watch this fool swap a '96 900ss engine into an '01 M750

[Real Recognize Real]

The bird chirping sounds nice

[ducatiz]

Lol He came buckets

had her running today...like, REALLY running...and....OMFG. Just an ANIMAL. Between the FCR's fukn ROARING when they gulped fuel and air...to the new engine through my RR exhaust...to the clackity clack of the open dry clutch...wow...just...wow. OMFG. wow. Then these came in the mail today to top it off. What a great.fukn.weekend this is gonna be

[brad black]

Hey Brad;

is there an advantage to using these over the blue ones?

the blue ones don't cover the main air and idle air jets, and they don't have a specific filter mounting section.

[Rudemouthsky]

the blue ones don't cover the main air and idle air jets, and they don't have a specific filter mounting section.

you don't think I'd need different jets after the pods + velocity stacks, do you? I have the 155

thanks dude

[brad black]

I don't think I've run 155 in any of the fcr fitments I've done so far.  finish it and dyno it.

[Rudemouthsky]

I don't think I've run 155 in any of the fcr fitments I've done so far.  finish it and dyno it.

Chris's settings out of the box:

Fuel screw    3/4 turn
Slow Air Screw    1-1/2 turns
Float height    9mm
Main Jet    155
Main Air Jet    200
Slow Jet    60
Needle    EMT
Needle Clip    3rd from top

[brad black]

my playing with them:

http://www.bikeboy.org/900SSwithkeihinfcr39and41mmcarbs.html

[SDRider]

Love this thread!  Keep the updates coming.   

[Rudemouthsky]

my playing with them:

http://www.bikeboy.org/900SSwithkeihinfcr39and41mmcarbs.html

I'm a little confused now. Read your write up, and it seems that with the 41's all you changed was the slow jet. So if you never use the 155 when you fit them on your customers bikes, what do you use?

Engine is all stock, the only mods that effect fuel/air are the airbox delete /pods and the RR exhaust.

thanks again.

[Rudemouthsky]

Love this thread!  Keep the updates coming.   

Thanks man. I'm really thinking that having this documented for posterity will be helpful for lots of ppl. The baby Monsters (600/620/750) have a frustrating lack of power to lots of people.

I do wish I'd taken more pics along the way but I have a few. After this is done I'm going to go back through the posts and make edits, add notes, and Tom and I will also come up with a bullet list to add.

today I have to address the oil cooler, it's held on by zip tie. The cooler mounts are different and I'm hoping I can swap the 750 mount with no problem.

it's been said that this swap is an afternoons worth of work, but I call BS on that. There are just too many unexpected variables and you need to take your time. Maybe if you've done the swap several times before you could roll through it in a day but even then I doubt it.

[brad black]

I'm a little confused now. Read your write up, and it seems that with the 41's all you changed was the slow jet. So if you never use the 155 when you fit them on your customers bikes, what do you use?

Engine is all stock, the only mods that effect fuel/air are the airbox delete /pods and the RR exhaust.

thanks again.

sorry, thought i'd used some different mains.

[Rudemouthsky]

sorry, thought i'd used some different mains.

so...sorry if I seem obtuse, but just to confirm; 155 is the main jet you stuck with? looks like you did dyno the 41's with a 152 main, then settled on the 155 as delivered but with a 52 pilot? I can't tell if you have seperate dyno chart of 155 vs 152 on that page. Or if changing the pilot had any benefit other than curing the rich idle.

looks like I'll be fine just leaving them alone, including the slow jet. It gets really cold here.

edit: now I see where you experimented with the different main jets but I can't quite tell how or why you settled on the 155. *shrug*...doesn't matter.

edit #2: looks like there's very little difference between no snorkels and open airbox...also did you use velocity stacks?

thanks and sorry about all the pestering.

[brad black]

yes, 155 mains.  I possibly would have gone a bit richer, but the 41 tend to have a fairly rounded air/fuel ratio curve that you have to compromise on.

I found the std 60 pilot jets to be so rich that the bikes would run badly at low speed.

on a bike jetted to work with no airbox lid fitting a lid without snorkles makes very little difference ime.  a std carb bike with std jetting will run without snorkles, but not without lid.

[MotoPsycho]

Not to thread jack, but say a guy has a 750 with the intention of getting a 900 motor to do the exact same swap. Would it make sense to get 41's and re-jet instead of 39's and it not be enough?

[Rudemouthsky]

Not to thread jack, but say a guy has a 750 with the intention of getting a 900 motor to do the exact same swap. Would it make sense to get 41's and re-jet instead of 39's and it not be enough?

I actually called Chris Kelly with the exact same question 2 years ago, told him that I had future plans to do this swap. He was so adamant about 39 for 750 and 41-900 that he practically refused to sell them to me. (which I thought was awesome of him). From what I've researched since then, starting with 39's and rejetting them for your 900 is the best way to go if anything. There are some that still insist the 900 gets along with the 39 even more so than the 41. And Brad will correct me if I'm wrong but from reading his write ups, he seems to feel the difference between the 2 for the 900 is *somewhat* negligible, with the 41's having a slight edge. Almost everyone whose opinion I covet seems to agree that the 41's will "overwhelm" the 750.

So...my Monster M750 now has an M900 rear wheel and a Supersport 900 engine...what should I call it since it's not an M750 anymore? Super Monster? Monster SS? hrrrm