Mikuni

[martymoose]

I reckon you're on the money there Lothar. An under performing condenser will definitely affect spark. Always fit new points and condensers at the same time on the service schedule for all the old cars I used to service. My SF2 had a condenser fail, no spark... Rode home on 1 cylinder

 

[Tippie]

What are the signs of it, please? black, maybe even wet spark-plug? could be indeed pointing to a spark problem rather than a carb problem maybe...?

Easy to fault find that. Swap wires at points and swap HT leads to sparkplugs and see if the problem swaps sides.

 

[Paul Marx]

What are the signs of it, please? black, maybe even wet spark-plug? could be indeed pointing to a spark problem rather than a carb problem maybe...?

Black plug Lothar partly due to oil coming down the guide, the inlet valve is a bit oily. Problem present before and after putting on new carbs.
For a little while now, if run at constant throttle, it hesitates a bit on pick up and then ok.
Black plug has been like that since 1993 but without hesitation resembling plug fouling. That appears after having put new exhaust tubes and banana box on a couple of years back.

I've still managed to put 130 000 km on the bike.

Paul

 

[MarnixSFC]

I know it’s not a popular thing to say here, but in my view it doesn’t make sense to mount those over complex carbs that have a hard time with the twin’s vibrations/pulses.
Just look at the exploded view of the and see yourself dealing with issues on the side of the road. I had Mikunis on my CND, and all issues that I had with the bike were inside the carbs with synchronisation nut coming loose and one of the exquisite rubber mounted float needle holders failing.

I made my 250.000+ km white SF2 happy with a fresh set of PHFs.

If you fancy modern technology, then start with electronic ignition.

Marnix

 

[Paul Marx]

I know it’s not a popular thing to say here, but in my view it doesn’t make sense to mount those over complex carbs that have a hard time with the twin’s vibrations/pulses.
Just look at the exploded view of the and see yourself dealing with issues on the side of the road. I had Mikunis on my CND, and all issues that I had with the bike were inside the carbs with synchronisation nut coming loose and one of the exquisite rubber mounted float needle holders failing.

I made my 250.000+ km happy with a fresh set of PHFs.

If you fancy modern technology, then start with electronic ignition.

Marnix

Thanks for the advice Marnix.
Paul

 

[ksoholm]

Spend the money on a rider training school?
And weight watchers?
Best go fast recipes.

 

[Paul Marx]

Spend the money on a rider training school?
And weight watchers?
Best go fast recipes.

Don't need to.
I'm slow.
Paul

 

[Alzero]

Why spend on titanium and carbon fibre when you can just take a big dump before the race!

 

[chrisk]

Why spend on titanium and carbon fibre when you can just take a big dump before the race!

Both worthy of bragging rights with your mates too.

 

[Tippie]

Don't need to.
I'm slow.
Paul

Make up a manifold to use a single carb?

 

[chrisk]

I want Paul to do the M carb route, because I’m interested to do it too

Carn Paul, bite the bullet

 

[Paul Marx]

Make up a manifold to use a single carb?

An SU à la Commando would be interesting.
Paul

 

[chrisk]

An SU à la Commando would be interesting.
Paul

Are you riding a Mini Minor?

 

[sfcpiet]

An SU à la Commando would be interesting.
Paul

Yeah, they'd match your ignition points nicely, just as outdated... they were the carb of choice for the Norton mob because they were probably about 6 shillings apiece at a breakers' yard. But possibly still an improvement over a clapped-out pair of Amal Concentrics.

If you're aiming for economic reliability, go for the budget Mikuni VM. They're still available up to 44mm, loads cheaper and physically smaller, therefore easier to install than the RS, TMR or FCRs, with none of their drawbacks.

piet

 

[Paul Marx]

Yeah, they'd match your ignition points nicely, just as outdated... they were the carb of choice for the Norton mob because they were probably about 6 shillings apiece at a breakers' yard. But possibly still an improvement over a clapped-out pair of Amal Concentrics.

If you're aiming for economic reliability, go for the budget Mikuni VM. They're still available up to 44mm, loads cheaper and physically smaller, therefore easier to install than the RS, TMR or FCRs, with none of their drawbacks.

piet

A local friend of mine has an SU on his Commando. He did a round the world trip on it and it's still going strong.
It depends what you want a motorcycle for.
Paul

 

[mauricejota7604]

Funny thing I got a pair of new 32mm Amal premiers with my 850 Commando and thought they would be better on the bike than the worn out originals, I fittd them and the bike ran terribly, I had to get some inside info from an old brit bike expert then change every single component withing the carbies to suit the Commando engine FFS it runs well now though!!

 

[Paul Marx]

Funny thing I got a pair of new 32mm Amal premiers with my 850 Commando and thought they would be better on the bike than the worn out originals, I fittd them and the bike ran terribly, I had to get some inside info from an old brit bike expert then change every single component withing the carbies to suit the Commando engine FFS it runs well now though!!

The problems with Amals would appear to be that they wear quickly.
Paul

 

[pf1]

The problems with Amals would appear to be that they wear quickly.
Paul

They were perfectly matched to the engines of the time then. Although I loved my Commando there wasn't much of it that didn't fall apart quite quickly.

 

[chrisk]

Although I loved my Commando there wasn't much of it that didn't fall apart quite quickly.

I found that hilarious.

I was talking to a bloke while strapping down his latter incarnation of Norton.

He said basically the same thing…

 

[RJS]

I had 4 Commandos - 2 750s and 2 estart 850s. Contrary to what most people seem to believe my starters actually worked. In fact on one the kick starter almost fouled the rearsets I installed so I took off the kick start lever. I may be looking back through rose tinted glasses but the only problems I recall are ones I inflicted on the bikes myself.