place here: Though it is advisable anyway, I had to pull the clutch cover for replacing the springs. To do that, the right downpipes need to be removed. Though looking nice from outside, they snapped instandly at the rear end.
If you have to remove these, be very careful!

Can't be 100% sure that the timing misplacement was the cause since I also did some other works, but the bike now has a lot more power at lower rpm.

Regards, Rob

 

[ST1100Y]

When putting the belt on it can easily be misplaced, so the lesson from this is that one has to re-check the posittions when the belt is on and on tension.

Correct, I always rotate the engine through twice by hand (plugs removed, ratchet attached to crank-pulley) to recheck after installing the T-belt...
Methinks you might want to check your carb syncing after that timing error has been fixed...

 

[Basic]

Yes, checked carb sync and it needed only slight adjustment. Thanks for thinking along!
The bike has been using a bit of oil (1 liter in 10k km), so, before work on timing belt, I drained some oil, added two bottles of Fort? Motorflush and let it run idle for 45 min.
After that all oil drained, filter replaced and new oil in.
Also I changed to iridium spark plugs. The broken exhaust is temporarely fixed, so airflow through the pipe might not be optimal.
Because of other reports here that the timing being off one tooth may be hardly noticable and the other works I did, I can't say that fixing it is the cause for my performance improvement.

 

[ST1100Y]

Also I changed to iridium spark plugs.

Gave them a try a couple of years ago, but was not convinced... my '00 did show slight vibes with them installed, back to the regular NGK-R types and the vibes vanished...
Also firing up was a bit 'harder' (read: required noticeable more rotations of the starter motor), whilst with the standard plugs its like turning on your VCR or sat-receiver...

One tooth off is not an issue for the engine (it is an interference type though...), just odd performance, mileage decrease maybe...
It will pull better and smoother now with proper timing established.
We once had an ST in the w/shop with the belt being two notches off, and then it obviously had been 'corrected' by messing up the positions of both camshafts to the reduction gear pulley on that bank... that poor engine idled like a wet dog shaking off, the carb sync was totally odd... and now figure out what's wrong with that engine... took a few moments of some serious thinking though... not to mention the fancy language sounding once it got obvious... :lol:
There was quite some more 'botch' to be found on this mount... so instead of a simple MOT inspection, it then took +5 hours of serious wrenching to fix all that $h!t, forks out, rad out, the whole program... so just don't get your services done in a 'backyard workshop'... ;-)