Beast and the carb

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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spookefoote1956
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Re: Beast and the carb

Post by spookefoote1956 »

Interestingly though Spriddler may have something regarding blockage. If you remember I had a problem with a fuel tap which sheared. I removed it and also cleaned out the tank. However crap could have remained and got through to the jets. I have stripped the carb down to clean it and also fitted an in-line filter as an extra filter. I'll let you know how that goes.
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spookefoote1956
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Re: Beast and the carb

Post by spookefoote1956 »

clanger9 wrote:Good, now you are getting somewhere! :)

Don't mess with the shim kit, there is only one correct float level for an Amal and it sounds like yours is right.
Timing seems OK from what you describe. Now onto the fuel mixture...

When it fires, is it 8-stroking (firing every other compression)? Does it produce black smoke? Does it respond at all to the throttle, or just pop-pop-pop-stop?
pop pop pop stop
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
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spookefoote1956
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Re: Beast and the carb

Post by spookefoote1956 »

I also have a blanking plug in the top of the carb.
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clanger9
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Re: Beast and the carb

Post by clanger9 »

OK, as Spriddler said it sounds like it's running on the tickle then stopping due to lack of fuel. i.e lean.

- Screw the pilot air screw in a bit. 1 or 1 1/2 turn out will richen the mixture slightly (and help it to start).
- Check the pilot jet is clear (sounds like you're already on to this)

Hopefully it'll start now...
1989 Moto Morini Dart 350
1993 Ducati 750SS
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spookefoote1956
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Re: Beast and the carb

Post by spookefoote1956 »

Stripped the carb, put it back together, altered the air screw, pop pop pop stop.
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
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spookefoote1956
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Re: Beast and the carb

Post by spookefoote1956 »

Any thoughts on the best way to clean the pilot jet. Youtube shows bits of wire but I've been told it can damage the jets.
Hail Joe Lucas ............ Prince of Darkness!
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"Creativity is your intelligence having fun" Albert Einstein
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clanger9
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Re: Beast and the carb

Post by clanger9 »

:headbang:

That's a strange one. I wonder if the pilot is blocked? I take this this is a new carb and it's not run before?
fig_27_28_562x460px.png
The pilot hole (7) needs to be clear. I definitely wouldn't use steel wire, though you should be able to carefully poke a thin stand of copper wire through there without causing any damage.
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1989 Moto Morini Dart 350
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spookefoote1956
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Re: Beast and the carb

Post by spookefoote1956 »

Brand spanking new.
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"Creativity is your intelligence having fun" Albert Einstein
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Re: Beast and the carb

Post by SPRIDDLER »

spookefoote1956 wrote:Brand spanking new.
I've heard of several instances of blocked Pilot jet/drillings on a brand new Monobloc. Swarf seems to have been left behind after manufacture.

I assume that you have actually removed the brass Pilot jet and checked that it's clear (one small
hole each side and one at the end in the centre) ?

Forcing aerosol brake or carb cleaner or WD40 into the pilot drillings using the plastic straw should give you a clue as to any serious blockage although a partial blockage may not be so obvious if you don't know how it should be.
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spookefoote1956
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Re: Beast and the carb

Post by spookefoote1956 »

I've cleaned the pilot with Wynn carb cleaner and it was a little more responsive. I'll update as and when. Thanks for all the suggestions.
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
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