m400 - 900...here goes

[samuraibiker]

ok...i have bitten the bullet and decided to swap out the 400 engine in my 97 monster 400 for a `97 900 engine  ( 19,000 kms on the clock, gotten from a friend who swears it is is in great condition )

from what i have read, the engine should just bolt in but i was wondering about the swing arm size, any issues there?

also, my 400 is a wet clutch but the 900 is a dry one...any mods needed?

carbs...rejet possible or better to get a pair of dedicated 900s ( or even fcrs ) ?

braking...one single disc up front...sufficient?

any other advice would be very very welcome..i have swapped engines on vespas countless times but that is almost like saying ` i can bench press 200lbs ` to a powerlifter

[Slide Panda]

If you get the 900 with the clutch, then no mods at all there. Someone might have removed the clutch... but a lot of times the engines sold with the clutch

I'd guess the carb size is different to feed the more than 2x displacement.

Swingarm... I'll definitely defer to the folks with deeper knowledge. But if you retain the 160 wheel, I *think* it should be a bolt up job.

Braking - you can always stay with the one disc until after you get the 900 in. If things feel weak on the brakes with the extra mass of the 900, there's plenty of options to explore.

[samuraibiker]

hey s panda

engine does come with the clutch

wondering about the manifolds.... same size?

sticking with the standard wheels ...for now !

good idea about the brakes...i dont even feel the need to use the back brake now ( except for a quick dab in the middle of a corner when going a wee bit too fast  )

thanks for your help

mike

[Howie]

As a starter, no modifications needed for the dry clutch itself, but some work may need to be done to get the fluid line to work and you might need a different size master.  Carbs are 38s so they will work, but definitely need jetting.  Your wallet  is probably the guide between FCRs or rejetted Mikunis.  If you go the FCR route, Chris Kelly
http://www.ducatimonsterforum.org/index.php?PHPSESSID=89trjeeuv7i0pnqv3rmurp3j97;www;board=75 is your man.  Exhaust headers won't fit.  Dual disk might be a good idea since that was the OEM set up for a 900.  This will require a 16 mm. master cylinder.  You might want to get a 5.5" rear wheel so you can run a 180 tire and put a 120/70 up front.  You might run into a sprocket alignment issue, nothing we couldn't get you through.  I'm sure there are details I didn't think of.

All in all, a very doable project.

[Slide Panda]

Oh the headers? yeah you'll need those. The ones for the 900 *should* be the same diameter. But they will be notably longer.

[koko64]

You need 900 manifolds.
Plans for the motor? If so, now is the time.

Frame/motor studs are fine. Maybe stronger ones from TPO or Nichols?

[koko64]

Is the 900 engine from a Supersport or S model Monster?

[samuraibiker]

hey guys

fantastic advice..thanks

hey s panda....

new motor is a 900m ZDM904A2... got it for $200..

not planning on doing much work to the engine except for KN air filters, new pipes ,a lightened flywheel and oberon clutch and if i can afford it...fcr`s ( about $450 here used ).

very good idea about frame motor studs...am stripping the bike totally for frame repaint so perfect time

hey howie

thanks...will definitely keep my eyes on that clutch line and i was planning to repaint the standard wheels so it would be a great chance to upgrade the wheels too!

engine arrives next week..then it`s the final ride as a 400 before the madness commences!

[koko64]

Ask your buddy if the heads have W or V stamped on the heads.

[koko64]

Get some FCRs if you are leaving the motor stock.

[samuraibiker]

hey koko

engine arrived ...cant see any v or w... where should i look?

the engine only did 19,000 kms ..... dont know its history so should i get it checked out first before swapping?

deffo going to get fcrs...had one on my kawasaki klx....monster difference!

cheers

mike

[koko64]

On the side of each head on the rocker box there will be a V or W stamp. Brad from Bikeboy.org has a report on "Not all 900s being equal" which outlines the substantial differences of the hp potential of each motor.
It's worth a compression test, examining the oil and the plugs or even taking off the heads for a look. At such low kms and coming from a buddy, your odds are good.

[runeight]

Subscribed.

r8

[Speeddog]

[samuraibiker]

superb speed dog... cant get clearer than that

hey koko..have read that page ( read it before deciding to buy this particular engine ) and it doesnt say anything about v or w...but it does say  ` The best engine came in all 91 to 97 900 SS and SL bikes. These engines were also used in 900 Monster up to engine number 037727 ( late 1996 build ) and the 98/99 900 Monster Special `
the engine i just got is a 96 so fingers crossed it is one of the good ones!!!