Backfire & poor running
 

Help.

Rode to the Ally Pally show today, and my 1993 900ss (carb model obviously) was backfiring all over the place (on the over-run, and also on a neutral throttle at low revs).

I have never suffered this problem before. Also, low speed running is very rough, and she will barely tick-over at idle. Every time I stop at lights and pull the clutch in - it stalls.

Anyone got any clues please?

A mate of mine has a 900 ss and it did the same once and then nothing for ages and then it did the same again. He found the problem to be his fuel breather pipe filter was blocked. Simple but frustrating. Take it out of the line and blow through it. It should blow through free if not its blocked.
It creates a vacuum i suppose, which stops the fuel being pumpped properly!
May be the same.

Other wise can't help.:puzzled:

So, what is the show like and are Augusta there?

:puzzled:

Augusta were not there directly, but there were a few tasty MV's in the "Italian" exhibition section (but only one Duke - a fairly standard 998s)

Show was very busy - go on a weekday if you get the chance.
Dave.

I nailed it all the way down the A1(M) from Stevenage to the North Circular, at speeds well over the ton. Fuel starvation would have showed up then wouldn't it?

Thx anyway.
Cheers
Dave.

Carb Icing.

Felt like it wanted to cut out or a spark plug had gone bad? Fairly nippy out but not freezing and a bit dampish? Bike felt OK with throttle wide open?

Slkoline Pro FST or other such stuff.

Darren

thats exactly what my 600ss does in these conditions goes really well when its being throttled hard but runs poor at lower revs and back fires on the over run -sounds great--i changed to ultimate unleaded and all but alleviated the problem except in extreme cold conditions - went one stage further and added FST and problem solved!! also experienced the low tickover and stalling in really cold conditions

i take it that the bike hasnt got carb warmers?not sure what year ducati started to fit them

Carb kit became available in 1992 but was not fitted as standard until 1997.

Sadly the Mikuni Carbs are well known for icing - tank vent is still worth checking out as well.

Frank

[Edited on 31-1-2005 by Iconic944ss]

I've got carb warmers fitted to my bike but they're as much use as a chocolate teapot...

Darren

Yep - that pretty much describes it. I know I have suffered carb-icing before, but never back-fires.

What is Silkolene Pro FST :puzzled: ? An octane booster :puzzled:?

I always use super-unleaded anyway (Shell Optimax)

Thanks to all for your advice.

Cheers
Dave.

Well, if you have eliminated the breather hose (do you use a tank bag that may slide forward and bend the hose at low speeds) and the carb icing problem, I would check the carb fittings. See if they are on nice and snug, with no air leaks around the mountings. I had similar problems and tightening up the mounts cleared them up.
93 750SS

Darren - tried Silkolene Pro FST - works a treat :sing:

Thanks for the advice mate.

Cheers
Dave

Some good guys on here eh?

As an aside - I was surprised how much water was in my tank and and float bowls when last drained.

Happy riding - Frank

Frank, how did you discover this, and how did you drain it?

I know how to do this for a diesel engine (:lol:) but never imagined it to be a problem on a bike.

Cheers
Dave.

Two seperate occasions Dave....

Drained the Carbs the first winter I had the bike (there are drain screws on the float bowls and I ran hoses off them to collect the dregs).

and....last month I drained the tank to inspect for corrosion that I had seen previously.....I reckon there was about 50mls of water came out - surprised me.

Frank

Funnily enough these are the exact symptoms my 600ss was showing last week. Finally traced it to a knackered coil on the back cylinder. Pinched one off my 900 and all's well (until the 900 finds out!).

Think I'll get some FST in just in case!:)

Ali

exactly what i have a litre of at home now for just such an occasion.