Help with 2000 Monster 750

[The Stig]

Are there any Monster experts in Southern Maryland (St Mary's county)?

My 2000 Monster 750 is running rough at low rpm. It is running rich(black smoke/flame), fouling plugs, and backfiring. Runs great at high RPM's. I realize that the problem is likley worn needle jets, after reading through forums. I am just looking for a little direction on what to do exactly. I haven't messed with carbs much, and am concerned with messing something up. I have a Haynes manual, but still am lost.

To add a little more info, I was just out messing with the bike...
  It starts up and idles just fine. When I rev it, it runs rough, belches flames, and pops, then smooths out as the rpms increase. This is exactly what it did to me on cold days when starting, however, it would go away once warm.
Now it persists.

Some of the Harley guys I was talking to about my problem, asked me if I had tried the sparay carborator cleaner? Do any of you have experience with using it?

Rob

[zooom]

have you had the bike long?...where did the bike come from?....maybe it started out jetted wrong and just increasingly got worse...

the carbs are pretty basic...actually if you got to ducati.com , I think they still have a parts catalog available for your bike online and you can see the breakdown of the carbs to see how simple they are and see about taking them apart and while you are at it, might as well just over all freshen them up....some of your problem though, could be the valve train out of spec...not sure if you have had it checked recently or not...

[The Stig]

I have had the bike for a year. It has run rough in the past, but only when cold. I have had to replace plugs a couple times, so I imagine the problem has been there, just that now the new spark plugs don't help.
Are you saying that a valve adjustment might be in line?

[zooom]

Are you saying that a valve adjustment might be in line?

yep...how many miles on it?...both now and when you got it?...and I am guessing by your response, you have never had it done or done it yourself...

[The Stig]

About 9500 miles when I bought it. 11500 on it now.
No, I hae not performed any real maintenance on the bike, nor do I really know exactly how.
I have rebuilt a carb for a Yamaha 100cc single cylinder kart engine. I also perform a lot of the maintenance on my cars, but have really never messed with valve adjustment, or carbs.

[zooom]

sounds to me like that should be your 1st order of business then...do the valve adjustment and a new set of belts....if you have the inclination to do it yourself and have the feeler guages and whatnot...look into the desmo times 2 valve DIY guide by LT Snyder  (see desmotimes.com )as it will be an invaluable tool...if you don't have the inclination to do it yourself...you might want to just take it to a dealer to do then...

[MongoReturns]

I certainly wouldn't call myself an expert on anything but.... 7 years and 17,000 miles on my M750.

You should do the things Zoom recommends, however first thing I'd do is monkey with the mix screws - they're a PIA to get to, on the front of the carbs.  Screw them all the way in (remember how many turns in to lightly seat, to reverse if need be) then back them both out, maybe two full turns at first.  Or you could try no turns (would give the richest idle-low rpm mix I think).

I think mine are set at 3.5 turns, maybe 4.  Also, if the screw holes are covered up with a plug, you've got a stock carb.  Doubtful, if that's your exhaust in the pic, however if you've got a free-flowing exhaust and stock carbs you'll have issues.  But I think those would be lean instead of rich issues.

[The Stig]

Thanks guys.
I will look for the carb screw this eve.
I also think the valve adjustment doesn't look to hard either.

[harold]

I've got the LT snyder book and the factory Ducati manual if you want to check out whats involved. Also carbs and parts from when I re-jetted the stock mukinis (Running flatslides now whoo hoo!)Belts are pretty straight foward to replace . If you want to work on the bike this weekend drop me a line and I'll give you directions.

just Harold

[jetpuff716]

STIG,

I live near Greenwell State Park and have a trailer with a condor bike chock mounted that you're welcome to borrow if you decide to take it somewhere to be fixed.  HINT:  Duc Pond (figure about 3 hrs to get there though)

//Tony

[The Stig]

Thanks again guys.
I updated the original post with a little more info.
Hopefully I will have this fixed with Harolds help by the weekend.

Rob

[The Stig]

My bike appears to be fixed. Harold helped me with the jets, but I actually think that I just had bad gas in the bike. I put Shell 93 octane in the Monster and also put in a a shot of that Lucas Octane booster. The Monster runs like a champ now. I have been through 4 tanks of gas without a hick-up from the Duc.
Thanks for all your help guys:-)
Rob

[harold]

Rob,
Glad to hear that its running better. (I am on the road this week till saturday). 
cheers
just harold