1999 monster 750 not as snappy at my friends carbed 620. What should I do

[koko64]

For an economical solution, follow the gearing advice, fit a jet kit with K&N filter and open air box.
A more pricey solution is to buy the FCR 39 carbs as well.
Another solution if you prefer the air cooled Monsters is to sell the bike and get a 900 injected or carbed model and you might pick up a carbed 900 with FCR 41 carbs, etc.
For the extra price of the FCRs you might pick up a 900 in your part of the world.

[drewbabich]

Cool.  I have a drz400sm with the airbox side cut open and jetted.  Do you just cut open a hole on the top of the aibox on this one as well?  Are their any guides online.

Yea I suppose new jet needles would be the way to go since the stock ones have 8000 miles on them and are 12 years old. 

Yes the air box is stock, has a paper filter and does have two snorkles coming out of it. 

I'll try and get a picture of the bike posted up here.  I like the look of the two into one exhaust but it'd be cooler if it was a high mount.  It also does not sound nearly as sweet as the remus on the 620. 

Also, is the remus stock on my friends 620.  It says remus on the back of the pipes and ducati performance on the sides of the pipes. 

[drewbabich]

Another question.  When i did have the airbox open and was spraying seafoam into the carb I noticed the left carb slide door opened a tiny bit when I'd rev it up, but the right one never moved. 

Is that normal?  Does that mean my carbs are out of sync.

What controlls how those slides open.  I guess on idle in the driveway they don't open much, but riding down the road they open quite a bit?

[Howie]

For an economical solution, follow the gearing advice, fit a jet kit with K&N filter and open air box.
A more pricey solution is to buy the FCR 39 carbs as well.
Another solution if you prefer the air cooled Monsters is to sell the bike and get a 900 injected or carbed model and you might pick up a carbed 900 with FCR 41 carbs, etc.
For the extra price of the FCRs you might pick up a 900 in your part of the world.

Actually, US carbed Monsters came out of the factory leaner than what most of the rest of the world got.  There was (is) a stage 1 Dynojet kit designed for a closed air box and stock exhaust or slip ons.  As I remember, different main, needle and spring.  This would relieve the cold blooded running and low speed throttle issues.  

[Howie]

Another question.  When i did have the airbox open and was spraying seafoam into the carb I noticed the left carb slide door opened a tiny bit when I'd rev it up, but the right one never moved.  

Is that normal?  Does that mean my carbs are out of sync.

What controlls how those slides open.  I guess on idle in the driveway they don't open much, but riding down the road they open quite a bit?

Not normal.  The slides are open by vacuum.  They will open more (assuming they are working) under load.  This could be a synch issue or a bad diaphragm. Check synch first.  The diaphragms are expensive.

[drewbabich]

Did you check your sync via the vacuum gauge method that chris talks about on his website:
http://www.ducatisuite.com/carbsynch.html

I looked for the brass nipples on the pipe between the carbs and the engine.  My fitting is silver metal not brass and it looks like a allen head fits in it. 

Do I just thread this out to check the vacuum?

[koko64]

The air box lid is cut open leaving a square frame that clips down. Don't do this until you have the appropriate jet kit from Factory Pro or Dynojet, or the bike will run like crap. Their websites will reference the kits for your model and mods.


You need a K&N filter too. Paper one doesnt like wet conditions.

Carbs should open the same for the reasons mentioned. I would also change the needle jets with Factory Pro ones. The stockers wear out quickly. All this stuff is available from Cal Cycleworks.

The manometer will sort the synch. You done it before?

[Slide Panda]

You need a K&N filter too. Paper one doesnt like wet conditions.

FWIW you don't need a K&N branded one - you just need something that isn't paper media if you open that box top. K&N and BCM are oiled (important to oil them!) cotton supported by wire mesh. There's also foam filters from Piper Cross
http://www.pipercross.net/motorcycle/applications.asp?m1=6&m2=119

[MongoReturns]

I got a fancy aluminum "rig" with my k&n, that uses the stock clips and looks like it won't stay on, but it always has.  In retrospect I should've dremmeled the stock lid, it just sits around.  I can't bear to throw away Ducati parts.

[Howie]

Did you check your sync via the vacuum gauge method that chris talks about on his website:
http://www.ducatisuite.com/carbsynch.html

That will work, I prefer something like carb sticks (mercury manometers), Twin Max (what I use) or you can build these 
http://www.powerchutes.com/manometer.asp

I looked for the brass nipples on the pipe between the carbs and the engine.  My fitting is silver metal not brass and it looks like a allen head fits in it. 
do I just thread this out to check the vacuum?

The nipples have been replaced with those screws.  If you stop by a dealer they probably have a bunch they took off other bikes.  They might throw you a couple.  If not, whatever tool you buy should come with adapters.

[The Mad King Pepe']

FCRs make a huge improvement in throttle response, but are $$$ - might make more sense to sell and get a DS1000-powered monster or even a 4-valver if you are after power/$$ in a monster.

+1 on that. I have a 2001 M750 and had thought about putting on FCRs, big bore kit, M800 heads, 6-speed tranny, etc, etc. In the end I just got a Factory Pro jet kit from ca-cycleworks.com and enjoy the bike for what it is: a simple bike you can have loads of fun with.

[turbodude]

See above post.  I would spend the $100 on the factory pro kit and cut the stock airbox.  Maybe change the front sprocket.  The jet kit and open air box will make the throttle response much better and it's not too difficult to install.  I While I really like the FCR's, at that point ($$$) you are better off looking for a used 900 or something. 

[muskrat]

I've had both the 750 & 620.  The 620 feels and runs better IMO.  Move to a 900 and you will smile again