The story of this OSSA is posted up in introductions...I am in the process of bringing this back to life.

 

Unfortunately gas was left in the tank for a very long time and when I pulled the Amal 627 off to rebuild it was filled with goo...I'm assuming resin from the Fiberglass tank?

I cleaned everything in a dip type carb cleaner and it looked pretty good. I put it all back together and using an auxiliary fuel tank I turned the petcock on tickled the carb and gave it a few kicks. Nothing. I gave it a quick shot of starting fluid and she fired up but bogs badly when I roll the throttle on. It seems like it wants to run on full throttle but bogs from partial to mid throttle. It seems like it is running out of gas if I try to hold partial throttle.

 

Is this a float problem or blocked pilot jet  or something else? Any suggestions?

Not sure what your carb problem is, just thought this link may be of help as it lists the jets/slide etc for a 627/416 Amal which is what was fitted to a 71/72 MAR according to this site.

 

http://amalcarb.co.uk/carbspec/carburettor/spares/id/5503/

Here's the jetting specs for the Amal 627/422 as fitted to the 73/74 MAR, apparently.  Note that slide and pilot are richer than 627/416 and main leaner, needle remains the same at 106.

http://amalcarb.co.uk/carbspec/carburettor/spares/id/5504/

 

it is very hard to get the goo out of the pilot circuit and your symptoms do sound like that might be the problem

it is very hard to get the goo out of the pilot circuit and your symptoms do sound like that might be the problem

 

 

Thanks, I was afraid of that...I might take the carb back off and try and soak it longer. If that doesn't work I'll probably look for a replacement.

we had similar running symptoms as you. does yours have a decompressor? ours was not fully coming out as the top of it hit the front pipe! only needed to come out a tad more for it to run good. also the carb float bowl gasket was gone on ours so that helped..

If it revs out yet bogs on the first 1/4 to 1/3 throttle is likely, as already said the pilot.

 

Stale fuel causes all the horrid goo and once it's dried on it's a bugger to shift, carb cleaners don't seem to touch it.

You might get some joy scraping and poking at it, but remember Amals are made from some sort of magnesium alloy and are very soft, so get damaged or wear easy.

 

Depending on what you plan, it might be worth investing in a new one.

New Amals are available for originality.

Mikunis, OKO's and Dellortos are better if you want it to perform and aren't restricted by rules.

 

I've had my Mk3 running well on a VM26 and even better on a 26mm VHST.

I think I have all the jets and setting written down somewhere if needed.

 

Edited July 1, 201511 yr by goudrons

If it revs out yet bogs on the first 1/4 to 1/3 throttle is likely, as already said the pilot.

 

Stale fuel causes all the horrid goo and once it's dried on it's a bugger to shift, carb cleaners don't seem to touch it.

You might get some joy scraping and poking at it, but remember Amals are made from some sort of magnesium alloy and are very soft, so get damaged or wear easy.

 

Depending on what you plan, it might be worth investing in a new one.

New Amals are available for originality.

Mikunis, OKO's and Dellortos are better if you want it to perform and aren't restricted by rules.

 

I've had my Mk3 running well on a VM26 and even better on a 26mm VHST.

I think I have all the jets and setting written down somewhere if needed.

Thanks...I had success today! I was able to clear the pilot jet and she started up and I was able to get it to idle....now as for the gas tank, I have it cleaned out and am going to try some Caswell's to line the tank with.

 

Norton Mark III?

Mk3 MAR

I got it running! here's a short video...sorry for the poor quality I was trying to hold the phone while starting  the bike.

 

http://vid248.photobucket.com/albums/gg190/twstm/20150701_193854_zpsnq7hluam.mp4