Ducati Monster Forum

Moto Board => Tech => Topic started by: mxgrant185 on January 29, 2013, 08:10:55 AM

Title: Carbed 900 won't get above 60?
Post by: mxgrant185 on January 29, 2013, 08:10:55 AM
Here recently my m900 started to backfire if I got on it in first or second. After talking to several mechanics and calling the ducati dealership in Osage beach Missouri I came to the conclusion one of my jets were most likely clogged. I pulled my carbs ( which was way more difficult to do than my rmz-250) flushed out the jets with carb cleaner and reassembled everything. When I fired it up to make sure all was well, it was running like I had takin the air box off and it was getting WAY TO MUCH air to the point ofbogging itself down. But idles fine? Anyone know what's going on?
Title: Re: Carbed 900 won't get above 60?
Post by: ducpainter on January 29, 2013, 09:36:04 AM
Check your plugs.

I'm thinking either the vent tubes for the carb diaphragms is blocked/kinked, or you have a torn diaphragm and the slides aren't lifting.

It actually is running very rich, I'll bet.
Title: Re: Carbed 900 won't get above 60?
Post by: memper on January 29, 2013, 01:33:43 PM
Its broken. You should just give it to me.
Title: Re: Carbed 900 won't get above 60?
Post by: mxgrant185 on January 29, 2013, 04:58:25 PM
Quote from: memper on January 29, 2013, 01:33:43 PM
Its broken. You should just give it to me.

I'd rather get rid of my fiancé than get rid of my duke. I did notice the diagram did seem a little rough when I opened the sleeve of the carbs up and my float return springs were a little weak. But would that cause it to bog down that much? I can hear my intake sucking in air while ridding
Title: Re: Carbed 900 won't get above 60?
Post by: brad black on January 29, 2013, 05:16:25 PM
Quote from: mxgrant185 on January 29, 2013, 04:58:25 PM
I'd rather get rid of my fiancé

pics?

[laugh] [laugh] [laugh] [laugh]

come on, you know you were thinking it too.
Title: Re: Carbed 900 won't get above 60?
Post by: brad black on January 29, 2013, 05:18:54 PM
bot

i'd assume you did something wrong.  helpful today aren't i?

how far down did you pull the carbs?
Title: Re: Carbed 900 won't get above 60?
Post by: mxgrant185 on January 29, 2013, 09:40:33 PM
Haha five ten, blonde hair blue eyes, you got any spare parts layin around you would like to trade for? Lol jk jk jk I pulled the carbs completely off, took the bowls off, pulled the jets, took the top off and sprayed down the spring and needle then reassembled and put back together. She starts and idles fine, it's just when I actually start moving that it acts up.
Title: Re: Carbed 900 won't get above 60?
Post by: ducpainter on January 30, 2013, 02:47:32 AM
Quote from: mxgrant185 on January 29, 2013, 09:40:33 PM
Haha five ten, blonde hair blue eyes, you got any spare parts layin around you would like to trade for? Lol jk jk jk I pulled the carbs completely off, took the bowls off, pulled the jets, took the top off and sprayed down the spring and needle then reassembled and put back together. She starts and idles fine, it's just when I actually start moving that it acts up.
Have you checked to see if the slides are lifting when you open the throttle?

Did you make sure the little o-ring under the diaphragm cover was there and in place?
Title: Re: Carbed 900 won't get above 60?
Post by: mxgrant185 on January 30, 2013, 08:31:59 AM
Quote from: ducpainter on January 30, 2013, 02:47:32 AM
Have you checked to see if the slides are lifting when you open the throttle?

Did you make sure the little o-ring under the diaphragm cover was there and in place?

The slides were liftin but I didn't check the o ring
Title: Re: Carbed 900 won't get above 60?
Post by: mxgrant185 on March 31, 2013, 01:11:27 PM
I took everything back apart last night. One of the diaphragms had a slight tare in it. I fixed that and put everything back together. She def gets above 60mph now but is still having the back firing issue. Anyone know what could be wrong? Valves, shims, jetting, timing? I'm lost on this one.
Title: Re: Carbed 900 won't get above 60?
Post by: the_Journeyman on March 31, 2013, 02:05:08 PM
By fix, did you replace the damaged diaphragm?  How carefully did you check them?  My carbed 750 was sluggish and both diaphragms hit a lot of tiny cracks only visible when you put a light source behind them

FYI you can get Suzuki DR650 diaphragms for WAY cheaper than the Ducati part.  The only difference is you have to pop the diaphragm off (just a plastic circlip to remove) and put the Suzuki one on.  I think I spent $27 for each diaphragm when I replaced mine.

JM
Title: Re: Carbed 900 won't get above 60?
Post by: mxgrant185 on March 31, 2013, 03:07:53 PM
I fixed it with a little bit of silicon gel. The diaphragm was cracked towards the top, right where it holds the bend and then has the rim. It completely fixed the boggy feeling but still has the back fire issue
Title: Re: Carbed 900 won't get above 60?
Post by: the_Journeyman on March 31, 2013, 04:17:10 PM
I'll be surprised if that is the only cracks and the silicone gel survives all that long.

JM
Title: Re: Carbed 900 won't get above 60?
Post by: SpikeC on March 31, 2013, 05:52:56 PM
 Time for new diaphragms.
Title: Re: Carbed 900 won't get above 60?
Post by: mxgrant185 on March 31, 2013, 07:08:51 PM
I def do need new ones, it was just a quick fix. Would that cause the backfiring though?