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hulmie

Any Ideas What's Going On

31 posts in this topic

Just finished rebuilding my 24tes New seals, bearings,rebore piston and was advised to go for a new amal now I have two new problems, first she's an absolute pig to start tried flooding it with the tickler no choke then with choke then after loads of kicks she'll fire then on to fault 2 it will tick over for about 10 seconds then it will rev to the max and can't be stopped on the kill switch only using the gearbox and brakes, it's got new gaskets on the inlet and a new oring on the carb, so now I've dropped on the original amal monobloc and with one tickle fired up with two kicks it runs ok but it's really wooly of the bottom, does anyone have any ideas is it me or is this new carb a piece of ****

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Don't want these Ads? Why not sign up as a Trials Central Supporter.

Don't pretend to know anything about Greeves; that said its still a 2 stroke.

With all  the good work you have done it would appear the new carb is a

piece; if as you say it's "wooly" off the bottom I suppose its rich/lean?

I am not a fan of Amals as I have no luck and no patience some folks have

good luck however.

 

Best of luck

Larry

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My Montesa 315r did the same after a complete engine re-build. After 1 month of stripping and cleaning the carb it turned out the engine builder had left the crank seal out. New one in and was fine !

 

       Good luck with it buddy.

 

       Craig.

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Thanks Larry and Craig I'll have another crack at it this weekend, its definitely got no problems with the seals I did them my self, I just can't work out why it runs ok with the old carb but goes nuts with the new un

Andy

Edited by hulmie

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It sounds like maybe the new carb is not getting much fuel (float valve)?

Not familiar with tickler & a choke,  do you see fuel coming out of the weep hole when 

the tickler is held down? If so then cover the hole with your thumb to get fuel in the proper place.

My experience with Amal concentric's ; you must be careful when tightening the top as it 

is easy to warp things and then the slide hangs up.

Be careful with your fresh rebuild.

Larry

 

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Sounds like the slide is either in backwards or not closing all the way. I would not start it again until this is resolved. Good Luck.

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Thanks Larry and Craig I'll have another crack at it this weekend, its definitely got no problems with the seals I did them my self, I just can't work out why it runs ok with the old carb but goes nuts with the new un

Andy

 

This is a very good thing as youve pin pointed the problem.

Go through the new one piece by piece im sure its there somewhere!

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Just finished rebuilding my 24tes New seals, bearings,rebore piston and was advised to go for a new amal now I have two new problems, first she's an absolute pig to start tried flooding it with the tickler no choke then with choke then after loads of kicks she'll fire then on to fault 2 it will tick over for about 10 seconds then it will rev to the max and can't be stopped on the kill switch only using the gearbox and brakes, it's got new gaskets on the inlet and a new oring on the carb, so now I've dropped on the original amal monobloc and with one tickle fired up with two kicks it runs ok but it's really wooly of the bottom, does anyone have any ideas is it me or is this new carb a piece of ****

Hi,

 

Sounds very much as though your new carburettor has major problems, I suffered with similar problems when a replacement carburettor had internal airways blocked with a thin skin of alloy - obviously an inspection failure of the quality control department during manufacture. I had foolishly bought it at an autojumble - so the sole recourse was to the dustbin..............

 

You say the main problem with your old carburettor is 'woolly of the bottom' which I assume means it won't pick up cleanly from low speeds.  I would look at the taper on the air screw (on the side of the carb. with a spring so that you can set it and it will stay).  Quite often, over time, the taper end of that screw gets worn against the hole that it operates in, and forms a ridge in the taper.  Dress the ridge off with a fine file or emery paper and the problem may go away.

 

On my TES I used an interesting american tuning spark plug with a clear glass body in place of the normal ceramic, which meant that at low revs you could see the colour of the flame inside the combustion chamber, you can set it to rich or choked - when the flame is bright straw, yellow almost, then gradually weaken off (screw in) the air screw until the flame loses its bright colour and settles to a light blue or colourless. That gave ideal pick-up from low revs - as long as you remembered to swap the tuning plug for the correct spark plug when tuning was done.  Also if no amount of adjustment on the air screw made any difference you could instantly know to look elsewhere.

 

Just a thought...........

 

Have stirred up the old grey matter and remembered it was a 'Gunson Colourtune Kit' and they are still available on eBay for less than £25 - does that help?

Edited by laird387

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Thanks liard i'll have look for that, took it to its first trial today and had a play with the air screw and found it would run great with the air screw all the way in, so does this mean I need a bigger pilot jet? I checked the plug after the first lap and it's a nice dark brown colour so mixture seems ok, Now may have found another fault, the first lap it ran great stopping and walking the sections but the rest of the laps it was getting really hot really quickly and was pinking/knocking under load so I'm thinking the timing may be too far advanced.... Any ideas anybody

Andy

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If it's running that hot, timing is too far advanced - especially if it's pinking under load.

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That's what I was thinking i'll have a play with the timing for next time, have you got any ideas about the pilot jet? but other than that it was a blast to ride, it turns so much tighter than my beamish

Edited by hulmie

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By the look of the spark plug the mixture looks ok if anything slightly rich which is making me think timing as its getting hot really quick

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By the look of the spark plug the mixture looks ok if anything slightly rich which is making me think timing as its getting hot really quick

Hi,

 

The 'look of the plug' is one of the most misunderstood elements of tuning - you need to be qualified by years of experience to be able to actually 'read' a plug by its appearance - so check by every other means at your disposal before relying on plug colour - which is about as reliable as tea leaves are for predictions................

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Andy, if it runs better with the air screw all the way in, it very certainly needs a larger pilot jet, at present you have zero

adjustment left.

If the timing is correct; one would think lean mixture, go bigger on the pilot and this should help the whole mess. 

Good luck (don't fry the new build)

Larry

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