Ashley Hunt

These replies are all really helpful. It seems that to err on the side of caution by balancing it with the nose a few degrees down will make a good starting point. Thanks very much.

Thanks to lockdown I’ve built a Puppeteer that’s been waiting for about 35 years to be completed. In previous discussions on this site about the balancing of a Puppeteer nearly everyone said that the balance point as shown on the plans was not correct and that that it should be balanced with the nose down. So my question now that I’ve come to that point is how much nose down, a little or a lot ? I suppose it would be really helpful if someone could tell me how much further forward from the marked balance point on the wings I should go. Thanks.

Hi Martin. That's exactly the information I was after, thanks very much.

I’m about to try running my old Laser .61 but no matter how hard I look I can’t find the running instructions that originally came with the engine. Can anyone help me with the settings for the high and low speed needle valves and any other advice on starting and running the engine. I’ve been able to get advice from Laser for the valve clearances and type of fuel but that was all. The engine dates from probably the late eighties.

Thanks for that latest reply Mike. Several people have now suggested cutting into the existing firewall to avoid extending the nose of the model which is something I’ll now do. Can you remember what size tank you used with the Laser 70 engine, did you use the one supplied with the kit or a larger one ? When you say blank off the front of the cowl presumably you then had to cut a section out of the cowl to get the air over the engine.

Thanks for all the replies, the suggestions are all really helpful. I’ll keep going with the Laser 61, mount it on the existing firewall and see how it balances out. A rough measurement suggests that I may have to push the nose out by somewhere between 25 and 35 mm. I’ll also make sure to balance it nose down. I’ve kept the kit and engine for so long now that it would seem wrong to not put them together !

I’m in the process of building a Puppeteer from a kit that I bought back in the 80’s. I’ve been reading some of the past threads on these models and the impression I get is that to get the balance correct an amount of lead has to be added to the firewall. I’d like to fit an equally old Laser 60 four stroke but it’s quite a lump of an engine and to be able to use it I’d have extend the cowl forward by quite a distance. Although this would probably negate the use of any additional lead. I’m sure this is a common problem so does anyone out there have any thoughts ?

Peter, that’s sound and sensible advice, thanks. I have in fact bought a Hobbyzone Carbon Cub S+ which is proving to be brilliant for the purpose. I would highly recommend it to anyone else in the same position. You can switch out the aids as you regain confidence and in the experienced mode it will keep most radio controllers on their toes ! Thanks again for the thought though.

That’ Brilliant. Thanks.

I’ve recently dug my ancient Mick Reeves Spitfire out of the loft and refurbished it. I seem to remember that on the ground it pulled to one side on take off but I can’t remember whether it was left or right. I remedied it by mixing in some rudder with the throttle which I could switch in just for take off. Prop rotation is anti clockwise. Can anyone help wit direction of pull ?

I have run the engine loads in the past so it’s not a reverse rotation crank but that was an inspired suggestion. Thanks.

Thanks for the suggestions. I’m fairly certain that the plumbing is correct so it can only be that the cylinder liner has rotated slightly. Thanks again.

I’m hoping that someone out there can help me with a problem that I have with an old Irvine 61 engine. It hadn’t been run for about 15 years so I stripped it all down, cleaned and inspected everything. All seemed fine so having put it all back together again I tried giving it a run. What I’m finding is that when I try and draw fuel through from the tank by putting my finger over the carburettor air inlet and flicking the prop it appears to pressurise the tank and pushes fuel back up the pipe to silencer. Very frustrating and messy. Any ideas anyone ?