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Discussion Starter #1
Guys, I need your help. I finally got the harmonic tension thing working on the computer, so I set the bike to TDC compression on the horizontal cylinder. Lined up the timing marks on the cam pulleys and layshaft. Pulled the old belts, replaced with new. Tension right at spec. Turn motor over using engine turning tool and it got hung up. Seems stuck, and I am not going to force it. I am guessing in spite of my best efforts I got something out of time? Bike has just 600 miles on it and ran perfectly before I tackled this project. I think I might be out of my league on this one, any help appreciated.
Al
 

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it is likely the vertical cly is out of time since the timming marks for the vc do not = tdc. the upper pully has some spring load on it from the closer assit spring and can move when trying to fit the belt over the pully. you may need to remove the valve covers and belts and turn the cams to the get the valves in the closed tdc position. from there you can set about relocating the crank and valve setup.
 

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Don't force it. Did you adjust you're valves also? I would remove the belts and try again. Good luck.
 

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i think if the valve covers and belts are off and you turn the cams by hand to the tdc position it would be a good time to check the clearance, even if the bike has only 600 miles on it.
 

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I'm sure someoine else will beat me to this, but I will go get my Dr.Desmo book and look it up. Good job not forcing it. You might have bent a valve had you done.
 

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Discussion Starter #6
Thanks for all the replies. I took the new belts off and am thinking I need to line everything up again and see if the thing turns. How do I start from square one and give it another shot? At what position do the crank/cams/valves need to be for everything to get squared away?
 

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Thanks for all the replies. I took the new belts off and am thinking I need to line everything up again and see if the thing turns. How do I start from square one and give it another shot? At what position do the crank/cams/valves need to be for everything to get squared away?
What book are you working from or are you working without and why were you doing this work at 600 Mls anyway ?
(LT Snyder is a good place to start)
It appears you may have delved in a little too deep on the "Get to know my Ducati" experience but wish you well with it.
 

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Discussion Starter #8
I have LT's book and the shop manual. Why do this at 600 miles? Well I went around and around with this notion but it seemed the concensus was to go by the years on the bike rather than mileage. I am no mechanic by any means, but this can't be that hard, right? My fzr400 race bike has 16 valves that require the cams to be removed for an adjustment and I have managed to get through that process okay. But I must admit I am losing confidence after this seemingly simple task.
 

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i am an st2 person but the set up should be the same. the st2 has timming marks on the belt pulleys and on the flywheel, on the other side off the bike there should be a sight window in the case. with the bellts and valve covers off
1. turn the cams by hand till the valves are in the closed postion and there should be clearance between the valve stem and rocker arms, both intakes and exhaust. this is the = of the valves being @ tdc. you can do this either clockwise or anti cw, path of least resistance so to speak. once both sets of valves are at the closed position you can now rotate the crank without a piston and valve interferance.
2. now you are free to turn the crank and line up the flywheel marks and check which piston is @ tdc. on the st2 the horz cly is at tdc, the vertical is not. i have not looked into an actual st3 so i can not advise beyond this point.
 

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on second thought you could bring one cly to tdc via the flywheel marks and see which cyl has its piston "up". then you could make some marks, attach the belt and rough tension it. then turn the motor over by hand at least 360 degrees. spin free, now bring it back to tdc via the marks, remove the belt and do the same for the other cly. now you should be able to put the inner belt on @ tdc. then rotate the engine by hand to get the outside belt cly at tdc and put that belt on. now you can rotate the engine by hand once more, spin free, set the belt tension and button it up. it might be the long way around but it should be safe.
 

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Your original post mentioned that the bike has 600 Mls on it , or am I misreading something.
Be cautious of advice from those who do not know the ST3 because it is a new design , differrent cam lay-out etc) and as such may have different requirements.
Not saying you cant do it but was concerned at how much information you had to hand as all of the necessary proceddures / marks should all be clearly set out in the manuals.
 

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Hey Al!

I'm off today and would be happy to come up. I have never "done desmo" but I have changed many timing belts. Maybe another pair of eyes and hands could be of assistance. Say the word...

Michael
 

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Discussion Starter #14
Thanks for the offer Michael, I got to your reply too late. I am either going to take it to Hansen's or possibly take the advice of a couple of the guys and give it one more whirl.
Al
 

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Discussion Starter #15
Problem Solved

The resolution was to take it to the dealer (Hansen's in Medford, OR) and have them put the belt on. They charged just over $100 in labor. I consider it a bargain considering the potential cost of further mishaps and was well treated by the dealership. They checked the database for outstanding recalls and there were none. So all is well at the moment, now I just have to get the bodywork on and maybe in the next week or so actually go for a ride! Thanks again to all who responded to my request for help.
Al
 

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Al:

Thanks for posting about your positive experience at Hansen's. I don't hear too much about those guys and I've been wondering how they are doing.

If you still have the belt covers off, perhaps you could snap a photo of the cam drive gear while the pistons are at TDC. You can use this photo for reference when you do your valve adjustment so you'll know how the cams should be positioned with respect to the drive gear. I usually put a mark on the cam gears before I pull the belts to use as a reference.

Belts are cheap. I keep my belts fresh also, regardless of the milage. I also take advantage of the long Oregon winters and do all my maint in December or January so that the bikes are fresh for summer.

Good Job!
 

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Al:

Thanks for posting about your positive experience at Hansen's. I don't hear too much about those guys and I've been wondering how they are doing.
I didn't know they handled Ducatis until just recently but Craig Hansen has been a long time BMW guru, at least back a few decades ago. I've been out of the loop since but if he followed a similar path with the Ducs he's in good shape.
 

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It would have been good to have learned what it was that you did wrong, other than "should've sent it to the dealer".

This way I/we could've learned from your mistake:D.

Oh well, I guess I'll just mark the cams/belt/driver when time comes to change my own belts (end of this year I think).
 

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Discussion Starter #20
Well here is my recollection of what happened. It will be convoluted of course.The timing marks were all lined up prior to putting the new belts on. Once I put the belts on, all was good as far and lining up the marks.. but the screwup factor was the lack of tension on the belt. Since I couldn't really see the teeth on the layshaft. What I didn't know was that I was off by a couple of teeth on the layshaft, and when the slack was taken up, the cams rotated out of place by a couple of teeth. I saw that and ignored it (late at night, tired etc). Next I rotated the engine by hand at the crank. It only went about 180 degrees(?) before I encountered unusual resistance and felt a sort of metallic sound. Obviously I stopped there. I pulled off the belts and tried to rotate the cams by hand back to the timing mark. That was another mistake because now they were further out of whack. Which was when this thread began and thankfully ended happily although with much initial frustration. So if I attempt this again, the key will be to make sure it is the tensioner side of the belt that is loose, not the fixed side. I hope that helps someone. To be honest, at this point I think that spending a couple of hundred bucks every other year to get this done at Hansen's is money well spent. At least for me.
Al
 
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