Back into the 1989 85hp rebuild

[lgaytan]

So there's another thread were I've been working on the rebuild of this motor, it all started with low compression I just changed pistons that were damaged and rings and honed the cylinders, got it back to 110, 120, 120 psi with only this. In the first try I didn't got any power I could idle and low revs but nothing above 1500 RPMs, I knew I had a bad exhaust seal so I decided to tear the motor again and change that seal, today after two years of didn't wanted to know nothing about this I finally put it together back again, it idles strong, same compression so everything was ok until... After the compression test and reinstalling the spark plugs the second spark plugs threads stripped out!!! I don't understand this so now I believe the cylinder head is gone!
Here comes the question, the spark plugs are attached only to the head right so only by changing that I should be ok it is part number F630518? The diagram in Marine engine confuses me a little bit.
And also Jerry is you see this I still have issues with the stater fluid test, that is getting me crazy part of this second tear down was too change seals in the intake ports but that didn't help, any advise is well received.

 

[racerone]

Put a helicoil in the plug hole.----And cylinder head does NOT need to come off.

 

[jerryjerry05]

Starting fluid test: Can of SF, start motor and run at idle or just above idle.
Then spray SF around the intake side of the motor. Motors divided into intake side and exhaust side. The intake side is(looking at the carbs) the left side of the motor and under the ignition equipment. The packs and coils and the intake manifold and under the flywheel is where you spray.
If spraying the SF makes the motor run ANY different(cough, stutter, stall) then it's sucking air and the gasket/s need replacing.
Under the ignition is the 4 port covers( the 3rd one runs the fuel pump).
The factory gaskets weren't the best and 1 tiny cough, backfire, sneeze can blow out a gasket, maybe 2 ???
Good luck with your test.
If needed?? send a PM and we can exchange numbers.

 

[lgaytan]

Put a helicoil in the plug hole.----And cylinder head does NOT need to come off.

I thought about that, but then found a head at $30 USD, I just ordered that one seller claims it's flat, mine already passed an over heating years ago so I think maybe the change will also help.

 

[lgaytan]

Starting fluid test: Can of SF, start motor and run at idle or just above idle.
Then spray SF around the intake side of the motor. Motors divided into intake side and exhaust side. The intake side is(looking at the carbs) the left side of the motor and under the ignition equipment. The packs and coils and the intake manifold and under the flywheel is where you spray.
If spraying the SF makes the motor run ANY different(cough, stutter, stall) then it's sucking air and the gasket/s need replacing.
Under the ignition is the 4 port covers( the 3rd one runs the fuel pump).
The factory gaskets weren't the best and 1 tiny cough, backfire, sneeze can blow out a gasket, maybe 2 ???
Good luck with your test.
If needed?? send a PM and we can exchange numbers.

Will try in a few weeks when the new head arrives, I already order it. I'll send you the PM if in trouble,thanks for the offer.

 

[lgaytan]

I have put the motor back together, I was very detailed in putting back the intake manifold, I checked to see if it was twisted but seems to be ok , I used double intake manifold gasket see if it improves the sealing, I had bad reed plates gaskets and didn't wanted to wait to order replacements so I did my own gaskets I think I did them well. Anyways I started up the motor did the stater fluid test and still can notice the motor reacts to that. Questions: Is there a torque sequence? What torque should I use according to the service manual it is 70 in lbs for 1/4 - 20 screws, could I go higher or that should be it?

 

[lgaytan]

Not bad.

 

[racerone]

How did you do the starter fluid test.----What did the motor do ?----What did you learn from that test?

 

[lgaytan]

I sprayed the back of the carbs and the intake manifold, spraying behind the lower carb right side looking from the carb side the motor starts to rev down, it didn't die but rev down, according to what Jerry told me that is bad seal that needs to be fixed, after that I retorqued the intake manifold screwed to just a little above 75 in lbs but results were the same. Motor starts with no issues and idles good but last time that I tried it in the lake I couldn't rev higher than than 1200 RPMs and I been trying to fix this since then.

 

[racerone]

It is NOT a gasket leaking !---Find the real problem.-----I say it is running on 2 of 3 cylinders.-----Did you clean the carburetors ?----Does spark jump a gap of 3/8" on each lead?

 

[lgaytan]

Spark does jump 3/8" last time I checked, I can do it again to make sure nothing changed, I also cleaned carbs, how can I test if it is running with one less cylinder?

 

[racerone]

Check fuel pump diaphragm.----Start motor and run at a bit faster than idle..----Pull one plug lead off at a time.----Note the results.

 

[lgaytan]

I changed the pump diaphragm recently also, that should be ok.
Ok I will test by removing the plug leads, that doesn't damage the coils? I have been always afraid of doing that and also to receive a shock.
In my mind my the issue is a fuel issue, but as I rebuild the pump recently I just don't know where else to look, the only thing that I noticed was the issues with the starter fluid, anyways I will keep investigating, I'm determined to make this motor run good even if it takes me time.

 

[racerone]

If you can obly get to 1200 RPM there is a serious issue.----Should not be hard to find it.

 

[lgaytan]

thanks, I will try and inspect again fuel lines, fuel pump, the spark etc what is mentioned above, this weekend I will try it in water I will take video to share for your thoughts.
Also just for the record compression is 110 - 120 - 120.

 

[lgaytan]

Did spark test today cylinder#1 with the spark tester I got spark on all three cylinders but #1 didn't looked even, so then I turned on the engine and unplugged the plug lead while running and I didn't see difference, I think I have intermittent firing, definitely something wrong there. I see the three coils and two blue boxes, do they work together? Can I just changed the coil? Is there a way testing the coils and this blue boxes?

 

[lgaytan]

After reading some older posts I think I should start by swapping components to try to identify the faulty component.