Log in
Search
Latest topics
» Indexing COX cylindersby davidll1984 Today at 7:56 am
» Another of C.T. engines cleaned ---- Cox Tee Dee .09 --- Just today (3/26/2024) more Cox parts
by Yabby Today at 7:47 am
» Introducing our Cox .049 TD Engines
by Yabby Today at 6:33 am
» STUKA bomb dimentions needed
by latole Today at 5:44 am
» 1/2a Skyray plans?
by 944_Jim Yesterday at 10:14 pm
» Postage stamp backplates
by JPvelo Yesterday at 8:52 pm
» my attempt at making an exhaust throttle for Cox .049
by roddie Yesterday at 8:20 pm
» Cosmic Winds, - Big Guy, Little Guys, Silver Guy and Wounded Guy.
by rsv1cox Yesterday at 5:18 pm
» My friend Ramón, his Cox .09 & Cox .010
by MauricioB Yesterday at 12:31 pm
» Parts Cox TD-4
by rsv1cox Yesterday at 8:40 am
» On ebay a very special Cox engine
by davidll1984 Yesterday at 6:32 am
» Introducing the new - "QZ" RR-1
by Admin Yesterday at 12:51 am
Understanding the Wen Mac recoil spring starting system
Page 1 of 1
Understanding the Wen Mac recoil spring starting system
Perhaps more for the newbys than the seasoned old pros here.
I recently added six more various Wen Mac engines to my already extensive stash and decided to dismantle three of them completely. All were locked up with old castor. Popped all three in the toaster oven at about 250 degrees for 10 minutes. Removed using a leather glove, added a wooden prop and all three loosened like magic.
One would wind against the spring and recoil but would not operate in a proper counter clockwise direction. Using a couple of screwdrivers on opposite sides I pried off the forward drive plate exposing the cam and the spring. Max gunk, cleaned that up and reassembled. Still no counter clockwise function.
Looking closer at the forward drive plate I noticed that it is actually a sandwich affair with a paul of some sort between the two outer pieces. Hmmm, I thought it was a plunge and release mechanism, but it's actually a slip ring affair.
I heated the plate, soaked with Rem oil and finally worked it loose with a whole lot of gunk being expelled from inside the plate.
Put everything back together, added a prop and it works like new.
I recently added six more various Wen Mac engines to my already extensive stash and decided to dismantle three of them completely. All were locked up with old castor. Popped all three in the toaster oven at about 250 degrees for 10 minutes. Removed using a leather glove, added a wooden prop and all three loosened like magic.
One would wind against the spring and recoil but would not operate in a proper counter clockwise direction. Using a couple of screwdrivers on opposite sides I pried off the forward drive plate exposing the cam and the spring. Max gunk, cleaned that up and reassembled. Still no counter clockwise function.
Looking closer at the forward drive plate I noticed that it is actually a sandwich affair with a paul of some sort between the two outer pieces. Hmmm, I thought it was a plunge and release mechanism, but it's actually a slip ring affair.
I heated the plate, soaked with Rem oil and finally worked it loose with a whole lot of gunk being expelled from inside the plate.
Put everything back together, added a prop and it works like new.
rsv1cox- Top Poster
-
Posts : 10429
Join date : 2014-08-18
Location : West Virginia
Re: Understanding the Wen Mac recoil spring starting system
You need to be real careful when removing these that you don't dent the inner plate on the clutch mechanism, or it will lock and refuse to free-wheel, even with a small dent. Also when assembling, be sure to line the pawls up with the cam to which the spring attaches.
Oldenginerod- Top Poster
- Posts : 3962
Join date : 2012-06-15
Age : 61
Location : Drouin, Victoria
Re: Understanding the Wen Mac recoil spring starting system
I can see how that could happen Rod. I wasn't particularly careful when removing the outer plate thinking it solid and got lucky. I would like to make a couple of hardwood wedges to use in the future.
I found that if I were careful I could feel the pawls align with the cam before using the prop and drive nut to seat the assembly.
I hope that you received my PM regarding your Mom.
I found that if I were careful I could feel the pawls align with the cam before using the prop and drive nut to seat the assembly.
I hope that you received my PM regarding your Mom.
rsv1cox- Top Poster
-
Posts : 10429
Join date : 2014-08-18
Location : West Virginia
Re: Understanding the Wen Mac recoil spring starting system
I have two or three of those models with the V on the side and they run pretty good, about like a Babe Bee single port. I dont use them for much, but There neet. My wife has one on a little wizzard.
Phil
Phil
chevyiron420- Gold Member
- Posts : 251
Join date : 2015-01-28
Age : 66
Location : Barney Georgia
Re: Understanding the Wen Mac recoil spring starting system
Thanks for showing us. I've never known what was in there.
