[Tremelune]

I just picked up a '98 916, and while the belts and valves were done 3,000 miles ago, that was 2-3 years ago. I've read that the belts should be done every two years, so I would like to have them done.

My plan was to purchase a set of Bucci belts, new wavy washer and lock nut, ensure the engine has cooled down overnight, and follow this DIY procedure until step 19:

http://www.ducati-upnorth.com/tech/916belts.php

To properly set the tension of the belts, I was going to tune them to 110Hz (within 5Hz) as per this writeup:

http://www.ducati.ms/forums/showthread.php?t=35050


A few things:

1) When I read about the "twist" and "fish hanger" methods of tensioning the belts, I said no, too much room for error, I'm taking it to a shop. The frequency method seems to eliminate the slush. Has this method proven to be tried and true? Have people gone several services with this method, no problem?

2) Neither of these two methods mention exotic tools. With the belts "cleverly" marked with Tip-Ex, do I need to worry about holding the cams in place as long as I line all the marks up properly? Apart from the laptop/mic tension bit, it seems like everything can be done with a set of sockets, crescents, and a torque wrench, yes?

3) I'm a fair wrench, but I've never opened a Ducati engine. If, at any point, I think "Oh shit...I don't want to touch this," I will simply walk the bike into my van and take it to a shop. That said, can anyone point out any "gotchas" they ran into when doing this service themselves?

Any help would be appreciated. I want this bike to go forever.

 

[kaos]

i found ''tuner'' method works well,but when compared to the dealers matheus(?) they were slightly loose(mostly due to my simpler metod over the factory way).i'd also get the part that locks the cams as it makes life easy when replacing the belts (vertical cly cams want to move).and its good practice to mark your old belts and gears and then transfer those marks to the new belts to double check nothing moved

 

[mpaschetto]

A few things:

1) When I read about the "twist" and "fish hanger" methods of tensioning the belts, I said no, too much room for error, I'm taking it to a shop. The frequency method seems to eliminate the slush. Has this method proven to be tried and true? Have people gone several services with this method, no problem?

2) Neither of these two methods mention exotic tools. With the belts "cleverly" marked with Tip-Ex, do I need to worry about holding the cams in place as long as I line all the marks up properly? Apart from the laptop/mic tension bit, it seems like everything can be done with a set of sockets, crescents, and a torque wrench, yes?

3) I'm a fair wrench, but I've never opened a Ducati engine. If, at any point, I think "Oh shit...I don't want to touch this," I will simply walk the bike into my van and take it to a shop. That said, can anyone point out any "gotchas" they ran into when doing this service themselves?

Any help would be appreciated. I want this bike to go forever.

Hi Tremelune,

Welcome to the fray!

If you are a decent wrench, there is no reason to shy away from the belt replacement and tension procedure. I've serviced my belts twice now, it's a nice Saturday afternoon project.

The first time I performed the task, I used the 6MM 'deflection' spec, and (like you) I thought the setting was fairly vague and subjective. Before I did the job the second time, I purchased a Gates 507C sonic tension meter.....setting the tension is easier and more accurate with the meter!

In both cases, I didn't use the special tool to hold the vertical cylinder cams in place....it wasn't necessary. Just be sure to mark your old belts before removal, and transfer the marks to the new belts before installation. I feel that it makes the reassembly procedure a little bit easier.

Lastly, when tensioning the belts, be sure to rotate the eccentric tensioners in the COUNTER clockwise direction to tension the belts!



Please post up if you have any other questions or concerns,

Mike

 

[mbevans]

Yes, I aggree. Buy that aluminum plate that holds the cams in time with each another. I went without for many years and it was a pain, they're $25.00 on flea-bay.

Setting tension is a age old issue for many. I am most likely "old-school" but I've used the old allen wrench method forever, no broken belts, no worn out bearings for the idler pullies. And I've bounced the 996 off the rev limiter far more times than I can remember.

Just because "someone" checked your valves 3k miles ago, check them again, check the rockers closely, afterall this is your new Ducati!

Treat her well and she will, ah you know....

