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New Laser engines. What do you want?

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Jon Harper - Laser Engines27/11/2017 13:51:30
3178 forum posts
130 photos
Posted by David P Williams on 27/11/2017 11:42:37:
I'll leave my TopFlite 1/5 85" P51 in the box for a while longer then Jon

It might be quite a while but again, thats the ideal candidate and the sort of model i have in mind.

As i think i have said before i design engines based upon the models i have and the engine i want for them. I work on the basis that if i want it for XXX type of model then someone else must want one as well.

In the case of my DB Hurricane and spitfire im thinking of a 50cc 4 stroke that fits in the cowl so that is what i designed. The engine is compact for its capacity but purposefully shaped to help it fit WWII inline style cowls.

I also have a 1/4 scale La7 fighter of 97''. For that i drew up an 88cc radial as there were none that size available at the time. Since then saito have their 84 and 90, but mine is quite different and i am confident it will be better in many ways. Assuming i can get the thing built before we all start using warp drives.

Edited By Jon Harper - Laser Engines on 27/11/2017 13:52:23

Ron Gray27/11/2017 15:52:46
345 forum posts
111 photos

Cor, you bringing out a warp drive Jon? When? How much? How big? Can I put my name down for one please?

trebor05/12/2017 18:35:04
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1298 forum posts
155 photos

Any chance of engine sizes for this pair that came into my mitts. The grubby one is supposed to be low air miles dont know the other lived most of its life in a box. They seem the same size, the only difference I can see are the barrel fins. One has rounded edges the other left more flat, both plugs are mounted in the top laugh so hopefully Im ok for spares. Both are gummed up solid crying

img_2674.jpg

Jon Harper - Laser Engines05/12/2017 18:48:37
3178 forum posts
130 photos

i think the one on the left was part of an archeological dig!

Anyway I think they are both 70's from the 1992-1994 period but the less dirty one could be a very late 62. Is there anything stamped on the crankcases?

trebor05/12/2017 18:57:30
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1298 forum posts
155 photos

They are just stamped on the edge of mounting flange, dirty one has (T F L), clean one has (K T F). I had a look on the Laser website and I couldn't see any gasket sets I think I'm gonna need some laugh

Don Fry05/12/2017 18:59:14
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1876 forum posts
25 photos

I bow to the master, but there was me thinking they look modernish. That's 25 years modernish.

If a 70, do you want to sell one. Don't need two comrade.

trebor05/12/2017 19:04:52
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1298 forum posts
155 photos

The dirty ones out of an old biplane and I thought with a little work it would be a nice winter hack ( wishful thinking ) and the other might go into my very old Astrohog to replace a gutless Os 61 fs.

Jon Harper - Laser Engines05/12/2017 20:05:39
3178 forum posts
130 photos

ah ok well KT will be the initials of the guy who bought them and the L/K is the year of manufacture.

It went by car reg's in those days so L is 1993 and K 1992. That stands to reason as the older engine also has the older type exhaust and liner. They probably both have chrome liners in them but beyond that I can still service them no problem. They don't have any gaskets in them, just O rings for the carb and exhaust stub. Other than bearings and piston rings there is not really much that can go wrong

trebor06/12/2017 06:36:05
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1298 forum posts
155 photos

yes I'll have a look inside both to see if they are jammed or gummed up. Nice to know parts are still available in the UK laugh

bert baker06/12/2017 08:41:02
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895 forum posts
192 photos

Might be worth submerging and allow to soak for a few days in a tub of glow fuel,

Diesel is a good one to free of gummed up engines, you can run into problems with the o rings swelling

trebor06/12/2017 08:57:28
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1298 forum posts
155 photos

I should have taken a picture of the fuel tank, 1/2 " of black gunk inside. Rotting fuel bung rubber with a touch of corroded brass weight and tubes. Good job the wife was out when I cleaned them in the kitchen, the smell lingered, she thought I'd been house diy painting blush

Ikura06/12/2017 09:18:40
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83 forum posts

Ultrasonic cleaners work like magic on old gummed up stuff. They are as cheap as chips these days and bring metal objects up like new.

