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

[drewbabich]

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

I'm comparing it to my girlfriends monster dark 620.  I know the 620 is supposed to be fuel injected, but this one definitely has a choke.  Did they make the 620 in 2002 in dark with carbs?  I can't find it online anywhere. 

The reason I ask i could understand a fuel injected 620 feeling more powerful then my 750, but not a carbed one.  She swears it says 620 on the tank.  I need to go home and check for sure. 

What should I do first.  This 1999 750 has 8k for miles and the valves, carbs and belts were not done at 6k. 

I wanted to check the compression but i don't have a fitting for the smaller plugs.  What compression range should I be seeing. 

[Monster750ie]

In 2002 all monsters were injected. The "choke" you refer to is an idle control to warm the bike up.

As far as the 99' feeling less snappy, clean the carbs, full tuneup, make sure belts are changed. Check ignition for good spark etc...

[Cloner]

Get a 620?   

[ducatiz]

Snappy?

I would make sure the bike is performing correctly.  When was the last service on it? 

Check out some kind of EFI tuning like a PCIII or similar and have it dynoed.

Also, the 750 can be fun but it's not a race bike.  60hp.  Shed weight, to get more out of it, but it will never be comparable to a 700cc I4

[greenmonster]

620 is snappier than a carb 750.
And different gearing, 43 rear f e.

[bikepilot]

Yep, that's how it is.  The 620 makes about the same power, but revs quicker, is more responsive due to the FI and they are typically geared lower.  FCRs and lower gearing would make your 750 very snappy. 

FWIW most FI bikes of the 90s had fast idle levers (ducati was about 5-6yrs behind in adopting FI).  A lever on the bar does not equal a choke.

[ducatiz]

Yep, that's how it is.  The 620 makes about the same power, but revs quicker, is more responsive due to the FI and they are typically geared lower.  FCRs and lower gearing would make your 750 very snappy. 

FWIW most FI bikes of the 90s had fast idle levers (ducati was about 5-6yrs behind in adopting FI).  A lever on the bar does not equal a choke.

i read that he had an efi 750... duh

[drewbabich]

We'll that clears a lot up.  Thanks guys.  I went home and checked and hers is in fact a 2002 618cc and that idle lever explains a lot.  Damn.

So even if I get all my service done and clean the carbs, does that mean the bike still is not going to feel as quick as her 620?  

That is a bummer.  

I thought the 750 was gonna be nastier.  

If I wrap the throttle and pull the bars I can get my front wheel to flutter off the ground on the 750, I can't do that on her 620.  But other then that her 620 is way more fun right now.

[ducatiz]

change the gearing, put FCRs on it. 

you will notice a difference, but it won't be a rocket.  it will beat the 620.

[zooom]

Get a 620?  

Ooooo Ooooo Ooooo...go for the Capirex and you can do 140!!!

[bikepilot]

Correct, your 750 all tuned up and running as it should probably won't be as snappy as a 620 running as it should.  Also, your wheelie technique might be off.  My wife's 620 will loft the front without much trouble  - just goes to show that wheeling isn't a good measure of performance. Gearing is cheap and can make a big difference on how snappy a bike feels.  Play around with it first and maybe it'll do all you need.  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.

Don't sweat compression, your bike isn't worn out at 8k miles.  Do keep on top of the maintenance, especially belts, if you don't want very expensive engine damage.

[MongoReturns]

Go +2 in the rear - sure you have to shift a little sooner and it'll only do 120 if dropped off a cliff, but it goes ZZZOOOMMM!!! off the line.  Assuming you've got open-ish pipes, stage 2 jets, and K&N.  If not, get that stuff too 

[drewbabich]

Thanks for the input so far guys.

I've ran it about 50 miles with seafoam in the gas, sprayed seafoam into the top of the carb with it idling and also reving while spraying.  It seems to have helped a fair amount or maybe I'm just getting used to the power delivery.  I've read about disconnecting a vacuum line on the carb and sucking seafoam directly in that way.  When I search for vacuum lines under the carb I cann't seem to find any.  Do you have to remove the air box in order to get to this?

Its also possible that since the 620 I ride has a beautiful sounding remus dual exhaust that I think I'm accelerating more then I am.  The remus exhuast sound is very progressive as in the more you rev it the more and more deep and loud it gets.  Fools you into thinking you're making a ton more power.  Kind of like driving a miata.

On the other hand my 750 with the two into one arrow exhaust is loud, but not as deep and loudness does not seem as progressive as you crank the throttle. 

Ultimately I really feel like I should take the carbs out just to blast them out with carb cleaner and an air compresser and see what the jet needle looks like.

Should my jetting be modified if I have an arrow two into one exhaust?  I don't think its a full exhaust. 

I've only ever done carbs on a snowmobile polaris 600 xc, so I think I can do these too.  It made a huge difference on the snowmobile.

I million questions I know.  Thanks for any advice. 

[Slide Panda]

Unless the intake on the 750 has been modified - freer flowing filter, open air box etc you shouldn't need a different needle/jetting. It's only when you mess with the air that you really need to mess with the fueling - just an exhaust won't (shouldn't) do it.

But you're probably due for a solid carb service at this point. I bet a new set of needles and a good cleaning will help

As all the folks have noted so far - I bet a lot of it comes down to the final drive gearing. Stock gearing for the 750 is 15/38 and stock for the 620 is 15/46
http://www.ca-cycleworks.com/shop/catalog/ducati/chain.html

- That's a good bit of difference and if the 620 is running 14/46, even more so. Even if you both had 620s and were running 15/38 on one and 15/46 on the other you'd notice the one with the bigger rear sprocket would get off a line faster.

[MongoReturns]

If you pop the tank up & see a plastic thing covering the airbox with 2 snorkles coming out of it, chances are you've got a stock filter & jets.  Taking the carbs out is the one pain I hate to do on that thing, and I've avoided it for years now since I did the jets like 5 years ago.  But it's not complicated.  And I don't think the carbs have vacuum lines - there's two air intake tubes I think on the top - they've got little permanent filters attached to them.

I'd like to see a 2-1 Arrow on this bike, haven't seen that before.