Single mk.1 Amal or Mikuni ?

Hi,

I bought a kit from RGM earlier this year. 34mm Amal MkII with K&N air filter, and manifold, £220 + VAT. I wish I had done it years ago.

I have an 850MkIII

Tony

Hello,

the main problem with Mk1 amals and I also assume Mk2's is body wear due to the slide being made of the same material. Within 10,000 miles and the carbs will be nackered re slow running and tickover. Solution is to have wear removed from the bodies by machining and then have the slides sleeved with brass. Mine are rubber mounted and have bore to slide clearance of 0.001'' and are still working fine after 10,000 miles and are looking good for many more thousands. Alternatively fit Mikuni's or Kehin's which are made properly in the first place.

Simon.

Hi Simon,

The old Mk 1's were (I believe) made of Mazak and yes they did wear very badly. The Mk 2 I have does not look like the same metal and the slide isdefiantlynot. I know a few people whohavea good few thousand miles with a Mk 2 and they are still working well. Remember the Mikuni is just a licenced copy of the Amal Mk 2.

Regards

Tony

The Mk 2 Amal has a much larger diameter slide and is therefore supported better when moving. it is teflon coated as well. The Mikuni has a chrome plated brass slide and works well though all these single carb conversions seem to fade as you approach the upper rev range. They are brilliant for normal running up to about 75mph. I'm currently toying with twin Kehin flat slides from jsmotorsport.com in the USA these come with bespoke needles for Commando, rubber mounted manifolds, filters and lower cables. for $445 by the time you add p&p, tax and convert to sterling it works out at just over £300 The guys in the USA are raving over these carbs and the price is good comparing with what the options are over here.

I have measured the Mk1 slides I have in the garage (about a dozen) they have only worn about 1 or 2 thou despite looking worse than that. It's the bodies that wear and they weren't that good a fit when new. Simon's machined slides at 0.001 are the way ahead. I'm about to bore my old bodies out and fit Mikuni slides. There's not much meat on the bodies to start with.

Hi

I have had the amal mk2 conversion for a couple of years. The carb needs to be supported insome way, I have cable ties looped under it, from the frame tube. I carry a spare rubber manifold as they can fail and strand you in the strangest places (last bike out of the Santander ferry when it went and it's a long push up and out of the boat).

Get one of the stay up floats as the standard can be affected by modern petrol (had one go so far).

Keep and eye on the large drain bolt on the bottom of the carb, they can vibrate out and leave you stranded in other strange places (left talking to stylists in a ladies hair dressers that I came to a halt by while the better half got a new part to rescue me).

Don't overtighten the jubilee clip on the rubber manifold as it can bite into the rubber,tear it and you need another manifold.Under tighten it and the carb will fall off the bike just when you don't need it to (overtaking a volvo on the bypass).

Must be a better way of doing it....