Fitting lightened flywheels, M900.

Zimbo · 08-01-2006, 08:05 PM

I appear to have made a rash purchase from Kaemna in Germany, and hopefully will soon be the proud owner of a light alloy flywheel.
I intend to fit it myself if possible, but would appreciate any guidance from those who know about such things.
The bike is a 1995 900 monster.
I know I need to get the alternator side engine cover off, once that's done will the flywheel fit over the alternator, or do I need to remove the alternator first? If so, any tips on getting the nut undone, and on getting it done up again afterwards in such a way that it doesn't come undone again?
Anything else to watch out for?

Once done I'll post a review of the flywheel and whether the bike feels different etc. For those interested, the flywheel costs 98 euros plus postage, and weighs 587 grammes - that's 1250 grammes lighter than the standard one.

08-01-2006, 08:19 PM

I had a light flywheel on my S4 from the same company, my advice regard the flywheel nut is to use an air impact gun, likewise for tightening + high strength loctite.

If you don't have a compressor I believe you can hire electric versions of an impact gun.

Shaun

Pedro · 08-01-2006, 09:34 PM

Zim

the altenator wil have to come off and it's a tart to shift. I tried an impact air gun (running 20% over max air pressure) and the nut didn't move. I ended up borrowing the pukka ducati tool and using a breaker bar with a 4 foot tube over it, and bent the breaker bar.....

And don't do what I did and get the flywheel one tooth out on it's splines... it'll back fire nicely but won't run if you do.

Also, use Loctite on the nut and get it torqued up accuratly.

Ped

Zimbo · 08-01-2006, 09:54 PM

Cheers Pedro, might be worth paying someone to fit it then, I'll try and track Alan Shirly down, i hear he's still around!

gary tompkins · 08-01-2006, 11:26 PM

Quote:

Originally Posted by Zimbo

... the flywheel costs 98 euros plus postage, and weighs 587 grammes - that's 1250 grammes lighter than the standard one.

I don't know about rash purchase - that sounds like a bit of a bargain! Be interested to hear what the verdict is after fitting?

NattyBoy · 08-01-2006, 11:37 PM

Or do what im going to on the 748 and take the thing off altogether...

Sould spin up like a goodun then...!!

09-01-2006, 02:29 PM

think i read somewhere your better milling the original one down rather than getting an aluminum one ?

09-01-2006, 06:40 PM

aluminium's better if the nut comes loose, doesn't knacker the crankshaft spline up!

Zimbo · 14-01-2006, 09:25 PM

Right, update.

Light flywheel arrived, total cost delivered was Â£86 inc VAT, looks exactly like the picture I posted earlier. I bought it from here:
http://www.ducati-kaemna.de/.
It was delivered UPS and I had to pay cash on delivery. Well packaged and came with good instructions in english.

Decided after researching on the web to fit it myself.
A useful resource was an american personal site, chap took pics as he did the job.
http://www.fokust.com/gallery/album178?page=1

Made up a puller from a bit of steel plate i had lying around, drilled three holes to match the cover bolts on the outsides, and a threaded 8mm one with 8mm bolt for the centre. Worked a treat, as i tightened the bolt the entire cover came away easily. This cover breaks easily apparently, so if anybody else tries it, be carefull!
Then getting the alternator nut undone. I tried various techniques that have worked for me in the past with front sprocket nuts, including first gear and a big lump of metal through the back wheel resting on the swinging arm, nothing worked. I eventually wheeled it down the road to the local garage and borrowed his impact gun, which got the nut off in seconds!
All went pretty straightforward after that, stopped when it got dark, just need to loctite and torque the nut up tomorrow, reassemble, and test!
More to follow . . .

Out of interest Ped, was it a lightened flywheel you fitted, and if so how light was it, and did it make a noticable difference?

14-01-2006, 11:36 PM

dunno about monsters, but i fitted a lightened flywheel to my mini and it made a hell of a difference in the acceleration.

14-01-2006, 11:54 PM

handy fcr pics on fokust...so thats how the cables run. good thing I saw that.

15-01-2006, 04:35 PM

as the man says

Install shim, sleeve and bearing onto the crankshaft. Make sure the shim is centered in the bearing sleeve. .. and the shim is over the needle roller sleeve and not trapped by it.

