silly bollox

freddie1105 · May 29, 2020

just rebuilt my 920 commando, js pistons, rods, valve train ect. without thinking it thru. also fitted 850 base gasket. fired her up. sweet as a nut. sounded beautiful and pulled like a train. stop at a junction after a mile or three. what's that smell? oil burning. long story as short as possible.. base gasket had a tear. didn't think liner size when rebuilding. anyway. scraped as much paper as possible out between barrel and crankcase. forced in green Loctite. left over night. dry as a bone. rode it this morning. oil tight. a lesson learnt and a lesson shared. what a twat! lol

Gadge · May 29, 2020

We've all had similar moments! Nicely recovered.

jbruney · May 29, 2020

We call those brain farts over here. I have lots of gas also...

freddie1105 · May 29, 2020

jbruney said:
We call those brain farts over here. I have lots of gas also...

was a lightly tap forehead against wall moment....sort of

Mwood7800 · May 29, 2020

My case halves were seeping after a rebuild. Pulled head, de oiled crankcase, pulled a vacuum with shop vac and semi air tight tape and plastic. Clean and Super glue in the seams. 4 months now and not a drop. Same trick worked on my lycoming av540

FastFred · May 30, 2020

I bet that goes a bit! I remember going to see a 920 in a damp Halifax 1982 when I was getting into britbikes. He took me on the back and I couldn't believe the torque. I spoke to Roger at RGM a few weeks ago and he said there wasnt much call for them anymore and a std motor is almost too good to mes around with but one day maybe..

storm42 · May 30, 2020

Mwood7800 said:
My case halves were seeping after a rebuild. Pulled head, de oiled crankcase, pulled a vacuum with shop vac and semi air tight tape and plastic. Clean and Super glue in the seams. 4 months now and not a drop. Same trick worked on my lycoming av540

I cannot think of any reason that would not work and be reliable, but, I hope that Lycoming is in an boat and not in the sky.

Fast Eddie · May 30, 2020

The “an 850 is better than a 920” concept is a bit subjective IMHO.

Firstly, for most peoples use in classic circles, I believe it’s totally true. The stock motor is a good performer by classic standards and more than enough for club runs, touring, etc.

Secondly, a poorly built 920 is, obviously, gonna be worse than a well built 850. And back in the day, I reckon quite a few 920s weren’t really up to scratch (using Swiss Cheese barrels, heavy car pistons, etc).

But... a well built 920, that has been built ‘as a package’ is a sweet thing. My Maney / JS 920 is incomparable to a stock 850 in terms of performance, it’s also a much lighter engine unit (by approx 17lbs), and whilst it shakes about at tickover, it’s unfeasibly smooth in use.

freddie1105 · May 30, 2020

Fast Eddie said:
The “an 850 is better than a 920” concept is a bit subjective IMHO.

Firstly, for most peoples use in classic circles, I believe it’s totally true. The stock motor is a good performer by classic standards and more than enough for club runs, touring, etc.

Secondly, a poorly built 920 is, obviously, gonna be worse than a well built 850. And back in the day, I reckon quite a few 920s weren’t really up to scratch (using Swiss Cheese barrels, heavy car pistons, etc).

But... a well built 920, that has been built ‘as a package’ is a sweet thing. My Maney / JS 920 is incomparable to a stock 850 in terms of performance, it’s also a much lighter engine unit (by approx 17lbs), and whilst it shakes about at tickover, it’s unfeasibly smooth in use.

have standard barrels with 920 liners. js 920 package. fcr 35's . runs a dream. love it

Fast Eddie · May 30, 2020

freddie1105 said:
have standard barrels with 920 liners. js 920 package. fcr 35's . runs a dream. love it

Sounds sweet.

What CR are you running? And what cam? And where are the PICTURES ?!?!

freddie1105 · May 30, 2020

FastFred said:
I bet that goes a bit! I remember going to see a 920 in a damp Halifax 1982 when I was getting into britbikes. He took me on the back and I couldn't believe the torque. I spoke to Roger at RGM a few weeks ago and he said there wasnt much call for them anymore and a std motor is almost too good to mes around with but one day maybe..

running in, but just wants to go as soon as you open the throttle

freddie1105 · May 30, 2020

Fast Eddie said:
Sounds sweet.

What CR are you running? And what cam? And where are the PICTURES ?!?!

js1. and as soon as I can work out how to upload the pics I shall post circa boxing day in dining room until in frame and running last week. the missus was happy to see the back of it!!!

freddie1105 · May 30, 2020

I imagine around 9.5 to 1 seems about the general consensus

freddie1105 · May 30, 2020

freddie1105 said:
I imagine around 9.5 to 1 seems about the general consensus

PICTURES???? no need to shout. i'm blind not effing deaf! lol

freddie1105 · May 30, 2020

here goes

trident sam · May 30, 2020

Looks great. can't help thinking though all that motor and just standard (looking ) brakes ?

freddie1105 · May 30, 2020

cnw Brembo master cylinder . I do have a brand new norvil 14" disc and grimeca caliper to go on but the brake seems to work pretty good. will dwell on it sam