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Just wondering where the Morgan Carbtune II connects to the Carbs? The holes left by the metal plugs on the intake rubber appear too small for the connectors on the end of the Carbtune tubes.

Thanks,

Mike

Ideally you need a connector the same shape as the blanking plugs but with a hole through them. I seem to recall the Morgan kits came with a set of small threaded adaptors that would fit in the rubbers holes? Check the inlet tract side of your carbs for a balance pipe between the two carbs, if you have those they are ideal points to connect to. Normally only on later bikes but you never know what's been swapped!

Hi,

If you join the Morini Riders Club, who host this forum, you can see this topic is covered in a recent club magazine (ATG)

Mark

If you have the 26 or 28mm carburettors then the cartune pipes will connect to the balance pipe ferrols of each carb. Best thing since sliced bread after pfaffing about with liquid manometers and seeing the fluid or god forbid mercury, disappearing into the carb and wwith the mercury then desolving the big end bearings. I use the carbtune on multi carb car engines as well in combinatin with a flow meter.

mbmm350s wrote:Hi,

If you join the Morini Riders Club, who host this forum, you can see this topic is covered in a recent club magazine (ATG)

Mark

I have joined, which issue?

Thanks,

Mike

Hi Mike.
Great to hear you are a member.
ATG 357. should be on linein the members area.
Check the carbs the VHBZ 25 HS have the vacuum take off the same as 26mm and 28 mm as Harrymuffin says it's a brass tube at the front left i.e engine side of the slide and typically has a tube between the two carbs.
A basic balance by eye, hand or foot first will get you most of the way there
Mark

Earlier bikes do not have the balance pipes or a connector for them, I remember posting the same question a long time ago and getting lots of advice to use the balance pipes which I simply didn't have. Instead Earlier bikes have a bung hole in the carb to head rubber this is normally blocked with a metal pin with wider ends to keep it secure. To me the fittings for the carb tube that come with the kit seem too large and may stretch the holes making them not gas tight with the bungs. I have experimented with various solutions - football inflators fit onto the fittings but are difficult to get gas tight. I also tried to glue in brass fittings with caps but again was not happy with the solidity? and possibility of material being sucked into the carb. I was remiss in renewing my membership this year - will have to do so now to look at that page - thanks - Duncan

Scottoiler do a connection for rubber inlets which could be used with the 350?
https://www.scottoiler.com/product/universal-spigot/

The early bikes had holes in the rubber inlets plugged with removable pins. Carbtune fittings would then be inserted in their place and once balanced removed and the plugs reinstated. Some of these connecting inlets rubbers did not have the holes and at the time owners were advised to drill a 1/8" hole to plug the Carbtune connectors in and then plug the holes when finnished with a tight fitting machine screw or bolt.

Thanks for all the comments, they have been very helpful. My carbs are old, no balance pipe to use. The bung in the inlet rubbers are about 3mm wide, the Morgan connectors have 5mm thread and will not fit. So I have ordered some 5mm brass adaptors and sealing end caps from Morgan and will carefully drill the inlet hole up to 5mm and install the Morgan connectors permanently with high temperature thread sealant. I'll see how that works out.

Mike

Now with the Morgan connectors permanently installed and new throttle cables attached I have tried to synchronise the carbs today. Managed to get the levels close and slides moving at the same time. It is running more smoothly, great at higher revs, still pretty lumpy at lower revs. Happy to hear any suggestions of what I could try next to smooth things out at low revs too.

Hi
Assume the adaptors are blanked off after use.
Might be worth checking the ignition timing with strobe gun before making further adjustments. Most likely carb related problem is that the mixture is too rich in progression. Did you adjust the idle mixture screws to give the fastest and smoothest idle as the first step in carb balancing and then reduce the throttle stops to balance the columns with an acceptable idle speed.
Mark