Shaun

Zimbo · 15-01-2006, 06:14 PM

Well, all done. As it happens the shim and bearing sleeve had stayed on the crankshaft, so I didn't disturb them, just slid the new flywheel / starter gear assembly back onto the crankshaft. Cleaned the threads and nut with solvent, applied plenty of locktite, and torqued the nut up to 200 Nm. Put everything back together and it was time to see if it had worked.
First though I had to get the thing started. One downside of the Kehins is that there is no choke, so I opened the idle screw to maximum and turned her over. Nothing - not firing. Check spark - both plugs sparking.
The second downside of the kehins is that it takes a while to pump petrol through if it hasn't been used for a while, and I haven't started it for about 6 weeks, so I charged the battery up again, squirted easystart into the air filter, and tried again. Fired on the easystart but died immediately, so I repeated the process untill finally fresh fuel reached the carbs and it started and ran. Once running it was fine.
Out on the road and took it for a run. So , was it very different?
Well, yes, it was noticable! The engine spins up a lot more quickly now when blipping the throttle, easier to stall too when setting off (but then I'm used to the effortless torque and don't give it much throttle to get going if not in a hurry). I didn't actually stall, but it did cough and hesitate for a moment on a slow, low rpm start away from some lights.
When slowing down, there is a LOT less engine braking, this is the most noticable thing I found on normal riding. Presumeably it'll be less inclined to skate the back end on hard braking into hairpins then!
Last test - does it accelerate harder? Again, yes, but it's not immediately noticable really. However, the bike will now lift the front wheel off the throttle in second gear, which it never would before (that's change into second, low rpm on a neutral throttle, open throttle hard with no other inputs, front wheel lifts a foot or so as it accelerates) so it does indeed improve things. It will be more noticable in the lower gears though, I doubt you'll feel any difference in top gear.
Next step, when funds allow - high compression pistons.

15-01-2006, 06:51 PM

yes mine are spluttering, but they were bone dry and have been on a boat for two months...increasing the idle is clock wise yes? I have no rev on mine approx how many counter clock from fully in are you?

thanks.
Alex.

Zimbo · 15-01-2006, 06:58 PM

Increasing the idle speed is indeed clockwise. You'll probably find you need to increase the idle speed when starting from cold, and decrease it again when warm. It's easy, as long as you site the adjustment knob where you can reach it when sat on the bike at traffic lights etc!
When warm, mine is probably idling with the knob turned down about two to three full turns from maximum.

08-01-2006, 08:05 PM	#1
Zimbo Too much time on my hands member Join Date: Apr 2003 Location: Stonehouse, Glos Bike: Multiple Monsters Posts: 2,080	Fitting lightened flywheels, M900. I appear to have made a rash purchase from Kaemna in Germany, and hopefully will soon be the proud owner of a light alloy flywheel. I intend to fit it myself if possible, but would appreciate any guidance from those who know about such things. The bike is a 1995 900 monster. I know I need to get the alternator side engine cover off, once that's done will the flywheel fit over the alternator, or do I need to remove the alternator first? If so, any tips on getting the nut undone, and on getting it done up again afterwards in such a way that it doesn't come undone again? Anything else to watch out for? Once done I'll post a review of the flywheel and whether the bike feels different etc. For those interested, the flywheel costs 98 euros plus postage, and weighs 587 grammes - that's 1250 grammes lighter than the standard one.

08-01-2006, 09:34 PM	#3
Pedro Ciao, come stai? Join Date: Apr 2003 Location: Somewhere Bike: Multiple Monsters Posts: 4,157	Zim the altenator wil have to come off and it's a tart to shift. I tried an impact air gun (running 20% over max air pressure) and the nut didn't move. I ended up borrowing the pukka ducati tool and using a breaker bar with a 4 foot tube over it, and bent the breaker bar..... And don't do what I did and get the flywheel one tooth out on it's splines... it'll back fire nicely but won't run if you do. Also, use Loctite on the nut and get it torqued up accuratly. Ped __________________ Monster 1200R! KTM 990 SuperDuke

08-01-2006, 08:19 PM	#2
Shauns4 Guest Posts: n/a	I had a light flywheel on my S4 from the same company, my advice regard the flywheel nut is to use an air impact gun, likewise for tightening + high strength loctite. If you don't have a compressor I believe you can hire electric versions of an impact gun. Shaun

08-01-2006, 09:54 PM	#4
Zimbo Too much time on my hands member Join Date: Apr 2003 Location: Stonehouse, Glos Bike: Multiple Monsters Posts: 2,080	Cheers Pedro, might be worth paying someone to fit it then, I'll try and track Alan Shirly down, i hear he's still around!

08-01-2006, 11:37 PM	#6
NattyBoy Monsterless again for now Join Date: Sep 2002 Location: Wiltshire Bike: M900 Posts: 3,189	Or do what im going to on the 748 and take the thing off altogether... Sould spin up like a goodun then...!!

09-01-2006, 02:29 PM	#7
Scotty Guest Posts: n/a	think i read somewhere your better milling the original one down rather than getting an aluminum one ?

09-01-2006, 06:40 PM	#8
Shauns4 Guest Posts: n/a	aluminium's better if the nut comes loose, doesn't knacker the crankshaft spline up!