Cheers,
Mark

 

[Kramer749]

I was wondering if the Gates 507C sonic tension meter will work with 749 999 and if so at what hz. I was told using a .005 feeler gauge will work too. The new design of the pulley tensioner with the lip on it its harder to check using that method. I just got my bike back from the dealer for the 6000 mile sevice and I never want to take it back ever again. $900 and I did most of the work myself. Granted the bike runs great. I can't stand someone else touching my bike. I can turn a wrench on just about everything on this bike, but getting the warning light off the display. When it comes to the dealer scheduled maintenance crap it think its a money making gag. If you guys have any more advice about belt changes, valve adjustments, and tools needed. Im all ears /eyes.

 

[Tremelune]

Just because "someone" checked your valves 3k miles ago, check them again, check the rockers closely, afterall this is your new Ducati!

Heh, indeed. The 12k was done at a respected shop around here, but...I am still waiting for that piece of paper from the previous owner!

Kramer, check the second link I posted. It discusses using a laptop and a microphone to measure tension sonically. A glorified guitar tuner.

 

[nine16]

I was in a similar position as you when I bought my 748. I didn't replace the belts right away, but I also didn't feel comfortable doing trackdays or really wringing it out until the service was done.

The cam holder tool is cheap enough--I've even seem them for about $16. When peforming the service this spring, we used the laptop/microphone method to 110Hz. Worked great. I hear there is even an iPhone app you can use now.

 

[mpaschetto]

I was wondering if the Gates 507C sonic tension meter will work with 749 999 and if so at what hz.

Yep, it will most certainly work on your bike.

The 507C is an industrial tool, and will work on a host of different belt styles and widths. The Northeast Gates Sales Manager offered the item to me at cost after he called on me at the office.....I can't remember how the conversation veered off to motorcycles. It sure seemed easier than assembling the laptop based solution, so I bought it.

Mike

 

[John]

I was wondering if the Gates 507C sonic tension meter will work with 749 999 and if so at what hz. I was told using a .005 feeler gauge will work too. The new design of the pulley tensioner with the lip on it its harder to check using that method. I just got my bike back from the dealer for the 6000 mile sevice and I never want to take it back ever again. $900 and I did most of the work myself. Granted the bike runs great. I can't stand someone else touching my bike. I can turn a wrench on just about everything on this bike, but getting the warning light off the display. When it comes to the dealer scheduled maintenance crap it think its a money making gag. If you guys have any more advice about belt changes, valve adjustments, and tools needed. Im all ears /eyes.

I learned to appreciate that it does take time no matter who does the work to conduct the service intervals. It took forever it seems to dismantle my 916 in order to access the valves, then you had to work in minature to check clearances through tiny openings. With the 999 access was much easier and the working area was hugh since the whole valve cover comes off to expose the valves, shims, etc. Nevertheless, it takes time and I would say the process is labor intensive so I understand now why it costs so much to conduct a service. Yes we can do valve clearances and change the belts, but there are other matters we are ill equipped to do and that may be why your bike is running so good at this time. I kind of had the idea of doing the service interval which included the valves, belts (if needed) and then let the dealer do the rest like carb sync, etc. I haven't done that yet but its a thought.

A trusting dealer is the key I suppose. There has been volumes written about that around here.


Also, in regards to the belts, just make sure the you have the timing marks lined up correctly prior to removal and install.

 

[Kramer749]

Thanks for the advice guys. Im not trying to down the duc shops out there or anything. I understand they're trying to keep there doors open and paying off that 12,000 dollar DSS system.

 

[otter1]

Threadjack

Sweet SSSA on your 749 Kramer749! What model is it off? Thanks.

 

[Kramer749]

Swingarm is off a 2002 998
wheel is off a 2008 1098

 

[Tremelune]

Okay, I've got the bike apart. I lined up all the timing marks on the belts, and marked the belts. Step 11 says to "fine tune the alignment" by lining up the marks in the window on the left side of the bike before removing the belts.

When the two marks in the window are aligned, the timing marks on the belts and cams don't line up with anything. Is this a problem or am I thinking too much? Once the belts are marked, why move the motor? In fact, since I know how to mark the new belts by counting teeth, what difference does all this TDC make, since I know I must simply line up the marks on the belt with the marks on the cams?

