- This topic has 26 replies, 19 voices, and was last updated 7 years, 6 months ago by
.
-
A ’59 Johnson JW three horse recently came in for a full maintenance tune up but the owner preferred to use cheaper Sierra parts in the magneto instead of OMC/BRP dealer parts. Here’s what I found.
These offshore 18-5181 coils have their laminations stamped together, instead of being riveted together as OMC/BRP ones and some other offshore ones are. I’m not sure what the fit would be like on the coils from other manufacturers but the arc of the laminations is not correct, as seen while holding one in my coil locating ring.
I couldn’t get the hold down screws started without filing some of the potting material from the bottom of the coil. They just don’t line up properly without doing some grinding or filing to the coil. Only enough material was removed to get the screws started as I don’t know how thick the potting material is.
Once the coil was fastened down, there was no room for the spark plug wire or its boot. A definite alignment problem here.
Now its time to get the big guns out and do some serious grinding.
Once the coils were secured, I still had to force the locating ring over them as they were tight. There was also all of this extra long wire to deal with so the wires were shortened and new terminals were installed.
Now it was time to open the 18-5006 tuneup kit to see what surprises it held.
Along with the points and condensers, I was quite surprised as it came with two felts (dry) and the necessary continuity clips and hold down clips! As a bonus, there were two caps of cam grease in the package! This is starting to make my day now as things couldn’t get worse, could they?
Without looking out the window, I could tell it was cloudy out as the new condensers tested out at around .30 uF instead of the required .18 – .22 uF as the OMC/BRP 580321’s do. No problem, lets get the points in and get this motor running!
I use an ohm meter along with Franks tool to set the point gap but I wasn’t getting an ohm reading across the points. Only thru the coil to ground. What? OK, I pulled the points out and polished them with 1500 wet ‘n dry to remove any film on them. That solved the continuity problem but now I can’t set them to where I want them to be. Grrrrr. The slot in the points for the adjusting screw isn’t machined properly to allow for proper adjustment! OK, out with the adjusting screws and set them the old way, pry, pry, pry, tap, tap, tap.
Now for the alignment. The next two pictures show the alignment after bending the fixed point to get their surfaces parallel. I wish I had take a photo of them before I did this.
Before trying to set the gap.
After removing the adjustment screw.
For comparison, here’s a set of used OMC/BRP points showing perfect contact area and alignment which were probably used with a good 580321 condenser judging by the amount of pitting. These points will clean up nicely and can be used again.
The only parts which did fit this motor correctly were from a 439071 carb kit I supplied and surprisingly, the Sierra impeller.
So, where is the quality control in these aftermarket parts production? 🙄
I know one thing for sure though, the next time someone wants me to use certain aftermarket parts, I just might have to say no!
- You must be logged in to reply to this topic.