14-01-2006, 09:25 PM	#9
Zimbo Too much time on my hands member Join Date: Apr 2003 Location: Stonehouse, Glos Bike: Multiple Monsters Posts: 2,080	Right, update. Light flywheel arrived, total cost delivered was Â£86 inc VAT, looks exactly like the picture I posted earlier. I bought it from here: http://www.ducati-kaemna.de/. It was delivered UPS and I had to pay cash on delivery. Well packaged and came with good instructions in english. Decided after researching on the web to fit it myself. A useful resource was an american personal site, chap took pics as he did the job. http://www.fokust.com/gallery/album178?page=1 Made up a puller from a bit of steel plate i had lying around, drilled three holes to match the cover bolts on the outsides, and a threaded 8mm one with 8mm bolt for the centre. Worked a treat, as i tightened the bolt the entire cover came away easily. This cover breaks easily apparently, so if anybody else tries it, be carefull! Then getting the alternator nut undone. I tried various techniques that have worked for me in the past with front sprocket nuts, including first gear and a big lump of metal through the back wheel resting on the swinging arm, nothing worked. I eventually wheeled it down the road to the local garage and borrowed his impact gun, which got the nut off in seconds! All went pretty straightforward after that, stopped when it got dark, just need to loctite and torque the nut up tomorrow, reassemble, and test! More to follow . . . Out of interest Ped, was it a lightened flywheel you fitted, and if so how light was it, and did it make a noticable difference?

14-01-2006, 11:36 PM	#10
manc skank Guest Posts: n/a	dunno about monsters, but i fitted a lightened flywheel to my mini and it made a hell of a difference in the acceleration.

14-01-2006, 11:54 PM	#11
A Yerbury Guest Posts: n/a	handy fcr pics on fokust...so thats how the cables run. good thing I saw that.

15-01-2006, 04:35 PM	#12
Shauns4 Guest Posts: n/a	as the man says Install shim, sleeve and bearing onto the crankshaft. Make sure the shim is centered in the bearing sleeve. .. and the shim is over the needle roller sleeve and not trapped by it. Shaun

15-01-2006, 06:14 PM	#13
Zimbo Too much time on my hands member Join Date: Apr 2003 Location: Stonehouse, Glos Bike: Multiple Monsters Posts: 2,080	Well, all done. As it happens the shim and bearing sleeve had stayed on the crankshaft, so I didn't disturb them, just slid the new flywheel / starter gear assembly back onto the crankshaft. Cleaned the threads and nut with solvent, applied plenty of locktite, and torqued the nut up to 200 Nm. Put everything back together and it was time to see if it had worked. First though I had to get the thing started. One downside of the Kehins is that there is no choke, so I opened the idle screw to maximum and turned her over. Nothing - not firing. Check spark - both plugs sparking. The second downside of the kehins is that it takes a while to pump petrol through if it hasn't been used for a while, and I haven't started it for about 6 weeks, so I charged the battery up again, squirted easystart into the air filter, and tried again. Fired on the easystart but died immediately, so I repeated the process untill finally fresh fuel reached the carbs and it started and ran. Once running it was fine. Out on the road and took it for a run. So , was it very different? Well, yes, it was noticable! The engine spins up a lot more quickly now when blipping the throttle, easier to stall too when setting off (but then I'm used to the effortless torque and don't give it much throttle to get going if not in a hurry). I didn't actually stall, but it did cough and hesitate for a moment on a slow, low rpm start away from some lights. When slowing down, there is a LOT less engine braking, this is the most noticable thing I found on normal riding. Presumeably it'll be less inclined to skate the back end on hard braking into hairpins then! Last test - does it accelerate harder? Again, yes, but it's not immediately noticable really. However, the bike will now lift the front wheel off the throttle in second gear, which it never would before (that's change into second, low rpm on a neutral throttle, open throttle hard with no other inputs, front wheel lifts a foot or so as it accelerates) so it does indeed improve things. It will be more noticable in the lower gears though, I doubt you'll feel any difference in top gear. Next step, when funds allow - high compression pistons.

15-01-2006, 06:51 PM	#14
A Yerbury Guest Posts: n/a	yes mine are spluttering, but they were bone dry and have been on a boat for two months...increasing the idle is clock wise yes? I have no rev on mine approx how many counter clock from fully in are you? thanks. Alex.

15-01-2006, 06:58 PM	#15
Zimbo Too much time on my hands member Join Date: Apr 2003 Location: Stonehouse, Glos Bike: Multiple Monsters Posts: 2,080	Increasing the idle speed is indeed clockwise. You'll probably find you need to increase the idle speed when starting from cold, and decrease it again when warm. It's easy, as long as you site the adjustment knob where you can reach it when sat on the bike at traffic lights etc! When warm, mine is probably idling with the knob turned down about two to three full turns from maximum.