WenMac MK.III Help Please

NEW222 Mon Apr 20, 2015 4:17 pm

Hi there. I had acquired this little old .049 engine and have had a couple of problems. Firstly, the built in spring starter is broken. The spring is broken off of the center near the shaft, so it does not work. Secondly, I am familiar with the crock pot method of cleaning and would like to do so, except I cannot remove the plastic piece nearest the crankcase. It is really gummed up in the needle area outside and in. Seeing as it does not work anyways, could I use a dremel to remove the rivet heads that appear to hold it on and discard it? As for the rest, it should be a no brainer as to disassembly. I was going to try trading for a Cox engine but thought since broken, it would not be wanted nor worth the shipping so decided to clean and hang it aboard my Baby Ringmaster. Oh, and lastly, what type of glow plug would I need for this? Standard short? Thank you.

[img]

[/img]

[img]

[/img]

[img]

[/img]

gossie Mon Apr 20, 2015 5:05 pm

I've had/have several early Wenmacs and they will flick start okay.......Rotomatic starter is not needed. Mk111 is good model and some in Nos. Power use them and take off the starter to save weight. As said grind off the rivet.

Short hot plug and plenty of nitro will run it okay.......my general mix is 50% methanol, 25% castor, 25% nitro. Good hot mix is 25% methanol, 25% castor, 50% nitro. I always mix my own fuel.
5 X 3, 5 X 4 or thinned 6 X 3 props. Well balanced of course.
If you can't get short plugs use extra copper gaskets that come with plugs and use a hot long reach to shorten it.

Just clean it up with a tooth brush and lacquer thinner, and blow the spray bar out by putting fuel tube onto it with needle out.

NEW222 Mon Apr 20, 2015 6:16 pm

Thank you for the help and advice. It is also good to know that they do flick start ok as well. I will heed the advice and grind off the starter assembly later tonight or tomorrow. Just another little question regarding the backplate. There is a hole in the center of it. Is it for some kind of feed, or just mount the darn thing and ignore it? Thanks again.

chevyiron420 Mon Apr 20, 2015 6:36 pm

New, its your engine so do what you want, but I wouldnt remove the start housing. I would just remove the spring and centre sleeve and re-install the drive plate. That way if you get hold of a cheep pipe bomb you can steel the spring out of it. The hole in the rear plug is for a single fuel tank mounting screw. Dont worry with it.
You can try a OS6 plug with two gaskets, or a 1/4x32 1/2a plug from merlin with 3 gaskets. You may have to experiment some there, but usually fox short plugs have not worked for me.
Phil

rsv1cox Mon Apr 20, 2015 7:03 pm

chevyiron420 wrote:New, its your engine so do what you want, but I wouldnt remove the start housing. I would just remove the spring and centre sleeve and re-install the drive plate. That way if you get hold of a cheep pipe bomb you can steel the spring out of it. The hole in the rear plug is for a single fuel tank mounting screw. Dont worry with it.
You can try a OS6 plug with two gaskets, or a 1/4x32 1/2a plug from merlin with 3 gaskets. You may have to experiment some there, but usually fox short plugs have not worked for me.
Phil

Good advise all around here new222, I have come to really like these Wen Macs, they start easy and run well.

Phil, I have been looking for a proper plug for my Wen Mac .049's, I checked ebay and for a card of 6 the best price I could find is $27.00 with free shipping for the OS6 plug from overseas. Do you know of a domestic source?

chevyiron420 Mon Apr 20, 2015 7:24 pm

I have the best OS plug set-up ever. My son uses OS engines, and buys plugs for them and stores them in my flight box! I have never bought one! Its like I said before though, I rarely run the old style wen macs. There is a little wizard here with one but it is really my wife’s plane. I do bench run them some and the four I have dont all want the same plug. Try the Merlin 1/2a quarter inch plug with extra washers. It will probably work for ya and if not it will work great in conversion heads. Buy the hot ones. You can order them direct on line.
The problem with most short plugs, in my opinion, they are designed for .15's and the wire is to thick for 1/2a engines. If you notice, if you find one of the little tiny original plugs that still works, all your wen macs will run great on it.
Phil

