Ajusted valves = bike starts and dies

[Rameses]

well instead of rotating the crank i rotated the cam. bike ran for a bit longer but still died.
should i have set the bike to vert tdc using the sight window. and then rotated the crank with the belt off?

in my head it makes sense that rotating the vert. cam at horizontal tdc would do the same thing as rotating the crank at vert. tdc.

uh. my brain...

That doesn't work.

You have to rotate the crank.

Rotating the cam 180 degrees and then putting the belt back on puts everything back the same as it was.

Rotating the crank 360 degrees and then putting the belt back on sets the spark timing to where it needs to be relative to the cams.



edit:  Well, I guess you could do it by rotating the cam, but you would need to rotate it 180 degrees and then wouldn't have a timing mark to line it up with and would risk being off by a tooth on the belt.  Not a risk I would want to take.

[Rameses]

FYI if you take the spark plugs out you can feel a rush of air coming out on the compression stroke and you can look through it to make sure.

That's only if the belts are on.

And if the belts are on, but timed wrong by 180 degrees, you'll feel the air coming out like it's the compression stroke when it should actually be the exhaust stroke.

[vboulderer]

That's only if the belts are on.

And if the belts are on, but timed wrong by 180 degrees, you'll feel the air coming out like it's the compression stroke when it should actually be the exhaust stroke.

Rameses you're kick'n A$$ bro thanks for the info.

problem is if i set the crank to tdc according to the marks  on the pulley and crank case, take the belt off the vert. cylinder I can't rotate the crank fully.

[Rameses]

Rameses you're kick'n A$$ bro thanks for the info.

problem is if i set the crank to tdc according to the marks  on the pulley and crank case, take the belt off the vert. cylinder I can't rotate the crank fully.

You'll have to take the belt off, rotate the vert cam to where both valves are closed, turn the crank 360 degrees, turn the cam back to where it lines up with the timing mark and then put the belt back on.

[DucHead]

Make sure your Throttle Position Sensor is plugged in.

Don't ask how I know to suggest that.   

THAT was a classic! 

[uclabiker06]

Wow, I would have imagined this mistake would have the same effect as a broken belt...glad things worked out and things didn't bang into each other.

[vboulderer]

Ok vert. cyl done. Bike starts runs very poorly for much longer (30+ sec.) then begins to choke out.

I suppose i'll try the horizontal cyl. one more time to see if that one was good and just the vert. was off.

either way thanks to those who've helped. I'm obviously new to the ducati community but am really impressed by the
support.

i'll post an update in a few min. 

[Rameses]

i'll post an update in a few min. 

Yeah, let us know how it goes.

If that's not it, we'll help you troubleshoot.

[Rameses]

THAT was a classic! 

[vboulderer]

well unfortunately that wasn't it... bike ran worse after redoing the horizontal.
A bit soul destroying honestly. I've been working on this for the better part of 3 days.
any ideas.

I may be pushing this italian paperweight  onto the trailer tomorrow morning. the dealer's going to have a field day

[Rameses]

well unfortunately that wasn't it... bike ran worse after redoing the horizontal.
A bit soul destroying honestly. I've been working on this for the better part of 3 days.
any ideas.

I may be pushing this italian paperweight  onto the trailer tomorrow morning. the dealer's going to have a field day

Well, first thing I'd do is rotate the crank relative to the horizontal cam again, since that seems to be the best combination for how it runs.

Then check over all of the vacuum and electrical connections again like Howie suggested earlier.

[Rameses]

One more thing...

After you change the horizontal cylinder back, start it and let us know how it runs at various rpm.

For example, if you give it a lot of gas and get it up to ~6,000 rpm does it smooth out at all?

[Desmo Demon]

I just read all the other posts.....

I can't rotate the crank fully.

This should be taken as a sign to STOP.....not being able to rotate the crank with the spark plugs out and the belts on is a bad sign.......it often means that a valve is tapping a piston or at least one closer shim is too tight and is giving resistance to cam rotation.