You might have to give it a few changes of fluid but it's well worth the effort. I have a couple of Brown Juniors and both came up as good as I could ever have wished for. Also an OS 26 four stroke that was a complete gunked up mess cleaned up like new.

bert baker06/12/2017 10:50:28
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895 forum posts
192 photos

How many hours do they need to be in the ultrasonic cleaner, I tried all sorts of cleaning liquids, but gave up

Martin McIntosh06/12/2017 12:19:15
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2138 forum posts
895 photos

I simply use bit of hard surface cleaner (Tescos or Flash) in a pan of boiling water. Simmer for 10 mins before serving.

Martin Harris06/12/2017 13:02:06
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7193 forum posts
178 photos
Posted by Jon Harper - Laser Engines on 05/12/2017 20:05:39:

ah ok well KT will be the initials of the guy who bought them and the L/K is the year of manufacture.

It went by car reg's in those days so L is 1993 and K 1992. That stands to reason as the older engine also has the older type exhaust and liner. They probably both have chrome liners in them but beyond that I can still service them no problem. They don't have any gaskets in them, just O rings for the carb and exhaust stub. Other than bearings and piston rings there is not really much that can go wrong

Jon - I'm having a little difficulty following the labelling logic - does the date code come before or after the buyer's initials - or was it at the whim of the builder?

My rather vintage 62 (BA/imperial hex sockets) has the letters KRB followed by 62 so logically it must be a prefix i.e. K=1992/3 as I believe the 62 wasn't offered until 1989 whereas you've identified Trebor's dirty engine (TFL) by the suffix L

Which engines were stamped with their capacities? I know the latest ones are but I don't recall seeing many older ones with sizes stamped on them.

laser 62.jpg

P.S. It wasn't me that drilled the extra mounting holes but they have come in useful!

Martin Harris06/12/2017 14:07:56
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7193 forum posts
178 photos

P.P.S. If the K suffix denotes that Trevor's clean engine is the same age as mine and is a 62, it has a rather different cylinder base and crankcase which bulges around (at least) one of the cylinder bolts plus the relocated plug position and later stub fixings. Was K (1992) when the changeover occurred? Also, did the code follow the DVLC September changeover?

Edited By Martin Harris on 06/12/2017 14:13:38

Jon Harper - Laser Engines06/12/2017 14:57:50
3178 forum posts
130 photos

I think the car reg system came in with the current range in 92. Before that it was pretty much on a whim.

the very last 90's and 62's were produced in parallel with the 70 and 100 for a short time and they were stamped with the size so we didnt muddle them up. Once they were dropped sizes were not marked until i started doing it about 2 years ago.

Also, in about 1996 or 7 the date stamp changed from cars to a single number. 8 on its own would be 1998 for example. Then, from 2000 they were stamped 00, 01, 02 etc. Some are stamped M then the year as this signifies metric crank thread as metric and imperial were produced in parallel for a little while as well. Current engines are stamped J (my initial) and then the year. 

All that said there are a few that defy analysis so the following is a general guide to age.

Forward facing plug, super tigre carb, square rocker cover, ba screws 1983-92

Vertical plug but otherwise as above 1992-95

As 92-95 but purple or black irvine carb 1995-1999

Rounded fins/head, oval rocker cover with 2 screws, metric bolts, purple or black irvine carb 1999-2006

As above but with black Laser carb (see website for photos) 2006-12

As above but with metric clip screws 2012-present.

 

This ignores internal changes but gives you an idea.

Edited By Jon Harper - Laser Engines on 06/12/2017 14:59:00

Martin Harris06/12/2017 15:31:41
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7193 forum posts
178 photos

Thanks Jon - perhaps this info should be made into a sticky...might save you some time!

Looks like mine's a '92 model 62 from during the 70 introduction period then.

Jon Harper - Laser Engines06/12/2017 15:46:28
3178 forum posts
130 photos

it looks like one of the later 62's thats for sure.

trebor07/12/2017 12:35:25
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1298 forum posts
155 photos

Well there is no way I dare try running mine if I free them off without a strip down, I've had the dirty one soaking overnight in brake fluid. The head and back plates off and now soaking in white spirit, the exhaust pipe has gone back in brake fluid which is eating the crud off. it's slow going but it won't turn alloy black like caustic cleaners would.

Edited By trebor on 07/12/2017 12:37:19

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