1959 patchwork 18 hp

[marcysibyll]

The power head is from a mid 70's 20 hp Johnson. When the magneto plate hold down screws are tightened, there is little to no advance using the tiller. When screws are left loose, the throttle acts normally. What's up with that. <br />By looking at the parts breeakdown at the Evinrude site, there is nothing missing , or extra between the ring and the magneto plate.<br />What the heck am I doing wrong. I'm so frustrated with it, I'm looking for motors with bad gear box/lower unit or bad power heads.<br /> <br /><br />edited for speelling

 

[Joe Reeves]

Re: 1959 patchwork 18 hp

We've been down this road so I won't repeat myself. However the thought occurred to me that perhaps you aren't using the proper factory retaining screws? I'm wondering if they're too long and are causing binding when inserted to their limits.

 

[marcysibyll]

Re: 1959 patchwork 18 hp

Thought of that a while go- ordered factory screws and no difference.

 

[lark2004]

Re: 1959 patchwork 18 hp

My guess would be that the clamping ring or the alloy ring under it, aren't from the same motor. <br /><br />This could result in the two parts haveing a different clearance (I hope I explained that properly). <br /><br />I know what your going through with doing the jigsaw engine. My 40hp Bigtwin has parts borrowed from 3 models, almost 10 years apart between the oldest parts and the newest.<br /><br />Good luck with it!

 

[R.Johnson]

Re: 1959 patchwork 18 hp

The ring under the brass hold down ring has to be installed, flat side up.

 

[Paul Moir]

Re: 1959 patchwork 18 hp

I'm with R.Johnson/Joe Reeves, make sure you've go *** assembled correctly.<br />You know those warnings that come with the aftermarket coils that say to file down the hold down screws if they're too long due to the coil laminations being thinner than the stock ones? It's never been a problem for me (and I've never really noticed a difference in thickness) but perhaps that's the case here? Try loosening the phillips screws one at a time and try to see if one is the culprit. Alternatively, you can tighten them until you get a bit of resistance, turn the armature plate, and disassemble to see where it's binding from scrapes.

 

[marcysibyll]

Re: 1959 patchwork 18 hp

Will try everything mentioned, but instead of filing down the new $3.85 each screws, I'll try flat washers. <br /><br />I will report back with results when my patience returns and blood pressure drops.

 

[Joe Reeves]

Re: 1959 patchwork 18 hp

Perhaps the brass ring has been tapped a little too hard? See the following.<br /><br />(Magneto Armature Plate)<br />(J. Reeves)<br /> <br />If the armature plate has a a loose fitting, wobbling motion (the plate that the points, coils etc are attached to), it is usually caused by a slightly worn support ring. This allows the point setting to change erratically as the armature plate turns.<br /> <br />The cure is to remove the armature plate so that the support which is attached to the powerhead with 4 screws is visible. Then, with a screwdriver and hammer, or some tool of your choosing, and looking straight down at the support ring, make an indentation at what would be called the 12, 3, 6, and 9 O'clock positions. Install the armature plate and check for a smooth turning wobble free movement.<br /><br />You may need to do that procedure a few times to obtain the proper fit (not too tight, not too loose), but it's worth the effort.

 

[marcysibyll]

Re: 1959 patchwork 18 hp

Blood pressure went down , so into the garage I went.I have put washers under the long Phillips head $3.85 OMC OE screws. With the washers under them, the mag plate moves easy with the tiller throttle. The problem is the 2 short straight blade screws. With these tight, the mag plate is tighter then heck. Very difficult to see on the BRP website. What size and how long should these screws be? and are they Phillips head? With washers under them?<br />Will look tpo see if it's been tapped a little to much next trip out there. <br />Thanks, people.

 

[Paul Moir]

Re: 1959 patchwork 18 hp

No, they should be slot screws. They measure 7/8" long (1/8 fractional length screws are very common on J/E engines) and have a star lock washer on them. thread is #10-24.<br />I wouldn't heasitate to use a 3/4" screw. I always loctite the ignition system screws anyway.

 

[marcysibyll]

Re: 1959 patchwork 18 hp

Thank you Paul . I'll get a couple of new screws and washers and give them a try this weekend. Can allways watch the Packers on the TRV in the garage. And my neighbor wanted to know why I ran cable tv into the garage