Rusty
Rusty
_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
RknRusty- Rest In Peace
- Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA
Re: Understanding the Wen Mac recoil spring starting system
Thank you. I had acquired one of these, but had never known what the big black discs in front were or what they were for. I will now go and try mine out to see how it works. Should I just wind the prop clockwise from the front a turn and see if it goes? Thank you.
NEW222- Top Poster
- Posts : 3885
Join date : 2011-08-13
Age : 45
Location : oakbank, mb
Re: Understanding the Wen Mac recoil spring starting system
It takes a couple of turns clockwise to wind the spring, it will stop when fully wound. Watch out when you release, the prop has a nasty way of finding a finger.
IMO Wen Mac's system beats the Cox afterthought spring. There is no engagement to worry about, just wind and let go.
IMO Wen Mac's system beats the Cox afterthought spring. There is no engagement to worry about, just wind and let go.
rsv1cox- Top Poster
-
Posts : 10429
Join date : 2014-08-18
Location : West Virginia
Re: Understanding the Wen Mac recoil spring starting system
Well Cox did introduce a similar wind back starter, but they were taken to court over it and forced to remove it from sale, I believe. The wind-back version has become rather valuable from a collectors perspective.
The earlier Wen Mac starters with the rivited spring were fairly reliable, but the later Testors ones changed to a hook end on the spring and they were very fragile. They are truely "no-drag" starters because the pawls disengage with centrifugal force so there is virtually no friction at all. But they are probably a little heavy, with quite a bit of spinning weight in the clutch.
Rod.
The earlier Wen Mac starters with the rivited spring were fairly reliable, but the later Testors ones changed to a hook end on the spring and they were very fragile. They are truely "no-drag" starters because the pawls disengage with centrifugal force so there is virtually no friction at all. But they are probably a little heavy, with quite a bit of spinning weight in the clutch.
Rod.
Oldenginerod- Top Poster
- Posts : 3962
Join date : 2012-06-15
Age : 61
Location : Drouin, Victoria
Oldenginerod- Top Poster
- Posts : 3962
Join date : 2012-06-15
Age : 61
Location : Drouin, Victoria
Re: Understanding the Wen Mac recoil spring starting system
Thanks for the help and advice. I carefully used a screwdriver and separated the two halves only to find out that the spring is broken at the rivet near the shaft side. So no more worrying about how it works for me, as it doesn't.
NEW222- Top Poster
- Posts : 3885
Join date : 2011-08-13
Age : 45
Location : oakbank, mb
Re: Understanding the Wen Mac recoil spring starting system
Oldenginerod wrote:Well Cox did introduce a similar wind back starter, but they were taken to court over it and forced to remove it from sale, I believe. The wind-back version has become rather valuable from a collectors perspective.
The earlier Wen Mac starters with the rivited spring were fairly reliable, but the later Testors ones changed to a hook end on the spring and they were very fragile. They are truely "no-drag" starters because the pawls disengage with centrifugal force so there is virtually no friction at all. But they are probably a little heavy, with quite a bit of spinning weight in the clutch.
Rod.
Rod,
I don't think it ever went to court, they were likely sent a cease and desist from Testor's attorneys. Cox stopped production sometime in '72 and scrapped the remainder of starters.
Re: Understanding the Wen Mac recoil spring starting system
Ok, now since my spring is broken on my starter, is there any way to remove the assembly from the engine as it is dead weight, or should I leave the starter assembly on anyways. Also, could someone please tell me as to what size prop is best suited for a MK III .049 engine, as well as what to drill the prop hole to. Thank you.
NEW222- Top Poster
- Posts : 3885
Join date : 2011-08-13
Age : 45
Location : oakbank, mb
Re: Understanding the Wen Mac recoil spring starting system
My experience with the early types of wen macs is limited, but here is what I have found. The performance of these engines varies from engine to engine. I would experiment with 5x3-5x4, then 5 1/2x3-5 1/2x4 props, and drill to .161-.166.
If the spring is broke you can rob one from a pipe bomb. Even though the starter housing is smaller on the bomb, they work for me. If you decide to run it as is it is a good idea to remove the prop drive and remove the sleeve under there. You dont want it spinning around on the nose of the crankcase. Also I have found these engines to be sensitive to glow plugs. I have had them go from barley running to good performance and everywhere in between just by plug changes.
Phil
If the spring is broke you can rob one from a pipe bomb. Even though the starter housing is smaller on the bomb, they work for me. If you decide to run it as is it is a good idea to remove the prop drive and remove the sleeve under there. You dont want it spinning around on the nose of the crankcase. Also I have found these engines to be sensitive to glow plugs. I have had them go from barley running to good performance and everywhere in between just by plug changes.
