Laser 50 Plane Olde Bargain.

[David Davis]

I bought a Laser 50 from A Plane Olde Bargain, thank you Claire Williams! I squirted two-stroke oil into it through the glow plug hole, Bardahl "Don't Start Without Us," and discovered that even the glow plug supplied with the engine, an OS F, actually worked! Compression was excellent and this afternoon, I checked the valve clearences, they were miles out! Having sorted out the valve clearences, I installed it in the test stand and it started straight away. On the standard little silencer with a piece of copper by way of an exhaust extension it was rather noisy on a 12x4 prop so I robbed a silencer from an unemployed Laser 70 and fitted a 12x6 prop which produced a better, quieter sound.

 

The 45, 50 and 62 were identical externally, I have a 62 in the nose of the Big Guff in my avatar. Does anybody know the size of the bore of any of these engines so that I can be sure of its size? I plan to run it in next year's Coupe Des Barons but capacity is limited to 0.56 cu. ins for four-stroke engines so the 62 would be ineligible.

 

Must find my British allen keys and order some grub screws from Model Fixings.

 

Sorry about the quality of the second picture.

 

 

[Jon H]

Unless my eyes deceive me, that is a 61 and not a 50. 

 

[David Davis 2]

How do you tell the difference?

 

[Jon H]

They just look different. On the bright side though, the 61 was really very powerful for its size. 

[Jonathan W]

If you want a good 56 4-stroke, I can recommend the Saito 56. Nowadays replaced in the Saito range by the 62, but you should find one secondhand easy enough. I have a 56 in a 72" Astro Hog, which is a draggy and heavy lump but surprising how well it is hauled along by the little Saito.

[David Davis]

11 hours ago, Jon - Laser Engines said:

Unless my eyes deceive me, that is a 61 and not a 50. 

 

 

I don't think that my engine is identical to the one in your picture Jon. Mine has flats machined into the cranckcase just below the cylinder. It has nine fins on the cylinder like the one in your picture.

 

4 hours ago, Jonathan W said:

If you want a good 56 4-stroke, I can recommend the Saito 56. Nowadays replaced in the Saito range by the 62, but you should find one secondhand easy enough. I have a 56 in a 72" Astro Hog, which is a draggy and heavy lump but surprising how well it is hauled along by the little Saito.

 

Jonathan W, I have at least seven four-strokes which could be used in La Coupe Des Barons, I just wanted a Laser 45 or 50 so that I could run a British four-stroke in the competition.

 

I took some close ups early this morning. It needs a clean doesn't it!

 

 

[John Rickett 102]

If it helps, here's a picture of Laser 50 and 61 all bought around 1992. The outer ones are the 50s.

 

[brokenenglish]

David you've got your engines mixed up.

I have a 45 and a 62, and the front bearing housings are parallel profile, not tapered like the one in your picture, i.e. as shown in John Rickett's photo above.

Your engine is bigger and/or later than you think.

[Jon H]

2 hours ago, David Davis said:

Mine has flats machined into the cranckcase just below the cylinder

 

Ah, then its a 75

[David Davis]

Thank you gentlemen for your replies.

 

It looks like I've acquired a 75 which is of course far too big for La Coupe Des Barons but I have several Japanese and Chinese engines which will be suitable.

[Jon H]

If its this hard to work out the engine size the judges will never know 😉 

[Engine Doctor]

Dave look on Scepter Engine tests . They have tests on 62, 70, an 75 to give bore and stroke . Not much help for Coup de Barron class but you will know what you have. 

5

In case you didnt already know Laser cant supply parts for these older models apart from valve springs which are common to some current engines. Bearings are easy to get and piston rings are available fro Gaviscool on ebay and recommended. Unless severly abused or neglected  they are bullet proof engines, overengineered and will/ should last for years. 

[David Davis 2]

2 hours ago, Engine Doctor said:

Dave look on Scepter Engine tests . They have tests on 62, 70, an 75 to give bore and stroke . Not much help for Coup de Barron class but you will know what you have. 

5

In case you didnt already know Laser cant supply parts for these older models apart from valve springs which are common to some current engines. Bearings are easy to get and piston rings are available fro Gaviscool on ebay and recommended. Unless severly abused or neglected  they are bullet proof engines, overengineered and will/ should last for years. 

 

It appears to be a sound engine just requiring a little cosmetic attention regardless of its size!

[John Wagg]

Maybe this will be useful but no matter what I do I can't get it the right way up. :-

 

[Ron Gray]

Your one was for when it's mounted inverted.

 

Edited June 14, 2023 by Ron Gray

[John Wagg]

Thankyou Ron. I tried a few times to right it but had to give up. This came with my 62 (1992) which isn't in the list ??.

[Paul De Tourtoulon]

It's on this one, I have some number punches, should I donate them to Laser ?.😃