Laser Engines - Technical questions

Guys,

I have had it hotter than hell using a paint stripper gun and I've tried all the other stuff and more.

My DIY hub puller just bends after cranking the thrust bolt to the max. I will have to find a way to reinforce it.

A.

Andy, I am no engine man but have you tried immersing the engine for several hours in glow fuel or any other solvent to soften the baked goo?

It does sound like you need more of a man of a puller, that and some heat with puller on. Ron's tap method also works.

Never needed to strip a Laser but have done many others with the same problem. Often, a heat gun is not enough and they require rather more which means a blow torch. I do not possess a puller but a good smack on the prop nut(s) with a hammer usually does the trick as long as the prop driver is hot enough. Constant pressure from a puller is unlikely to be effective.

You either need a beefier puller or a press. I use a press here as its the only chance i have on some of the older engines where the thing has been together for 20 years or whatever. Some of them take an astonishing amount of pressure to get them out. Heating it up wont really do much to help in this instance.

Finally success, I ventured out to get the parts I needed to beef-up my puller and with the front housing back in the puller, with no heat this time, I cranked up the thrust bolt with as much force as I could muster and it finally came off with an explosive crack and the taper collet shot off like a bullet. I have measured up all the bearings and ordered a set of 3. Now to clean up all the gunk which has accumulated and been cooked on. The liner still looks in perfect condition which was a concern until it was apart.

Andy.

Well done. Cant beat a bit of beef.

If using the puller often as not once you have a bit of tension wound on you can shift the offending part by giving the puller a sharp tap with a hammer.

As for cleaning I always use boiling water and aerial biological washing powder, cleans them up a treat.

Any light surface corrosion or tarnishing I get off with scotchbrite.

Jon,

I have now stripped the entire engine down but in the process of re-bedding in the valves I have discovered that both springs had broken about, 1 1/2 turns off the end of each, can I buy replacements direct from you, and it wouldn't hurt to have some split collets, I haven't lost one yet but there's always the risk when refitting them by hand.

Thanks,

Andy.

Difficult to do at first but when messing around with those fiddly collets stick the whole thing (including your hands) inside a clear plastic bag and do the work in there!

Andy, give me a call when you can and we can sort it out. Springs are readily available as are collets should you loose one.

Ron,

I tried that trick when I first de-coked a Laser but it just steamed up and I couldn't see anything.

Jon,

I'll call you tomorrow to arrange the parts I need.

Andy.

Just a thought, I want to buy A LASER 70, but if I mount it upright, isnt the carb fuel inlet to high for the fuel level ?

Conversely will it flood if I invert the engine, Its going in a Panic

??

Maurice

Edited By Martin Harris on 19/12/2020 17:45:33

A common conundrum, easy answer side mount it.

Tony

Edited By Martin Harris on 19/12/2020 17:46:04

Jon has often said that there's little or no problem lifting fuel - flooding from too high a tank is the real problem.

Edited By Martin Harris on 19/12/2020 17:46:30

I agree mostly, I think there's too much worry about tank position. It stems from old freeflight designs with much less sophisticated engines. On another forum there was some hysteria about getting it spot-on only to read on that it was for an aerobatic design where the fuel is all over the place during manoeuvres and especially when prop hanging. If on the ground, the fuel is leaking due to the tank being high just close the throttle until needed. If it's low an extended prime may be necessary.

Edited By Martin Harris on 19/12/2020 17:46:52

I have what seems a silly question that may have been asked previously, can the carburettor and silencer be swapped around. Many Thanks

Vincent,

Definitely not without making a lot of modifications, the intake and the exhaust are fixed in the design, although I notice on the Vee twin engines the cylinders are mirror versions of each other.

Andy.

Jon will probably chip in soon, but it maybe possible if you swap the cams over and adjust the valve timing accordingly.