1955 G3LS Problem

emilios · Post by **emilios** » Thu Mar 05, 2009 7:05 pm

Hi, I am new in this Forum, and I though there would be someone here that could help me.

I have fully restored a 1955 G3LS four years ago, but there has always seemed to be a problem with its Top Speed (I mean after it was restored at a specialist mechanic). It cannot go faster than 55-58 mph, whereas normally this model's top speed is 75-80 mph, and 55mph its cruise speed. I do not remember what its engine's sprocket size is, but I definitely know that the gearbox's sprocket is 16 teeth.

It's been 3 months since the last time I started the engine up (I know..it's too long). And today, when I did start it up (first kick start), there was some oil dripping from where the exhaust pipe meets the engine head. Is this because it's been 3 months since its last start up (and the oil had gathered at the bottom crankcase)? Or, is there a connection with the problem that I had with its speed (and I have to rebuilt the engine head)?

If this is not obvious, I am not a mechanic but I do like to know what's wrong with my bike...and try to fix it, if I can...

Thank you in advance for all of your help...

rex.webb · Post by **rex.webb** » Fri Mar 06, 2009 7:20 am

Hi to aNew Boy.
After 3 monthe the oil has drained into the crankcases.The engine is now trying to pump it back and some is getting past the rings.This is coming out the Exhaust.Do nothing till you have given it a run and the oil has pumped back to the oil tank.
Ride with Care and Live Long.

emilios · Post by **emilios** » Fri Mar 06, 2009 8:49 am

Yes but what about speed problem?

SPRIDDLER · Post by **SPRIDDLER** » Fri Mar 06, 2009 9:15 am

Welcome Emilios
Not fast enough?
...Are you sitting comfortably??
Is the speedo accurate?
When I first had my '54 G3LS the speedo read 12mph slow at 20, and 15 at 40. (Couldn't understand why it handled so badly taking roundabouts at 25).
Is the carb set up correctly?
1 1/16" bore
Main: 210
Slide: 3 1/2
Needle pos'n : 3rd groove down from top.
Try closing the choke when riding on full throttle (!) - if speed increases main jet may be too small or poss blocked/restricted.
Is fuel height in float chamber too low (weak).
Fuel level is the 'dot' below the letters 'M' and 'A' of the word 'AMAL' on the float chamber end plate (on a Monobloc).
Is the timing correct and the auto advance advancing or is it stuck at the starting (retarded) pos'n? Is the exhaust very blue around the bend? (Poss running too retarded and overheating).
Points set correctly?
Valve clearance?
Are the cams lined up correctly? - Even specialist mechanics can get this wrong.
Cams should be marked H or HL and numbered 1,2,3. You should have lined up No.3 on inlet and 2 on exhaust
(Cam info courtesy ITMA).
75 - 80mph seems 5 to 10mph optimistic to me though - Anyway, if you go any faster you'll be wanting 12v lighting!!

Good luck!Edited by - SPRIDDLER on 06 Mar 2009 09:38:29 AM

orbinrangle · Post by **orbinrangle** » Fri Mar 06, 2009 10:01 am

At the risk of being indelicate, I do find my 18S does not like to go much over 70mph although it does cruise nicely at 50mph. But then I don't want to thrash it and I am aware that I'm 6'4" and weigh a little over 17 stone. That weight equals two up in a lot of cases. So I don't expect it to go quite as well as most. Is weight a consideration?

aobp11 · Post by **aobp11** » Fri Mar 06, 2009 10:46 am

Gearbox small sprocket is 16 teeth all models. Engine sprocket 21 for 18S but 18 for 350 cc road models. So maybe you have the wrong engine sprocket. These data are in the spares list of that year.
Albert

Merlin · Post by **Merlin** » Fri Mar 06, 2009 10:55 am

I consider 55mph quite adequate for my G3LS since when I am out I don't intend to go any where fast anyway.

pto · Post by **pto** » Fri Mar 06, 2009 11:47 am

The fact that your bike will only do 58 mph means you have a problem that needs sorting out even if you are happy to travel at around 55mph,otherwise who knows what damage may be done to the engine. Go through all the basic checks as advised, one long shot is that you may not be getting full throttle opening.

mikeydpippin · Post by **mikeydpippin** » Fri Mar 06, 2009 10:13 pm

Interesting as i'm running my G3 in at 35-40 mph and wondered what top speed to expect.I thought maybe 55-60 but not 70+.
But hey if it's speed your after go for a hyabusa.
If it's a quality ride and memories try a G3.
A bit like me i'm aged now and built for a long and pleasurable ride not a quickie.

Merlin · Post by **Merlin** » Fri Mar 06, 2009 10:28 pm

A bit like me i'm aged now and built for a long and pleasurable ride not a quickie.
Well said as the pop song says "Give me a man with slow hands" don't remember the title sung by a girl band.