The AMC God giveth...

Helpful information and requests for assitance and advice
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Re: The AMC God giveth...

Postby peter ranson » Thu Feb 08, 2018 12:17 am

This sounds like a classic case of a blocked pilot jet , the concentric carbs are known for it and can be a right pain in the a%$e to clear because of the pressed in jet. I have even resorted to drilling out the brass jet from the body and fitting a removable jet in the original position which is also used for 2 strokes. the carbs on my commando have been like this for a couple of years now and work fine.

The Monobloc is a much better carb.

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Re: The AMC God giveth...

Postby MalcW » Thu Feb 08, 2018 11:46 am

Hi

Thanks everyone for their input so far. I think that for the sake of originality and long term reliability I will go for a new Monobloc. According to the FW Neill book http://archives.jampot.dk/book/Workshop ... .NEILL.pdf I need a 389/18 with a 390 main jet, slide 4, pilot 20 and needle jet .106. Does that agree with what others are using? Does the price for carbs from the spares scheme include jetting?

Malc

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Re: The AMC God giveth...

Postby 56G80S » Thu Feb 08, 2018 1:45 pm

Replaced my worn out concentric with a Monobloc from the Club; it's fine. A big improvement as the Matchles will now idle.

They come jetted as standard for the particular model - so you need to be aware of that with claarity and also any mods you made which would affect the jetting.

Good service.

Johnny B

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Re: The AMC God giveth...

Postby MalcW » Fri Feb 09, 2018 9:22 am

So, I've ordered a new Monobloc from the spares scheme - but it's on back order. Apparently they can't get hold of a #4 slide. An order was put in to Amal in November, but they just say they will be available 'soon'. I'll have to see if I can coax some enthusiasm out of the Concentric that's on there.

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Re: The AMC God giveth...

Postby leswaller » Fri Feb 09, 2018 2:31 pm

Try Sutton Motorcycles, they may have one in stock
Les
Rules are for the obedience of fools and the guidance of the wise

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Re: The AMC God giveth...

Postby SPRIDDLER » Fri Feb 09, 2018 2:58 pm

leswaller wrote:Try Sutton Motorcycles, they may have one in stock



I think you mean Surrey Cycles, Des. :roll:

https://surreycycles.com/
I poke badgers with spoons.

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Re: The AMC God giveth...

Postby leswaller » Fri Feb 09, 2018 3:02 pm

:oops: Sorry Sprid, yes you are correct, old age and senility are catching up :oops:
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Re: The AMC God giveth...

Postby MalcW » Wed Feb 14, 2018 1:03 pm

Thanks to everyone for their advice, and to Leswaller and Spriddler for their suggestion for locating a #4 slide. But I don't need to bother, as my new Monobloc arrived this morning, all jetted up and raring to go. And a beautiful thing it is too. Can't wait to fit it.

Malc

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Re: The AMC God giveth...

Postby Expat » Wed Feb 14, 2018 2:47 pm

MalcW wrote:Thanks to everyone for their advice, and to Leswaller and Spriddler for their suggestion for locating a #4 slide. But I don't need to bother, as my new Monobloc arrived this morning, all jetted up and raring to go. And a beautiful thing it is too. Can't wait to fit it.

Malc



That’s how I felt when it arrived. Made such a difference, you will love it, bike ticks over a treat now, like a Singer. :)

Steve
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Re: The AMC God giveth...

Postby MalcW » Mon Feb 19, 2018 9:12 am

So, I've started fitting the Monobloc to the Model 31. Firstly, I had to move an ugly cartridge oil filter that someone previous had fitted, as it fouled the Monobloc's float chamber but that was a job I was going to do anyway. One thing though is that the clearance between the carb's cable adjusters and the frame tube is very tight, especially for the choke adjuster. Is this normal?

Malc

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