Hello, I just bought a 1955 James Captain, it’s a surprise for my 84 year old Father he had one back in the day, I don’t pick it up til the weekend but I was hoping for some advice on a running issue  that the current owner has mentioned, he said it starts easily and rides but won’t rev fully, I’m not that familiar with 2 strokes so thought I’d ask on here for any tips on where to start, thanks Mark.

Edited March 4, 20197 yr by Mark9

Things that could stop it revving out;

All the usual things, like;

timing not right,

Blocked exhaust, restricted inlet, (blocked air filter etc)

Blocked jet

Not enough fuel getting to the carb

Weak spark colappsing under load

or something that I've forgotten, good luck, bike looks cool.

 

As above could be any number of things but I would start with fuel flow -  Dump the existing fuel, rinse any crud out from the tank, strip and clean the carby,

Here's a link that might help.

https://www.motorcycleclassics.com/mc-how-to/amal-concentric-carburetor-overhaul

Cheers

 

Hi Mark, the carburettor fitted is a Villiers best place for all things Villiers is https://villiersservices.co.uk .Normally a well set up villiers carb gives good running so probably nothing too wrong best to check all the things already mentioned also their is a bakelite plug lead to coil connector piece that can be troublesome but if ok works fine.

I would clean the air filter, clean and airline the carb pay particular attention to the needle which sits on a spring and is adjusted with a screw from the top, plug cap and plug, check timing and spark. Good luck the bike looks great.

Thanks for the replies all, I pick the bike up on Sunday so I’ll get started on it then, you’ve given me some good angles of attack :)

Bear in mind that these long stroke motor don't exactly rev, but try it down hill and if it will reach past 45 then the problem is probably fuel

I found 2 issues,

1. The needle should be set at 1.95 inches, it was over 2 inches.

2. The points gap was too small

I fixed those and now it goes well, thanks for your help, cheers Mark.