Ducati Monster Forum

Moto Board => Tech => Topic started by: He Man on June 07, 2012, 07:53:26 PM

Title: Damage assessment: Flywheel falling off
Post by: He Man on June 07, 2012, 07:53:26 PM
I am trying to assess the amount of damage i can possibly be dealing with after my flywheel came off.

shipping to NYC vs shipping to colorado is a matter of $100 bucks....

If the flywheel comes off, aside from the timing being all wacked out, what else can go wrong?

is bent valves and damaged piston the worst thing that can happen?

Can the timing on the belt side of the motor be messed up?
Title: Re: Damage assessment: Flywheel falling off
Post by: suzyj on June 08, 2012, 03:13:02 PM
Quote from: He Man on June 07, 2012, 07:53:26 PM
I am trying to assess the amount of damage i can possibly be dealing with after my flywheel came off.

shipping to NYC vs shipping to colorado is a matter of $100 bucks....

If the flywheel comes off, aside from the timing being all wacked out, what else can go wrong?

is bent valves and damaged piston the worst thing that can happen?

Can the timing on the belt side of the motor be messed up?

I can't see how the flywheel could affect the belts or cam timing - I'd think the stator is likely to be damaged, and perhaps the side case on that side.
Title: Re: Damage assessment: Flywheel falling off
Post by: He Man on June 08, 2012, 05:22:09 PM
if the flywheel comes off, the smaller timing gear can come off and then the valves would stop working bu the pistons would still turn.
Title: Re: Damage assessment: Flywheel falling off
Post by: Howie on June 08, 2012, 08:31:46 PM
Your bike is the very first one I know of that skipped timing when the flywheel came loose.  You will need to pull the heads to ascertain the damage.
Title: Re: Damage assessment: Flywheel falling off
Post by: He Man on June 08, 2012, 08:59:14 PM
would a compression test or a leakdown test suffice?
Title: Re: Damage assessment: Flywheel falling off
Post by: Ddan on June 09, 2012, 02:08:14 AM
A good leakdown test would mean you're probably OK, but if you're certain you skipped timing and the motor ran at all, you really need to pull the heads.
Title: Re: Damage assessment: Flywheel falling off
Post by: scduc on June 09, 2012, 04:57:13 PM
After just looking at my service manual, I just dont understand how the gears on the left side would affect the timing on the right which control the valves. The only small gears are for the starter. I know that when I took the left side apart, there was a mark on the flywheel that matched a mark on the starter driven gear. My guess is that those 2 need to be aligned, but my concern would be did the flywheel come off while driving? In which case I dont even want to see the pics of what it did to the case and cover. I know from experience that the shifter forks are sensitive. A 2 to 3 lbs mass traveling at 4k RPM, not pretty. After re-reading the OP, I'm now confused. "If" the flywheel comes off. You do not know, is this just speculation? And what does shipping have to do with the flywheel coming or not coming off?  Need more info.
Title: Re: Damage assessment: Flywheel falling off
Post by: brad black on June 09, 2012, 06:33:22 PM
do you mean the flywheel came loose?  it can't come off unless the cover is not there.  remove the cover and have a look. for a timing gear to come off its key the flywheel would have to move off15mm or more, which it can't with the cover on.
Title: Re: Damage assessment: Flywheel falling off
Post by: He Man on June 09, 2012, 06:36:27 PM
I should rephrase.

the retaining nut came off the crankshaft and the flywheel ate part of my left side case. The smaller timing gear came must of came off the layshaft or the woodruff key somehow disengaged because the timing gear (which functions with the ignition pickup to give the spark) was not spinning, but the pistons were.

if the damage is too great, it is not worth shipping it to colorado (where i am currently) and would be cheaper to ship it home (NYC) so i can work on it when i have time.

