1955 G3LS Problem

emilios · Post by **emilios** » Sat Mar 07, 2009 8:54 am

Thanks guys...i really like pleasurable ride not a quickie but lately a see power problems on hill...it doesnt have that power to push me on hills....

AJS650 · Post by **AJS650** » Sat Mar 07, 2009 9:50 am

quote:
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.

itma · Post by **itma** » Sat Mar 07, 2009 10:00 am

Riding an old bike is a state of mind as much as a state of tune.
I would look at your riding technique as much as anything else.
I would sugggest that you use the gearbox a little more thoughtfully, unless you are 20 stone and living amongst the hills of Wales I can't see why you have a problem.
I have crossed the Pyrenees on a 350 and traversed France on the same bike, I did not feel the lack of power on hills.
I also think that you are being a bit optmistic about you bikes top speed.
Your original question is sadly almost unanswerable because there are so many variables to cover.

As has already been pointed out your problem could be as simple as the wrong speedo or speedo drive.

[and take no notice of Anne she is a saucy hussey just out to lead old men astray]Edited by - itma on 07 Mar 2009 10:02:45 AM

AJS650 · Post by **AJS650** » Sat Mar 07, 2009 10:03 am

little ol me.........

emilios · Post by **emilios** » Sat Mar 07, 2009 3:42 pm

i do have wrong speedo...i use MZ speedo for now...just to close the whole...so i hope that speedo is wrong...i will try bike speed next to car...
But what to do with power problem....i really have power problem cause in last trip with a friend who has the same bike...i stay behind through small hills..
So what do i have to check first before taking head off and check valves,valves guides and piston rings?

crawsue · Post by **crawsue** » Sat Mar 07, 2009 6:24 pm

Read Spriddler's post above,just go through each check one at a time.Most likely causes of power loss are carburetor set up wrongly...or wrong carb.Timing incorrect and/or advance /retard not working.Take sump plug out and make sure that cranckase is not full of oil.If engine starts easily and ticks over OK and no "bad" noises from the engine then it should be something simple....just attack them one at a time.I assume that it is not burning oil....signifying that it needs a re-bore? Try Sprid's choke test 1st,could be you are running with the choke "on"Edited by - crawsue on 07 Mar 2009 6:25:32 PM

Duncan · Post by **Duncan** » Sat Mar 07, 2009 10:49 pm

In addition to the above advice , mine would be to start off by checking the engine basics first (spark plug, points gap, timing, valve clearances, carburettor clean) against the manual specification so that you are confident that they are not the culprits, all of this can be done without having to get heavily involved in dismantling the bike.

Then start thinking laterally what else could reduce power (incorrect use of A/R lever, tight decompressor cable, choke slide not pulled right up, is cylinder compression down) or hold the bike back (binding brakes, dry tight drive chains, condition of the wheel bearings etc.) It may be worth cleaning the brakes out as I have had an riveted shoe brake a small section off and wedge between the shoe and drum.

For what it is worth my 59 G3L measured on a digital bicycle speedo is perfect at 45mph, happy at 55mph, and had it at 60/65mph, if I am feeling particularly cruel and the hill is long enough 70mph+ may come up but it is not a realistic speed for every day use. The engine is what could be called “soft” as the compression is down and I do not need to use the decompressor to or bother taking it over compression start it.

Youngster · Post by **Youngster** » Sun Mar 08, 2009 2:30 am

Hi, just a question,

If the bike was fully restored 4 years ago, how come you now have an MZ speedo?

crawsue · Post by **crawsue** » Sun Mar 08, 2009 1:16 pm

" Just a question" for you,Ian,2:30am Saturday night,on the forum,were you just going out or just coming home?!!!!!!

Branston · Post by **Branston** » Sun Mar 08, 2009 2:38 pm

Your 350 should comfortably reach 60mph with no sweat. They will do 75 flat out but that's thrashing the poor old girl!
eng sprocket gearing (should be 18T)a 17T (350 sidecar) would give about 58mph
Check Ign timing
Pushrod adjustment
Further down the line you could see if your piston rings are still in one piece. I once discovered totally shattered comp rings in a 350 I was using daily & only discovered them when I stripped the bike to cure oil leaks- which may well have been caused by the additional crankcase pressure due to the broken rings!
People do indeed get greatly confused by Matchless single camshafts. Yours should have 3 numbers dots on each and should have an H stamped on them.If they are 2 dot ones they are earlier and of lower lift.(Settings are different for this type)
Assuming H stamped cams:Set the inlet cam first with the dot on the timing pinion at 10 o'clock, then rotate the engine clockwise so the dot is at 2 o'clock
then line up the exhaust cam.
Inlet Cam is Mark 3
Exhaust Cam is Mark 1
My money though is on you discovering a 17T eng sprock!
Cheers
RJG