Hi there,
Riding a 906 for a couple of weeks now and I do have a (minor?) problem with it.
When riding under the 2500 rmp and when I want to accelerate the engine holds in and starts to backfire a little bit. When opening throttle very, very slowly, there's no problem.
It's also a bit non responsive on the throttle after closing it and opening again at higher speeds.
When opening more than 1/2 there's now problem at all. Goes like a lunatic!
Does it sounds familiar to someone? Is it the Weber or should I search somewhere in the electrics?
Best,
Menno
Nervous Engine below 2500 rmp
- persempre907
- paso grand pooh-bah
- Posts: 3312
- Joined: Tue Dec 06, 2005 12:00 am
- model: 907 I.E.
- year: 1992
- Location: Roma, Italia
Re: Nervous Engine below 2500 rmp
Welcome Menno,
I'd say that less than 2500 rpm are very low for a carbed V twin, so that you can't pretend a smooth acceleration.
On my 906 (less on the 907), the bike used to jerk along.
No matter, it's really hard the tuning of the Weber...
Ciao
I'd say that less than 2500 rpm are very low for a carbed V twin, so that you can't pretend a smooth acceleration.
On my 906 (less on the 907), the bike used to jerk along.
No matter, it's really hard the tuning of the Weber...
Ciao
Francesco
Ducati 907IE 1992 Rosso
Ducati 907IE 1993 Nero
Moto Guzzi Galletto 1960 Sabbia
BMW R Nine t 2019
Ducati 907IE 1992 Rosso
Ducati 907IE 1993 Nero
Moto Guzzi Galletto 1960 Sabbia
BMW R Nine t 2019
- jcslocum
- paso grand pooh-bah
- Posts: 1714
- Joined: Mon Jul 19, 2004 12:00 am
- model: 750 Paso
- year: 1988
- Location: Eastern Shore, MD
- Contact:
Re: Nervous Engine below 2500 rmp
Menno,
Sounds like the carberettor needs to be tuned and the throttles balanced. Riding the engine at this low RPM will also make the engine very "jerky" and it will shake a lot. Keep the revs above 3500 RPM all the time and it will be smoother.
Sounds like the carberettor needs to be tuned and the throttles balanced. Riding the engine at this low RPM will also make the engine very "jerky" and it will shake a lot. Keep the revs above 3500 RPM all the time and it will be smoother.
-
- paso grand pooh-bah
- Posts: 1878
- Joined: Wed Dec 05, 2007 12:35 am
- model: 906 Paso
- year: 1990
- Location: New Zealand
Re: Nervous Engine below 2500 rmp
I agree with the above comments in that they are a bit poxy at low ish revs , but if you are into "fiddling" I would check the fuel flow from tank to carb ( as a matter of course ) but mostly I'd be interested to confirm that both accelerator pump nozzles are discharging. remove air box , look down throttle bores and open throttle and you should see two squirts of fuel ( one per venturi ). you dont say how old the spark plugs are , or how long since the valves were "done "
Ps the accelerator pump test should be done with the motor NOT running. Ha ha ha I just had this mental image of some guy with an eyeball hovering over each venturi ( there about the right distance apart ) tweakin the throttle coz if it decides to spit back , which it will probably do without the air box assy............. the injury ( whilst hysterically funny to any bystanders ), would not be nice , and it is difficult to explain to everyone where all your face hair went
Good luck
Ps the accelerator pump test should be done with the motor NOT running. Ha ha ha I just had this mental image of some guy with an eyeball hovering over each venturi ( there about the right distance apart ) tweakin the throttle coz if it decides to spit back , which it will probably do without the air box assy............. the injury ( whilst hysterically funny to any bystanders ), would not be nice , and it is difficult to explain to everyone where all your face hair went
Good luck
I wish I was young again............Id be heaps smarter than last time
- ducapaso
- paso grand pooh-bah
- Posts: 1097
- Joined: Sun Aug 01, 2004 12:00 am
- model: 750 Paso
- year: 1988
- Location: siena, italy
- Contact:
Re: Nervous Engine below 2500 rmp
Have a look to my suggestions for carb tuning in the 750 F.A.Q. post
have a nice ride, Nicola
Black "DUKE" 751582
ex...Red "smooth" 753349
Black "DUKE" 751582
ex...Red "smooth" 753349
- JWilliam
- Posts: 331
- Joined: Wed Oct 06, 2004 12:00 am
- model: 906 Paso
- year: 1989
- Location: Nottingham, UK
Re: Nervous Engine below 2500 rmp
These Ducati twins don't feel great below 2500 rpm at the best of times. When you mention the throttle lag at high rpm, I get that too, don't know why - its the sort of throttle response I would expect from a 2 stroke. The Weber can be tweaked somewhat, the other things to check are the standard ignition coils. If they have too low an impedance on the primary coil they will overload the ignition unit causing backfires and poor timing throughout the rev range.Menno wrote:Hi there,
Riding a 906 for a couple of weeks now and I do have a (minor?) problem with it.
When riding under the 2500 rmp and when I want to accelerate the engine holds in and starts to backfire a little bit. When opening throttle very, very slowly, there's no problem.
It's also a bit non responsive on the throttle after closing it and opening again at higher speeds.
Re: Nervous Engine below 2500 rmp
Hi Guys,
Thanks for the comments so far. Think I will start with the Weber. Allthought it might take a little while because last weekend the cluch broke down. The pressure cilinder (slave) has found a way right through the pressure plate! Completely worn. Ordered some parts; new cilinder and a used pressure plate. Have to fix that first. We have to keep on riding of course.. Keep you posted.
Menno
Thanks for the comments so far. Think I will start with the Weber. Allthought it might take a little while because last weekend the cluch broke down. The pressure cilinder (slave) has found a way right through the pressure plate! Completely worn. Ordered some parts; new cilinder and a used pressure plate. Have to fix that first. We have to keep on riding of course.. Keep you posted.
Menno
- ducbertus
- paso grand pooh-bah
- Posts: 531
- Joined: Sun Jan 07, 2007 12:00 am
- model: 907 I.E.
- year: 1991
- Location: holland
Re: Nervous Engine below 2500 rmp
Hi Menno,
Maybe you check your fuelpressure too.
I had a 900SS with weber. No fun.
it profed difficult to the card.
later I read somewhere that Ducati had "forgotten" to build in a fuel pressure regulator, which probably could have cured my problems at that time.
good luck
Ducbertus
Maybe you check your fuelpressure too.
I had a 900SS with weber. No fun.
it profed difficult to the card.
later I read somewhere that Ducati had "forgotten" to build in a fuel pressure regulator, which probably could have cured my problems at that time.
good luck
Ducbertus
Re: Nervous Engine below 2500 rmp
Start with new spark plugs and work from there. Cheap things first!
Brake late & brake hard,
jomo
Paso 906 Blue
Paso 906 Silver
Bultaco Metralla GT370 Custom
Bultaco Metralla GT250
Bultaco Frontera 250 Mk.9
Suzuki RMX250
jomo
Paso 906 Blue
Paso 906 Silver
Bultaco Metralla GT370 Custom
Bultaco Metralla GT250
Bultaco Frontera 250 Mk.9
Suzuki RMX250