Ok vert. cyl done. Bike starts runs very poorly for much longer (30+ sec.) then begins to choke out.

If it wasn't for all the cam flip-flopping that has been done, I'd say this is a fuel/carb/injection issue.

I may be pushing this italian paperweight  onto the trailer tomorrow morning. the dealer's going to have a field day

Unfortunately, this may be the thing to do. I don't have a manual with me and don't remember how to tell when the crank is on the compression stroke for the horizontal cylinder. I believe a repair manual showing a complete engine rebuild explains how to align the cams with the flywheel markings.


For future reference if anyone stumbles across this thread later on I will explain how I do my valve adjustments and belt changes:

1) Get the horizontal cylinder on TDC compression (you should be able to easily rotate the opening shims with your fingers. I believe that if you cannot rotate the exhaust opening shims, it is on the exhaust stroke).
2) Do your valve check/adjustment
3) If you changed a closing shim and want to check if it is too tight creating binding on the rocker from the cam shaft do steps 4-8
4) Mark the edge of horizontal timing belt with a silver or gold Sharpie pen
5) Loosen the adjustable belt tensioner
6) Only remove the section of belt that is on the cam (I try to leave the belt on the drive pulley and do this with a clothes pin holding the two side of the belt a couple inches away from the drive pulley)
7) With the belt off the pulley, gently rotate the cam and feel for tightness. If OK,
8 ) Reposition the cam shaft and reinstall the timing belt, but don't readjust the belt tension
9) If you are done with the horizontal head, with the timing belt reinstalled, rotate the crank until TDC compression is found on the vertical head.
10) Do steps 1-8
11) If you are done with the vertical head, I always rotate back to TDC compression for the horizontal cylinder. This is because all of the fractory timing marks align (except Testestretta engines).
12) Remove both belts
13) Install new belts (on 2V engines, the vertical cam may partially rotate. 4V engines may have the exhaust cam rotate, so these cams will need to be rotated back into position if they shifted)
14) Adjust belt tension for the horizontal
15) Rotate to TDC compression for the vertical
16) Adjust belt tension for the vertical
17) Rotate through another cycle or two while checking the timing marks at TDC of the horizontal. If you get to a point where the crank will not continue to move, you may have a cam a couple of teeth off and is causing the piston to hit a valve. This is most likely is when installing the new belts, the vertical cam partially rotated and was not rolled back to the proper position before the new belt was installed.

There is a concern that if the belt tension is not set with the piston at TDC compression, there may be additional tension added to the belt from a cam shaft being partially loaded, which would lead to setting incorrect belt tension.

By never rotating the crank while a belt is off, you will never run the risk of having any timing issues.

If any of this appears incorrect, please let me know. It's fairly early and I'm going by memory on this.

[vboulderer]

Nice run down. 
just to clarify.
1. with belts on i could rotate the crank freely by hand with no issues.

2. While doing the valve check with the belts off I never rotated the crank just the cams.

3. The bike is already at the dealer... i'll let you all know how things turn out when i get it back.

Thanks again for all the help guys.

cheers

[EEL]

Good lord...Coming into this tread a bit late since its already at the dealer but I hope this is a lesson to all...

MARK YOUR FRIGGIN CAM GEARS....They are DOTS on the vertical and horizontal timing belt covers. Get TDC on VERTICAL cylinder and MARK the cam with respect to the dots.

Its takes all of about 30 seconds to do..

Timing should not be this difficult. You can set timing with a maximum of 2 points on the 620. The notch on the top part of the clutch cover and the flywheel dot. If you see the dot in the the flywheel AND the dot on the double pulley matches the notch in the clutch, you're at TDC for the horizontal cylinder. Then you just instal the belts and align the dots on the cams with the dots on the timing belt covers and put the belts on.Theres no need for 17 Point thesis on this.

Keep things simple...