Phil
chevyiron420- Gold Member
- Posts : 251
Join date : 2015-01-28
Age : 66
Location : Barney Georgia
Re: Understanding the Wen Mac recoil spring starting system
I just now ran across this discussion. I have both a Wen-Mac and a Testers/McCoy .049. I recently saw a heavily use Wen-Mac in eBay and purchased it for the recoil winder. After careful examination of my two engines I guessed the Wen-Mac winder would fit the Testers/McCoy. After removing and cleaning all the gunk out of the winder I installed the Wen-Mac winder on the McCoy. Perfect fit! Thanks guys for the disassembly information. My McCoy lives to fly another day
Nhschreiner- New Member
- Posts : 3
Join date : 2022-07-05
Age : 68
Location : Manchester, NH
Re: Understanding the Wen Mac recoil spring starting system
Nhschreiner wrote:I just now ran across this discussion. I have both a Wen-Mac and a Testers/McCoy .049. I recently saw a heavily use Wen-Mac in eBay and purchased it for the recoil winder. After careful examination of my two engines I guessed the Wen-Mac winder would fit the Testers/McCoy. After removing and cleaning all the gunk out of the winder I installed the Wen-Mac winder on the McCoy. Perfect fit! Thanks guys for the disassembly information. My McCoy lives to fly another day
Ah, Manchester NH, the Queen city. I was born and raised in Raymond, some 18 miles to your East. I was in high school when you were born. I spent a lot of time in Manchester.
I'm glad that you gave this thread new life, I contributed (above) but lost sight of it. I did not know that Rod had posted a picture of the Cox version. Saved it to my files. I must say that the Wen Mac/Testors version is the better of the two. Internal coil/watch spring makes a big difference in function, appearance, and ease of cleaning. I always flush mine out with RemOil/compressed air after each run. Cylinder also.
Welcome to the forum.
rsv1cox- Top Poster
-
Posts : 10429
Join date : 2014-08-18
Location : West Virginia
Re: Understanding the Wen Mac recoil spring starting system
rsv1cox wrote:Perhaps more for the newbys than the seasoned old pros here.
I recently added six more various Wen Mac engines to my already extensive stash and decided to dismantle three of them completely. All were locked up with old castor. Popped all three in the toaster oven at about 250 degrees for 10 minutes. Removed using a leather glove, added a wooden prop and all three loosened like magic.
One would wind against the spring and recoil but would not operate in a proper counter clockwise direction. Using a couple of screwdrivers on opposite sides I pried off the forward drive plate exposing the cam and the spring. Max gunk, cleaned that up and reassembled. Still no counter clockwise function.
Looking closer at the forward drive plate I noticed that it is actually a sandwich affair with a paul of some sort between the two outer pieces. Hmmm, I thought it was a plunge and release mechanism, but it's actually a slip ring affair.
I heated the plate, soaked with Rem oil and finally worked it loose with a whole lot of gunk being expelled from inside the plate.
Put everything back together, added a prop and it works like new.
Hello rsv1cox
I have a wen mac that had the starter spring broken. I took the unit out and pressed a cox .049 prop drive washer and it has worked for me. I did this a while back I think I used a plastic prop to press the washer in on the crank using a flat washer and a nut. here are a couple of pics.
juan
F4D Phantom II- Gold Member
- Posts : 159
Join date : 2019-04-08
Re: Understanding the Wen Mac recoil spring starting system
Hi Juan, Good idea and a great fix. Saved an engine. I'm going to start running the Wens and Testors again.
BTW, I no longer use a toaster oven, a heat gun works so much better. April 16th, 2015, nine years how time flys.
BTW, I no longer use a toaster oven, a heat gun works so much better. April 16th, 2015, nine years how time flys.
rsv1cox- Top Poster
-
Posts : 10429
Join date : 2014-08-18
Location : West Virginia
Re: Understanding the Wen Mac recoil spring starting system
What a great and neat idea. I too have one with a broken spring starter and just left it as I did not know of any other options. Looks like I will have to add a drive washer to an order when I have to make another order from Coxinternational, but unfortunately that will not be for a while. But on the bright side, it still does run with the hub there.
NEW222- Top Poster
- Posts : 3885
Join date : 2011-08-13
Age : 45
Location : oakbank, mb
Similar topics
» Part needed for McCoy No. 2 .049 engine
» Help...I'm not understanding this auction.
» cox recoil cord
» Cleaning engines crock pot style
» Baja Bug / Dune Buggy Recoil Starter
» Help...I'm not understanding this auction.
» cox recoil cord
» Cleaning engines crock pot style
» Baja Bug / Dune Buggy Recoil Starter
Page 1 of 1
Permissions in this forum:
You cannot reply to topics in this forum