89 Force 50HP turns on and stays on only on high idle start

[Jiggz]

Re: 89 Force 50HP turns on and stays on only on high idle start

Actually that is a very good repair option to use the "Fix-A-Thread" kit. There are some critical points in using this kit:
1. When tapping make sure you chase the original thread and the tap should be perfectly straight. Use cutting oil or even regular oil to lube while tapping. If you cannot tap straight from the top, you can also tap from the inside or bottom.
2. When inserting the insert (use proper size that will flush to the top and bottom of the plug hole), use a spark plug to thread it in but at the same time use hardening threadlock between the insert and the hole (make sure you clean the oil used from the tapping with alcohol, acetone, etc and blow with air to properly dry). Allow threadlock to cure for a day. This will allow you to back off the spark plug without the insert. Remember the insert knurled end goes on top.
3. When swagging the insert, use a wood block for the head to lay on. You'd be better off using multiple medium to light tapping rather than one massive blow that can either crack the head or bow it.

Cleaning the head means cleaning all mating surfaces between the block and head where the gasket goes. As for the water ports, you can try cleaning them but make sure you cover (stuff with clean rags) the cylinders from debris. DO NOT USE GASKET MAKER BETWEEN THE GASKET, HEAD OR BLOCK. NONE IS REQUIRED.

 

[Jiggz]

Re: 89 Force 50HP turns on and stays on only on high idle start

I forgot to respond to your torquing question. This is how I see it. Remember, the torque requirements are in inch-pounds, thus you should use an appropriate torque wrench range (required torque should be within 20-80 percent of range [others require 20-100%**, e.g. if you use a 500 in-lb range torque, your 225 in-lb requirement will be 225/500 = 45%, which is OK since it falls within 20%-80%, but not if you use a 250 in-lb range wherein it becomes 90% of range.). Actually, Harbor Freight has them on sale once in a while for less than $15.00. If you were able to remove the head, you should be able to put in a torque wrench too. The inch-pound torque wrench is not that much bigger than a regular ratchet wrench. But if you used a box wrench, then you will need a torque wrench adapter like the one below.

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

Thank you Giggz, and everyone else, you are all my angels on and off the waves, Giggz, I am so thankful for your attention to detail and for being so thorough in your explanations, because of my new career I only sleep 2 to 4 hours a day for the last 8 years and being self-employed means I don't work I don't make money but right now I have time even though I am injured, so my brain is not as sharp as it used to be I lack experience and knowledge in the mechanical world, but with your explanations you make it sound simple and it clearly paints a picture in my brain.

Do you want me to use Loctite/thread-lock or should I use what I bought which is the ultra copper high temperature RTV silicone???

 

[Jiggz]

Re: 89 Force 50HP turns on and stays on only on high idle start

You can just use the one you bought since the real thing that holds the insert in place is when it is swagged on its knurled end. The loctite or RTV in this case, is only to hold it temporarily so when you unscrew the plug (which you used for installing the insert into the hole) it will remain in place and not unscrew with the plug. However, if you want to you can also use Loctite's 2620 hi-temp thread locker/ sealant.

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

Jiggz, Thanks so much, I've been dealing with IRS and taxes issues and have been held up as that is priority.

-- I kinda feel I trust more the locktite since I've used different ones and I know some of them are medium or permanent - in this case I want I make sure it is not only properly sealed for leaks but also tight for life, which is the reason for my question as to which one to use.

-- should I also do an insert on the bottom plug? Since everything is off now and as preventative measure since I should change my sparkies every year?? I have not dared to remove the bottom one to check, but after last compression test ad the new plugs I replaced it with is the reason for the damage along with an inexperienced new boat owner some damage may have been caused to it, so I thought I should remove the new sparkie and check and correct no matter the damage.
-- I also want to make sure that when I install the new insert I will use the sparkie to thread it in but that I will also leave the sparkie in the insert for the 24 hr curing period. That's how I understood, please confirm.
- please let me know what you guys think! Thank you ahead.

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

Is - Loctite's 2620 hi-temp thread locker/ sealant - the most permanent, strongest and resistant to both oil and gasoline?? The copper silicone sealant I was told at the store that it is resistant to oil and gasoline and it's high temp rating is 700 degrees F.

 

[pnwboat]

Re: 89 Force 50HP turns on and stays on only on high idle start

The Loctite 2620 is a better choice for your application. This is used for threaded bolts or any type of threaded fastener etc. The copper silicone sealant is more suited for a lower pressure gasket type application. Not typically used for the high pressure that the spark plug threads would be exposed to.

 

[Jiggz]

Re: 89 Force 50HP turns on and stays on only on high idle start

The hi-temp silicone is specifically designed for high temperatures as claimed in its packaging but it is not designed for high pressure or has the strength for adhesiveness. The 2620 is designed for both. For spark plug use, 2620 will be perfect in two ways: stand the heat and help hold the insert in place when torquing or removing plugs. I understand the insert has knurled top to keep it in place but if improperly swagged may not hold properly. So I recommend the 2620 as a backup.

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

Thank you guys. I don't have that locktite so I shall buy it.
-- Also - could you confirm wether or not I leave the sparkie inside the insert while it cures the 24 hr period? Or do I only use it to thread the insert in and then unscrew and let it cure without it??
-- should I do both sparkie holes at the same time? My thought is - the head cover is out so might as well do it.
-- Big question -- should I take off the the actual cylinder outer plate and re-seal? With what exactly cuz there is no gasket for it, so what do I use?? I want to make sure everything is sealed to perfection to avoid loss of compression an to eliminate any possibilities specially while the head is off.
-- Could I use the copper silicone sealant I bought? Or do you recommend something specifically?
I understand I should not use any gasket maker or sealant for the head gasket.

