Yorkman

thanks Simon as puffin models didn't have a shipset of motors, and I can't find them anywhere else-am going to go for plan 'b'- as I don't own a wattmeter, but I do own some kitchen scales, the plan is to chuck a couple of nicad packs back in, measure the  static thrust , then put the lipos back in and find an equivalent throttle setting-than, as you suggest, leave the rest for 'take off power' or 'war emergency power'! will just have to organise a 'gate' for the throttle lever........and wait for some test flying weather.... certainly still intend to change to the 3s motors when available tho. btw-did donwsize from 9x5s to 8x4 props but still waaaaaaay too hot

Warminster? Is that Lordshill? I'm going to need something to entertain my kids as boating is definitely out... Perhaps you can get a few more tickets and we can all go see Dolly?                                                                                                                                 

ps-anyone going to be at middle wallop this weekend? (i know the forecast is abysmal!)

will certainly let you know how I get on.

Timbo-apologies. 'Opposed' somewhat overstating the case-less than enthusiastic, perhaps? John-interesting that you reckon I now have twice the power to previously. Power is not an issue, it was weight loss that was needed, so I don't need super-duper brushless or these brushed ones running at their absolute limit.... I think I will be giving those 3 cell motors a try-has anyone on here any experience of them? Thanks for your thoughts folks. Martin

Hmmmm why are you opposed to those motors wound specifically for 3s lipos? To me seems the obvious answer? throttling back obviously takes place anyway, but static testing is getting motors very hot on approx 70% power and i've put smaller props (8x4) on as well...

shirley that's a P40, not a P51? I'll get my anorak........

Thanks for the responses guys. The model is 6' span, the weight about 5 1/2 lbs (weighed it the other day-have forgotten!) wingloading now 20 oz/sq ft. I don't have any means of measuring the current drawn. I did consider going brushless, but the cost is prohibitive cosidering the use the model gets/will get-the decision to resurrect it was based on the info that brushed would be ok with the lipo pack! Timbo-if what you say-15 flights only before motor burn out-what do you think about these motors http://www.puffinmodels.com/product.php?prod=1072 which appear to answer the problem? Also, if the parallel wiring setup is contributing to the problem, rewirng to four separate motor/esc is feasible-brushed 30amp esc cheap as chips from giantcod.co.uk ps-think I may have already burnt out 1 motor!

don't you hate it when newbies come along and win the prizes?

Hi all As a very part time model flyer, I decided to dig out my Avro York (scratchbuilt by my dad-true scale) after a couple of years in mothballs, and get it in the air again. Although flown successfully over a couple of years (you may have seen it in the air at Lordshill a couple of years back) it was always a mighty struggle to defeat gravity-a wingloading around 26oz/sq ft and speed 400s on 7 cells-I decided that weight loss was the order of the day and junking the two 1900 nicad packs for a single 4100mah lipo pack did that nicely! My concern had been the motors-7.2v-coping with the voltage of a 3 cell lipo. I was told that they should be fine, but testing (and an abortive test flight) seems to be indicating otherwise... Basically, at full power static runs I'm getting fantastic thrust but the motors are worryingly hot (as are the speed controllers)-the battery seems to be barely breathing heavily... The setup is-the 4 speed 400 7.2v motors are wired in two parallel pairs,  driving 9x6 props through 2.25-1 reduction gearboxes,two 30amp speed controllers,4100mah lipo pack. What expert opinions can I get on this? I assume there are some experts on here?;-) Thanks in advance Martin