12hp sea king trouble!Help

[jasonhowerton]

I have a late 50's 12 hp sea king. It has the gas tank on top. For the last two years I have owned it, I put new plugs and cleaned carb. It runs awesome, for a few times out. Then it gets to where it will only run 1/2 throttle. I am mixing gas 25:1 tcw-3 oil. No e85 crap, just regular unleaded. Its almost as if the plugs have fouled out. Fuel filter is not clogged. Don't know if points could help or not. Please any input is appreciated.

Jason

 

[JB]

Re: 12hp sea king trouble!Help

Ahoy, Jason.

Welcome to iboats.

Really need a model number to verify what it is, Jason. If you can't find that post a photo.

Sounds like you are only making power with one cylinder or your Link 'n' Synch is waaay off. Once we know exactly what you have we can help you get her humming.

 

[jasonhowerton]

Re: 12hp sea king trouble!Help

Here is the #'s

Montgomery Ward
Model No. GG90165
Serial No. 65X633915

Here are photos also. I have painted it.

 

[MRS]

Re: 12hp sea king trouble!Help

Just wondering why mixing 25:1 seems mighty thick to me and would definetly foul a plug. But maybe the old motors mix that heavy most are 50:1 that I know of. Does it smoke alot?

 

[tmcalavy]

Re: 12hp sea king trouble!Help

24:1 and even 16:1 were common factory recommended mixtures prior to 1964. After 64 real bearings instead of bushings were used inside the powerhead, requiring less oil in the mix.

 

[jasonhowerton]

Re: 12hp sea king trouble!Help

It smokes when you first start it up. But my 70hp mercury does the same thing when you first fire it up. I always wondered if that oil ratio is fouling a plug after I use the motor 2 or 3 times. Thats about all I get out out of it before it starts bogging down. It flies across the water when with new plugs. I can get on a plane and haul. After it acts like it fouls a plug i cant even get the front end down. The guy I bought it from is a boat mechenic. I trust in him quite well. Hes who told me to mix gas that thick. I had talked to him about it last year and said it might need points set. What do you guys think. I pulled 1 plug out at a time last night and pulled on rope a little. I know it is at least getting spark to both plugs because both will shock me, I just cant tell if both are getting spark through plug now. I still starts great and idles great. It just has no top end! Any input is appreciated. Thanks!

Jason

 

[steelespike]

Re: 12hp sea king trouble!Help

I'd bet my mothers false teeth your losing one cylinder.Spark is probably
weak.Plug should be a J6J present number is I believe J6C set at .030.
Also adjust your high speed mixture screw to the fastest setting back off toward rich just a tiny bit to be sure its not to lean.And of course the idle mixture screw as well.
But I'll bet you will find the ignition weak on one cylinder.If coils are discolored or cracked they should be replaced.Clean and set the points to .020.
you could have a worn or cracked coil wire touching/shorting under just the right conditions.

 

[jasonhowerton]

Re: 12hp sea king trouble!Help

Ok I will definitely check into that stuff this weekend. I would hope it wouldnt be a coil issue. They were replaced when I bought it. They are only 2 years old. I will still look into them. Thanks.

 

[jasonhowerton]

Re: 12hp sea king trouble!Help

I am going to try and pull the flywheel this weekend and check out the points and look over the coils. But I don't know what I need to torque the flywheel to when I put it back on. If anybody knows this I would appreciate the help. Or if someone knows where i can look some of these type of specs up. I am not a mechanic but I can usually follow directions quite well and use a little common sense to work on things. I am cheap and enjoy fixing things myself as long as I am capable. Thanks again!

 

[jasonhowerton]

Re: 12hp sea king trouble!Help

UPDATE:

I pulled the flywheel and found that the points were not right. The top cylinder was opening to .01. The bottom cylinder was not breaking open at all. I finally got both points set at .020. Put he flywheel back on and it fired right up in the barrel. Have not had a chance to take it on the water yet. Been way to windy here. It seems to be more responsive to the throttle though. So hopefully this was the problem. I am just curious though why it would run great for a couple times out then go to crap. Was the points not being set right causing me to foul plugs???If anyone would like to explain this to me I would appreciate it. I just want to understand better. Thanks!!
Jason:

 

[frwhlr38]

Re: 12hp sea king trouble!Help

Jason, if the points were that far off its no wonder you wernt getting the total amt of spark needed,ive seen this happen with old lawn mowers in the old systems them points are very critical also did you file them points when you reset them to help clean them up ive seen them build up way bad, and not having the right fire coming off them points will deffinatly cause cyl to go down as the motor warms up and points warm up BBILL

 

[steelespike]

Re: 12hp sea king trouble!Help

If the points are set wrong it changes the timing slightly and more importantly the point duration .Another thing that could be going on is if there is no lube on the rubbing block it could wear prematurely causing the points to go out of adjustment.

 

[tmcalavy]

Re: 12hp sea king trouble!Help

Good save, sounds like the PO didn't know how to set the points, or left one set loose. Keep an eye on it, the symptoms you describe fit one bad coil to a tee...good spark for a while, then the bad coil drops out as it warms up and gets under load...end result is running on one cylinder.

 

[jasonhowerton]

Re: 12hp sea king trouble!Help

awesome guys. That makes me feel like I have the problem pointed out. And no i did not file on the points, but i did use a small fine brush just to make sure they were clean. Everything looked like it was replaced when he replaced the coils. As far as lube on the rubbing block what do i use. There was something on it, i did not wipe it off the rubbing block, it almost felt like a light grease. I just made sure i had the taper clean for the flywheel. I will try out on water in the next few days and if I start getting the same issue I will check points again and see if they are off again. I appreciate everything everybody. Thanks.
Jason

 

[jasonhowerton]

Re: 12hp sea king trouble!Help

Update: Motor is running better than it ever has.Gets on plane quisker and hauls. No more rough running when getting up to throttle. Had to back low speed one hole turn in and that was it. Thanks every body. Saved me loads of money not going to a mechanic!
Jason

 

[Shockbolt]

Re: 12hp sea king trouble!Help

So, I have a Seaking 12HP outboard as well and it was having the same issue. I went ahead and created a video on Youtube showing pretty much everthing that was talked about here... Thanks for the info on this forum as it has helped me get my motor in great shape as well. I hope you find this video useful if you are in the same situation!

http://www.youtube.com/watch?v=0SkQLJvsDW8&feature=youtube_gdata