Im working 65-90 hours a week right now so time off, is spent relaxing!
Title: Re: Damage assessment: Flywheel falling off
Post by: brad black on June 09, 2012, 10:22:06 PM
ok. 

if it has bent valves you won't be able to turn the cams.

if cams turn, refit the timing gear in the correct spot, fit the flywheel and tighten the nut and give it a comp test.

no one can answer these questions without seeing the engine.
Title: Re: Damage assessment: Flywheel falling off
Post by: cokey on June 09, 2012, 11:25:56 PM
For those not in the know..

http://www.ducatimonsterforum.org/index.php?topic=56816.105 (http://www.ducatimonsterforum.org/index.php?topic=56816.105)

Goodluck man..
Title: Re: Damage assessment: Flywheel falling off
Post by: He Man on June 10, 2012, 02:45:38 PM
Before i left the bike, i refitted the timing gears. There was spark. There was also a tick when i turned the engin over. But the motor would not attempt to pickup the spark. I removed the plugs and tried to see if i flooded fhe engin ( the plugs were not wet with fuel) I tried starting again. No joy.
Title: Re: Damage assessment: Flywheel falling off
Post by: He Man on June 10, 2012, 05:04:45 PM
Quote from: brad black on June 09, 2012, 06:33:22 PM
do you mean the flywheel came loose?  it can't come off unless the cover is not there.  remove the cover and have a look. for a timing gear to come off its key the flywheel would have to move off15mm or more, which it can't with the cover on.

Since the woodruf key can move around, is it possible that the small gear backed off enough so the key cant engage the gear? I physically observed the timing gear. Ot spin but the flywheel was spinning. So the flywheel came loose enough to allow the small timing gear to not engage.

Title: Re: Damage assessment: Flywheel falling off
Post by: He Man on July 17, 2012, 10:15:45 PM
does this look like its in the right order?

(http://www.kuixihe.com/gallery3/var/resizes/Trips/Move-to-Colorado/P1020664.JPG?m=1338227566)
Title: Re: Damage assessment: Flywheel falling off
Post by: brad black on July 18, 2012, 02:13:50 AM
the bush is the wrong way around.  it goes through the bearing, through the washer and locates in the recess in the timing gear.  is the key inside the timing gear ok.
Title: Re: Damage assessment: Flywheel falling off
Post by: He Man on July 18, 2012, 07:15:04 AM
the key looks fine, theres no apparent damage on it. If i flip the bushing around then it would be in the right order? The smaller timing gear backed off the crank enough so that it wasnt engaging the larger timing gear. I just find it odd that theres nothing behind the smaller gear. it slips on bare.

(http://www.kuixihe.com/gallery3/var/resizes/Trips/Move-to-Colorado/P1020659.JPG?m=1338227450)
Title: Re: Damage assessment: Flywheel falling off
Post by: BK_856er on July 18, 2012, 01:51:42 PM
A pic of mine, fwiw.  I use a dab of grease to hold the thin washer in place against the gear and assemble carefully so it STAYS in place.

(http://i48.tinypic.com/34hdjiv.jpg)

BK
Title: Re: Damage assessment: Flywheel falling off
Post by: He Man on July 18, 2012, 01:58:10 PM
If you put the bushing in the wrong way, is there any reason why the bike wont run?  I have the larger timing gear and the one on the crank shaft lined up with the dots and the flywheel lined up with the crank shaft. but the bushing was in the wrong way and it woudlnt start. I did get a spark though, wasnt too strong though.
Title: Re: Damage assessment: Flywheel falling off
Post by: scduc on July 21, 2012, 05:04:56 PM
Doesn't that bearing work "one way only"? If I recall, and I have a spare assembly, the flywheel only locks in one direction and free-wheels in the other. So it most likely would not start as the starter would only be turning the gear and not the motor. Help me if I'm not thinking right.
Title: Re: Damage assessment: Flywheel falling off
Post by: He Man on July 21, 2012, 06:54:46 PM
thats the sprag gear youre talking about, this is just a needle bearing.