Interstate LR tank replacement

Prwith the interstate tank you will have to change the seat,not sure about the longrange tank because that was used with a fastback seat with the ears cut off ,do you have the original twin amals ? a single carb gives better MPG and a single SU gives even more MPG at the expence of top end performance ,if you go for a new tank be aware that the ones from india vary in fit and quality regards nick eviously mark_ross wrote:

Hi AllI have a 72 750 combat roadster, as I live in oz (Australia) I have been thinking of an interstate or LR tank to extend distance between refueling. Does the tank fit without any modifications or do I need to change the seat?

Thanks in advance

Mark

Nerang Queensland Australia

goodluck with finding an original interstate tank make sure you get a steel one ,my glassfibre fastback tank has melted so i now have a roadster tank fitted i really miss that extra gallon !! regards nick

Melted?

If you want to do the full Interstate style Mark, remember the side panels can be changed too. Available new.

I have thought about changing to a roadster since my conversion to a single MK1 Amal and 68 mpg. A very smooth throttle action and the only performance loss is at the very top end. Worth thinking about.

Hi Mark,

Yes, The Hi Rider was for the USA market mostly. Easy Rider.

If you search 'Neil's Norton Notes' you will see at the top of the page, me and my 76 Mk3 Interstate in front of Peel Castle, IOM. It was in a state when I bought it in 1988.

Not been to Queensland but I toured NSW in 2004. Nice to see your new government have done away with much of this Green rubbish. Sensible voters down under!!!!!!!

PS: On twin carbs back then and 45 mpg!

Iv just changed my Commando from twin Amals to single mk1, with standard jets etc. I rode it in the morning with 2 carbs, then in the afternoon with 1.

it was immediately apparent that the bike had lost tourque upwards of 2,500 revs, right where you need it for hills and overtaking. I have to take a bigger handfull compared to befor. It's obvious that will happen as the mixture has to go round two 90 degree bends.

As for mpg, I haven't done enough miles for a definative answer yet but it doesn't look like a vast improvement.

While I still had my twins on when my mate had a single mk1 on his Commando with 280 main jet and number 3 slide, my twin Amals were consistently better, although my engine was freshly rebuilt while his was a bit worn and smokey.

Overall I'm happy with the conversion- reliable tickover and no synchronisation to do, but I think it will only increase the range of a roadster tank from 110 to 125 at best.

Peter, is your Commando an 850? If so, after a lot of trials and error and a word with John Dunn, I found that 3 1/2 slides and a 260 main jet worked best.

If a 750 then I don't know. Of course no two bikes are the same but once you are happy with the set up I'd be interested to know what your MPG is on a run. You might be surprised. I was.

Neil

mine is a standard mk1 850, and I used the left hand carb from my twin Amal setup without changing anything in it ( 260 main jet, 3 1/2 slide ). I was surprised that it worked so well straight away. Starting is one or two kicks, tickover is steady after about 30 seconds of warm up. I used an RGM single carb air filer front plate so it looks standard from the side, and the twist grip action is so much lighter. The Mk1 Amals are such a simple carb to work on and I am familiar with them. I wish I had done this conversation years ago as I can live with the slight torque reduction.

I guess that slide wear will not be to bad as there is more of a constant suck through the carb from the two cylinders, whereas I think the slide rattles backwards and forwards when it feeds just one cylinder.

i will monitor the fuel consumption, but I'm not expecting a big improvement. Even if I got another 10 mpg ( which I think is unlikely ) it will only be another 20 miles on a roadster tank.

At the same time I did the carb conversion I also fitted an RGM Dave Taylor head steady. These two jobs together have transformed the way the bie rides for the better.

Peter, glad it's going well. Looking fwd to the MPG test.

When I found my original head steady plate cracking, I replaced the whole thing with a stainless Norvil item. This meant less engine shakes but a slightly less smooth ride at lower revs.

We agree that the single Mk 1 Amal conversion is a good move.