1971 Evinrude 4HP Mag plate froze

[Bluestream]

Hello, I picked up a good 71 4 as a project. Has been sitting and has OEM coils which are shot. I have removed the Mag plate and cleaned and lubed the base plate. All look normal, but when I tighten down the 4 screws that hold it in place it all but freezes up. Can move it but very hard. loosen the screws and it move normally. Any ideas?

 

[Crosbyman]

what it turning ok before you worked on it.?

did you install the retaining ring upside down

 

[rat boat]

Hi, I have a 66 3 and a 71 6. I had a similar problem with both the motors. Does yours have a circular or ovular top starter or cylindrical side starter? The trick to fix it? wipe every surface and add marine grease to where ever moves. also, try adding washers under the screws in case they are hitting something.

 

[Crosbyman]

4r71 is a side starter

 

[Bluestream]

what it turning ok before you worked on it.?

did you install the retaining ring upside down

Its Model 4106D
Yes, it was like this when I got it, not sure if the PO put the plate in upside down?? Maybe

 

[racerone]

New screws with the replacement coils ?----If so they might be too long .

 

[Bluestream]

New screws with the replacement coils ?----If so they might be too long .

Do not have new coils yet, everything still 1971 original. Grinding off existing screws should fix things, but seems I should not have to do that. I will look at parts diagram to see if someone may have left something out at some point. Guy who sold it was selling for an older person who had moved to a home, and they tried to get it started, with the coils as they were getting spark

 

[Crosbyman]

mag plate coils etc... pretty much what is on thee older JW CD AD series see book

https://bit.ly/2wqMPTb

not certain….. but I seem to recall the retaining ring must be tapper side up….if your is tappered

 

[racerone]

Flat side is UP.------TAPERED side down.-----What is that 1/2" wide strip of metal on the screw in the picture ?

 

[Crosbyman]

see wasn't certain on the tapper pictures in the red book not to clear thanks

 

[Bluestream]

Flat side is UP.------TAPERED side down.-----What is that 1/2" wide strip of metal on the screw in the picture ?

It looks to be some type of ground strap. At first I though it was a friction device, it looks like a factory item, It looks like the armature retainer plate was removed at one time as there are only 2 screws holding in on. I wonder if it was installed wrong? Are there index marks to install, as there are multiple holes.

I will check the taper on the retailing ring to see if it was put in wrong

 

[racerone]

Agreed on the parts list they seem to call it a ground strap.----Brass ring only fits one way for screw holes to line up.

 

[Bluestream]

So, tapered side was down on mag plate ring (Aluminum part) . Brass retaining ring that is held by three bolts, only two bolts were in, because the third does not match up with hole in block. Its out maybe by 1mm , but just enough it would have to be forced in. I can fix this quick with a file, but I dont think that solves my issue. Now wondering if someone has used the wrong ring on this engine?

I have a 1967 9.5 johnson block lying around, going to see if I can swap rings with than engine looks like same part # 303278

 

[Crosbyman]

I use a sishkabob wood skewer to poke down in the bolt holes and align the retaining plate

If I poke into the wrong location…... I turn the ring to the approximate next location and lock in a bolt the rest can follow

2 long ones for the coil corners and 2 short ones on the plate

 

[Bluestream]

Excellent tip, thanks!

 

[oldboat1]

http://ww2.iboats.com/Crankshaft-Piston/dm/cart_id.046276819--session_id.392981489--view_id.1545428

 

[Bluestream]

So, I have found the problem. At some point someone broke off one of the aluminum boses on the block that accepts the retaining ring screws. It looks like it was clued back on, but was not aligned, so that is why only 2 screws were used to hold the ring. As a result when just 2 screws were tightened, the plate binds up and locks movement.

My only choice now would be to use thread locker and just snug up the remaining two bolts and see if the plate will move freely, or file out one of the holes in the ring and see if the glued boss will hold the third screw and thus minimize the binding. Or, see if I can do a better job with new epoxy, or see if the aluminum boss can be tack welded back on the block.

If these dont work, it's a part out. Too bad as I paid $200 for it as it looked to be mint condition with very low hours.

 

[Crosbyman]

??? how about some pictures so can see what the problem is exactly....

somebody will give you a solution and save your investment :victorious:

 

[Bluestream]

See photo, screwdriver points to broken boss on block

 

[Crosbyman]

Well I am not to up on welding but… maybe you can clean it up ( remove glue) at the base install the base ring then the support ring ... install the bolts (all of them without the mag plate ) and have a welder spot weld the thing in place while it is lined up properly ( make certain the retaining ring free flots under the support ring )

you should then be able to install the mag plate properly using a siskabob stick..

welder comments welcome !!