Can anyone help confirm the original carb details for a 1981 'K' model 350 Strada?
This bike came with 2 different carbs, a VHB25BS and a VHBZ25HS.
I have struggled to get it to run the way I think it should, and from reading various manuals and technical sites thought it should maybe have VHBZ25BS carbs. I now think it is possible the VHB25HS is correct (with 260D atomiser?). Can anyone confirm?
If it is the HS type, is the small diameter hose connection beside the throttle stop screw a float chamber vent and where should it be piped to?
Mine is currently fitted with a blanking plug.
I would like to start from standard before trying anything else.
Any help gratefully received.
Michael
Strada Carbs help
Michael
I have the 25 HS carbs on my '84 Kanguro 350 X1 and the 260D atomiser is correct, I am not running the standard airbox and originally had a 90 main jet which I have now increased to a 98, what main jet are you running?. The blanked off pipe you refer to is the intake vacuum connection which you use to check the carb balance and also connect a balance pipe and normally these would be connected together so you would have a one pipe going from one carb to the other. Having them blanked off should not be a problem however if the balance is not spot on or when they go slightly out of balance this balance pipe if fitted would help equalise them. Maybe you carbs are out of balance causing the running issue. Also another question for all what is the difference between the 25HS and the 25BS carbs?
Regards
Robin
I have the 25 HS carbs on my '84 Kanguro 350 X1 and the 260D atomiser is correct, I am not running the standard airbox and originally had a 90 main jet which I have now increased to a 98, what main jet are you running?. The blanked off pipe you refer to is the intake vacuum connection which you use to check the carb balance and also connect a balance pipe and normally these would be connected together so you would have a one pipe going from one carb to the other. Having them blanked off should not be a problem however if the balance is not spot on or when they go slightly out of balance this balance pipe if fitted would help equalise them. Maybe you carbs are out of balance causing the running issue. Also another question for all what is the difference between the 25HS and the 25BS carbs?
Regards
Robin
1984 Kanguro X1 home built special.
'Using yesterday's technology to create tomorrow's problem's today'
'Using yesterday's technology to create tomorrow's problem's today'
As I recall the difference between a 'BS' and an 'HS' is the presence of a vacuum takeoff port, which your description would seem to confirm. Some Morinis ran a balance pipe between the vacuum ports on the two carbs and it makes a convenient place to plumb in a set of balancing gauges.
Originaly the carbs were all designated VHB then dellorto reclassified them as VHBZ for sizes up to 26mm and VHBT from 27mm on up. There were minor detail changes on the way.
The very fact that you've got a miss-matched pair of carbs indicates perhaps an 'interesting' history for your bike.
I think I've got a spare set of matched carbs, I'll have to check.
Originaly the carbs were all designated VHB then dellorto reclassified them as VHBZ for sizes up to 26mm and VHBT from 27mm on up. There were minor detail changes on the way.
The very fact that you've got a miss-matched pair of carbs indicates perhaps an 'interesting' history for your bike.
I think I've got a spare set of matched carbs, I'll have to check.
Paul Compton
http://www.morini-mania.co.uk
http://www.youtube.com/user/EVguru
http://www.morini-mania.co.uk
http://www.youtube.com/user/EVguru
Robin/Paul,
Thanks for help so far.
The vacuum take off point on the HS carbs being used for a balance pipe makes sense and ties in with what I have read in workshop manuals for later models (K2).
I suppose I still need confirmation that the HS type carb with a balance pipe is the original spec. for my bike, although looking (squinting) at pictures of other similar bikes seems to show this to be the case.
Paul - if you do have a matched set (or even another HS type), I would be interested in them.
I have minimised the problem by careful balancing using vacuum gauges, but am still not there yet (general lack of 'oomph', flat spot around 3500-4000 rpm and a bit more vibration than the last one of these I rode)
With the mismatched set originally fitted, I couldn't get the carbs to balance on the gauges at both idle and open throttle positions (could get either but not both). Replacing the elderly VHB25BS with a secondhand VHBZ25BS has helped.
This is my wife's bike and we are going on a trip to the south of France in a couple of weeks (with me on my Corsaro 1200) so this is why I need to get it sorted soon.
Regards,
Michael
Thanks for help so far.
The vacuum take off point on the HS carbs being used for a balance pipe makes sense and ties in with what I have read in workshop manuals for later models (K2).
I suppose I still need confirmation that the HS type carb with a balance pipe is the original spec. for my bike, although looking (squinting) at pictures of other similar bikes seems to show this to be the case.
Paul - if you do have a matched set (or even another HS type), I would be interested in them.
I have minimised the problem by careful balancing using vacuum gauges, but am still not there yet (general lack of 'oomph', flat spot around 3500-4000 rpm and a bit more vibration than the last one of these I rode)
With the mismatched set originally fitted, I couldn't get the carbs to balance on the gauges at both idle and open throttle positions (could get either but not both). Replacing the elderly VHB25BS with a secondhand VHBZ25BS has helped.
This is my wife's bike and we are going on a trip to the south of France in a couple of weeks (with me on my Corsaro 1200) so this is why I need to get it sorted soon.
Regards,
Michael
Hi,
Have you checked all the jets are the same in each carb and the needle?, regarding the flat spot I get one around the 5,000rpm mark but it clears and then pulls better through 6,000-7,500rpm mark. Is you air filter in good condition, also check the rubber carb connections and air filter connections for air leaks. Also check the advance is working correctly on each transducer as it could be an ignition related lack of oomph.
Regards
Robin
Have you checked all the jets are the same in each carb and the needle?, regarding the flat spot I get one around the 5,000rpm mark but it clears and then pulls better through 6,000-7,500rpm mark. Is you air filter in good condition, also check the rubber carb connections and air filter connections for air leaks. Also check the advance is working correctly on each transducer as it could be an ignition related lack of oomph.
Regards
Robin
1984 Kanguro X1 home built special.
'Using yesterday's technology to create tomorrow's problem's today'
'Using yesterday's technology to create tomorrow's problem's today'
Robin,
Jets are same in both carbs with the exception of the atomiser which is a 260K in the BS type carb and a 260D in the HS type. Other jets are 50 pilot (tried 43 but changed back due to poor starting), 112 main and new E17-2a needles in the middle groove.
Air filters are clean, carb to filter rubbers replaced and carb to head rubbers seem ok.
The theory of using 2 x VBZ25HS carbs with a balance pipe between still seems good.
Can anyone confirm if this is standard?
Michael
Jets are same in both carbs with the exception of the atomiser which is a 260K in the BS type carb and a 260D in the HS type. Other jets are 50 pilot (tried 43 but changed back due to poor starting), 112 main and new E17-2a needles in the middle groove.
Air filters are clean, carb to filter rubbers replaced and carb to head rubbers seem ok.
The theory of using 2 x VBZ25HS carbs with a balance pipe between still seems good.
Can anyone confirm if this is standard?
Michael