- I ordered a new head gasket, thermostat and gasket, fuel pump diaphragm and gaskets and should all be here by Tuesday afternoon. Any additional recommendations for those - after you first educate me on the above questions???

 

[Jiggz]

Re: 89 Force 50HP turns on and stays on only on high idle start

If you can unscrew the plug without the insert coming off with it, then do so just make sure the insert is properly located or centered from top to bottom. Otherwise, you can just leave the plug overnight and then unscrew it the next day. Remember apply the loctite only on the threaded section of the insert and never on the knurled area. The knurled area should be properly swag to ensure it has ground continuity with the block.

If the other plug hole is not stripped or cross threaded, there is no reason to fix it. Remember the insert may sound great but it is absolutely no better than an original plug hole for strength and reliability.

No you do not need to take off the cover off the cylinder head unless you see water leakage. The cover does not support any compression pressure instead it is just for the water passages.

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

Wow Thanks again! What an important detail about not putting locktite all over the insert, I "always" over do things and I would have definitely covered it completely without thinking about the grounding, what a lesson this is for me! Specially cuz I was going to do it yesterday but I had to postpone it. Wow thank you for educating me.

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

Good morning guys! I've been so busy but I'm back.

- new status - I could not find the Loctite 2620 anywhere so I had to special order it. Now I got it - it costs $40 plus the insert costs $35 for a total of $75. A new head cylinder cover costs almost $200. I found a used one for $45 or technically $35 with my $10 coupon. But I also bought my self a used power head for only $300 and a super great guy at northern lakes marine in Minnesota and the motor head has a leak down test result of 4% so now I'm faced with the following questions-----
- do I just buy the used head cover for $35 and return the repair kit for $75? I may not be able to return the $40 Loctite.
- do I just swap the power head with the used 1991 I bought?
- do I use the same exhaust gaskets I put on last month? Could I simply use some light gasket maker that will not be silicone and will dry hard?
- I got a new thermostat kit and a new fuel pump kit.

--- I found some pitting on my original motor's cylinder face and two bolts not as tight along with some water in the lower cylinder and I also feel both pistons move a bit when I move them as they sit on the cylinder so either I complete that project by buying the used cylinder cover instead of repairing the sparkie hole and using a new head gasket to then check the compression and see if it improves from the 90-93 that it has had since I bought it and have not ever really used and since I bought it it only did 10 MPH and then bogged out and died.
--- or do I just swap the head, using the month old exhaust gaskets and continue testing why it seems that only one sparkie is firing and not staying on?

Please advice. I would like less worries about my existing power head and it's compression and finally use my boat after owning it for more than a year and half and only fixing issue after issue.

 

[pnwboat]

Re: 89 Force 50HP turns on and stays on only on high idle start

- do I just buy the used head cover for $35 and return the repair kit for $75? I may not be able to return the $40 Loctite.

I would return everything if possible. The replacement power head should have everything you need.

do I just swap the power head with the used 1991 I bought?

That's what I would do. The original engine had low compression. A motor with 4% leakdown should have better compression.

- do I use the same exhaust gaskets I put on last month? Could I simply use some light gasket maker that will not be silicone and will dry hard?

How bad do you want to prevent having to remove the power head to re-do the exhaust gasket if it doesn't work. If not a big deal to you, then reuse it or try some gasket maker. Otherwise get a new exhaust gasket.


Good luck with your project!

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

Pnwboat - thank you for that confirmation. I will do exactly what you said. Start fresh with this power head, out in the new thermostat, the new fuel pump kit, the new upper/lower exhaust gasket instead of using the same ones and use a light film of gasket maker with it, how ever as I started taking everything off I have discovered the following;

-- I have damaged another fly wheel key. It was for sure installed properly last time I bought the new key. I will include pictures of the damaged key and also the flywheel and the shaft it sits on.
Note - the old flywheel key never really sat on the shaft tight and that is why I used some anti seize cream to hold it in place but you guys said it should sit there snug without needing anything I hold it, well the new power head has a key and it's pretty nice and tight on the shaft SO - could the flywheel have damaged my original shaft and I should replace it to prevent damage to my new shaft? Or could it be vice versa and the shaft not holding the key tight could have danaged the flywheel and since I got a new one it should be ok?? Please let me know what you guys think ???

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

 

[pnwboat]

Re: 89 Force 50HP turns on and stays on only on high idle start

Looking at the grooves in the hole in the center of the flywheel, I'd say it has sheared the key at some point in time and been spun on the snout of the crankshaft. There are some pretty good groves in the walls of the hole. You could try it as is, but I think there is somewhat of a risk that the key may shear again. To be 100% sure, you might start looking for another flywheel. You need one for a 1987 - 1991 50 HP motor that uses the Prestolite ignition system. Might try the WEB site that you got the motor from if you know what I mean, but I don't see any right at this moment that are reasonably priced.

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

I agree. I want to do things right from the beginning. I think the new shaft is in perfect condition holding the key tight and a flywheel it's much easier to change than the shaft. I just wanted everyone to see the pictures and agree or share an opinion.