NEW222 Mon Apr 20, 2015 7:59 pm

Okey dokey. Thanks all. So, it appears that I will now do just a little exterior cleaning and retain the starter in case I should happen to come across the parts to rebuild mine one day. I will take a peek around, but now after all of this talking, I think it may have come with a plug, as I had seen an odd looking little ba%$&rd kicking around. Thanks again.

gossie Mon Apr 20, 2015 9:32 pm

FWIW I was just taking a look at some of my stuff and I found, but knew I had, a MK111 just like yours but without the spring in the Rotomatic.
It still has the rear housing on it, and you may have noticed how heavy the prop. driver is.......it's actually like a flywheel.........maybe it's meant to be to help the starting?????

This one is also missing the needle........I have others so one of those can be used if need be.

It has a metal tank on it using a screw to go into the threaded hole in the backplate on the rear.

Put a 5X 3 on it, gave it an oil up and and a few flicks over and it feels really nice.......to be truthful I can't remember if I have run this one or not?????? Maybe yes, maybe no??????

NEW222 Mon Apr 20, 2015 9:43 pm

Well, back from the dungeon again. I removed the needle, was able to see through the spraybar (?) and it appeared clean. So I then hooked up a small piece of fuel tubing to the fuel nipple and blew through it. Nothing, no air at all coming through. So as I started to loosen up the needle, I kept blowing through it. Then like magic, it was passing through the venturi(?). So, all in all, it appears to be in running condition. So I took a look and found the weird little plug I was thinking about. It is definitely different from the others in style and design. It has what appears to be the standard hex shape for tightening, except with a 'cut' in the middle making it appear to be 2 nuts in appearance. Anyways, I will just have to look for a copper gasket then attempt to fire this thing up hopefully this weekend. Thanks all again for the help.

**Cribbs74** Mon Apr 20, 2015 10:22 pm

New,

I have a butt load of Babe Bee parts. I can make you a good useable one and send it to you free of charge.

You would probably be more happy.

gossie Tue Apr 21, 2015 4:11 am

Cribbs74 wrote:New,

I have a butt load of Babe Bee parts. I can make you a good useable one and send it to you free of charge.

You would probably be more happy.

Very nice offer Cribbs. Too good to refuse may I say.

Cox reed is probably a better option than the Wenmac, and why I have a lot of Cox reed and Tee Dee engines that are great, but if NEW is like me he enjoys messing with old mechanical things and getting them going.

Oldenginerod Tue Apr 21, 2015 5:39 am

NEW222 wrote:So I took a look and found the weird little plug I was thinking about. It is definitely different from the others in style and design. It has what appears to be the standard hex shape for tightening, except with a 'cut' in the middle making it appear to be 2 nuts in appearance.

Here's a couple of pictures of an original Wen Mac plug. (not good pics I'm afraid). Should be enough to identify if yours is an original. There were a few with that "double hex" design.

Rod.

NEW222 Tue Apr 21, 2015 1:22 pm

Great. Thanks for the pictures. That is the one I have. While playing around yesterday before Cribbs' offer, I thought I saw something small and silver in color go flying. It appears to have been my head gasket.

chevyiron420 Tue Apr 21, 2015 6:02 pm

With the talk of removing the starter I thought I would post a couple of pic's of my baby ringmaster with a wen mac mark XII on it. It had a gutted prop drive hub on it until the splines stripped out, then I put a cox hub on it with a cox spinner.
Phil

gossie Tue Apr 21, 2015 6:59 pm

chevyiron420 wrote:With the talk of removing the starter I thought I would post a couple of pic's of my baby ringmaster with a wen mac mark XII on it. It had a gutted prop drive hub on it until the splines stripped out, then I put a cox hub on it with a cox spinner.
Phil

That's interesting. Splines on them are very fine, and as yet all mine are okay, but will keep that clue in mind. Thanks.

Sponsored content

WenMac MK.III Help Please

WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please

Re: WenMac MK.III Help Please