 

[DukeDesmo]

what difference does all this TDC make, since I know I must simply line up the marks on the belt with the marks on the cams?

When the belt pulleys (yellow dots/lines on crankcases) are all at the correct position then the belts are correctly positioned and at that point the horizontal piston is at TDC.

You should check the belt tension for each cylinder when the piston is at TDC. The flywheel marks indicate the TDC for each cylinder.

 

[Tremelune]

Walk me through this a bit...

When the belt pulleys (yellow dots/lines on crankcases) are all at the correct position then the belts are correctly positioned and at that point the horizontal piston is at TDC.

Okay, all the marks are lined up. The H piston is TDC, but the V piston is not?

You should check the belt tension for each cylinder when the piston is at TDC. The flywheel marks indicate the TDC for each cylinder.

The flywheel has the mark that I'm looking for through the window, right? The flywheel indicates TDC for the V piston or what? It certainly doesn't coincide with the TDC markings on the cam pulleys/case.

 

[Abandon42S]

The crankcase dot and output pulley dot should line up to set the H-cyl at TDC as described previously. The flywheel should also show a mark lined up in the window as shown in a picture before. Set the H-cyl belt-tension. Then rotate the engine to get the V-cyl at TDC. Another mark should line up in the window. (I usually put a long zip-tie in the V-cyl just to confirm the V-cyl position). The output pulley will not be aligned with the crankcase mark. Set the tension for the V-cyl. Done.

 

[Tremelune]

The crankcase dot and output pulley dot should line up to set the H-cyl at TDC as described previously. The flywheel should also show a mark lined up in the window as shown in a picture before.

Two things seem inconsistent:

1) When one cylinder is at TDC--ie, all of the marks on the pulleys line up with all of the crankcase marks--the other cylinder is lined up as well. According to the marks on the pulleys and crankcase, both cylinders are at TDC at the same time.

2) When the two cylinders are at TDC, there is no flywheel dot visible. When a flywheel dot is lined up with the window arrow, no cylinders are ever at TDC (according to the pulley/case marks). When I move the flywheel by turning the rear wheel with the bike in top gear, the dots sometimes fly by the window. I can't even be sure there are two dots.

I'm gonna try and read up on general timing for these motors. What am I not understanding about the relationship between the flywheel marks and the pulley/crank marks? I wish I had a shop manual, but the PDF I have seems to be corrupt.

Pulley = Toothed wheel
Roller = Smooth wheel

 

[Tremelune]

As an aside, I haven't taken the old belts off yet. According to the DIY, I'm supposed to get all this timing stuff done first, though I don't know why.

 

[Tremelune]

Alright, I think, after reading things over, I have it figured out:

1) When all marks on the horizontal and vertical pulleys line up with all of the crankcase marks, only the horizontal piston is at top dead center. This is where you want to be when you replace the belts and adjust tension for the horizontal belt.

2) When the arrow on the left-side window is pointing at the mark on the flywheel, the vertical cylinder is at top dead center, and the marks on the pulleys are probably not aligned with anything. This is where you want to be when you adjust tension for the horizontal cam belt.

Do I have this correct?

 

[Tremelune]

Perhaps not. From this page:

When you find this mark, only one
of the cylinders is at TDC- you'll need to check the clearances of
each cylinder's valves to find out which one. When you spin it
around again and line them up, the other cylinder is at TDC. At
TDC, the valves are both closed and the piston is at the top of the
cylinder. Another helpful aid is that the horizontal cylinder has a
dot on the cam spinning gear that lines up with a raised nub on the
black rubber portion on the horizontal head when it is at TDC. One
more thing to throw you off- there are two TDC's per cycle on a 4
stroke engine, and the one at the end of the compression stroke is
the one you should measure on. The tick mark on the horizontal
cylinder cam gear that I was talking about may seem like it is at
TDC, but may actually be at the wrong TDC.

Is this page, which discusses 2-valve adjustment, relevant to adjusting timing belts on my 916? I've read elsewhere that you want to adjust at TDC of the compression stroke as well...I think at this point, I may very well do another writeup, built off of all these writeups...