Ducati Monster Forum

Moto Board => Tech => Topic started by: He Man on July 28, 2009, 08:20:08 PM

Title: What happens if the timing belts are off by a tooth?
Post by: He Man on July 28, 2009, 08:20:08 PM
So what happens if hte timing is off by a tooth? i think mine is off by a tooth, but im not sure. I idled the bike yesterday for a min or two and it was low, but steady. today i took it out for a spin and it would stall and it isnt running very well. My openers are set, but my closers are still a bit on the loose side.

I took the belts off but cant start the bike, (it died after trying to start it after it died several times). the dot is about 1 tooth i nfront of the mark, i reset it so its half tooth behind hte belt but i cant start it to confirm...


doesnt seem i can get it spot on, but 1/2 behind the mark is the cloest i can get... does the bike run like crap if the timing is off by 1 tooth? the other 2 pullys are spot on.

edit: did some readon, the ECU is apparently very sensitve to voltage, and that could cause the stumbling aside from the belts... i did try to start the bike for a good minute  or 2 yesterday (horizontal plugs werent pluged in!) after having the batt sit for a week doing nohting. its on the charger right now, so when it charges up lets hope it runs better!
Title: Re: What happens if the timing belts are off by a tooth?
Post by: Popeye the Sailor on July 28, 2009, 10:28:00 PM
Timing belts being off by a tooth has been known to cause the dead to rise from the grave. Or worse, it would cause the timing to be off (hence the name). You would run poorly in this case.


Personally I would get it all lined up (you may need a friend to help) and rotate it a coupla dozens times by hand (gently) ensuring there is no extra resistance and making sure the marks all line up. If not, you need to readjust.
Title: Re: What happens if the timing belts are off by a tooth?
Post by: bazz20 on July 29, 2009, 01:38:08 AM
with all your post your not confidant in what your doing, take it  too some one that is and knows what there doing other wise it mite get real expensive 
Title: Re: What happens if the timing belts are off by a tooth?
Post by: Ddan on July 29, 2009, 01:45:57 AM
1 tooth off can put a valve into the piston.  You may not hear or feel anything rotating by hand but you sure will when you start it.

Title: Re: What happens if the timing belts are off by a tooth?
Post by: Armor on July 29, 2009, 08:35:37 AM
How did you set the tension on your belts?
Title: Re: What happens if the timing belts are off by a tooth?
Post by: pennyrobber on July 29, 2009, 10:02:14 AM
Quote from: Dan on July 29, 2009, 01:45:57 AM
1 tooth off can put a valve into the piston.  You may not hear or feel anything rotating by hand but you sure will when you start it.

+1 one tooth off is way off. Your subject line scared me a little.
Title: Re: What happens if the timing belts are off by a tooth?
Post by: lilmonster on July 29, 2009, 06:23:55 PM
Shouldn't cams be locked in place and cam pulleys loosened while tensioning belts?
Title: Re: What happens if the timing belts are off by a tooth?
Post by: He Man on July 29, 2009, 07:23:55 PM
okay, i took the plugs out, pushed the valves open and stuck a strip of polished aluminum in there and the valve edge looks fine and so does the stem. checked all 4 of them too.

I put the belt back on 1 tooth before and fired her up. she idles MUCH smoother now, took her for a spin, shes still pulling enough to loosen up the rear wheel without hickupping through the throttle or backfiring through the rear.

I'll try and write up some sort of FAQ addon specific to the DS1000 engines. After some searching on this forum, it looks like Ivan had some of the same issues i had in trying to figure out where Vertical TDC is, or why wont both rocker arms slide over. Theres just small things about the DS1000 engines that are different from a non Dual Spark that doesnt make much sense if your basing what you are doing on the other 2v videos. Such as the timing hole in the foward cylinder, its actually a slash at 5 oclock not 12. the 5mm key tension doesnt work, you can slide both cams over at once. etc. to find vertical TDC, you put the cam between the finishing intake stroke and starting exahust stroke (around o clock). Youre not suppose to slide the belts off, but instead pull the drive pulley off etc. After watching the videos online, there needs to be a specific one for the DS1000 to address those small things, or at least an addendum.

Bikes back up and running!

oh and how did i tension my belts? i saw a thread where someone said, they had theirs tensioned wit hthe new specs and a 5mm wouldnt fit, but a 3mm would. so i jammed a 3mm in there and tightened it up and called it a day. Im going to go back and use my computer mic to make sure its at a 110hz tomorrow.
Title: Re: What happens if the timing belts are off by a tooth?
Post by: vaclav on August 01, 2009, 06:41:11 PM
I will be looking forward to seeing that.  [thumbsup]
Title: Re: What happens if the timing belts are off by a tooth?
Post by: yotogi on August 04, 2009, 09:32:42 AM
+1  [thumbsup]

I am due for 12K here in a month or so. I really want to do all of this service myself (including valves and belts) your experience with doing your has been informative and I can't wait to see your full writeup.