9.9 Evinrude- spark yes, gas maybe, compression not so much

[David Foe]

This is part two of a question posted earlier this month. I have spark and I replaced the head gasket on my now un-seized 9.9 Evinrude from 1982. The compression numbers are still grim (60 and 90 psi) but I understand that it should start even with those poor numbers. It doesn't. I got it to catch a few times but there was none of the roar of power that I was hoping for. Here are some symptoms ,,, any comments (including "it's an anchor") would be welcome and appreciated.

(1) I know that the lowest compression number (60 psi) is due to a stuck ring. I know this because I removed the exhaust port cover and, after poking all the rings with a popsicle stick determined that one of them is stuck. I have used the usual things (PB blaster, mystery oil etc) to get it free but I am probably looking at a ring job but my hope is that I can get it running long enough to shake the ring free.

(2) After pulling on the starter rope a few dozen times with the throttle roughly in the spot where start would be, I got it to cough a few times and run for one or two sec or so. A few more dozen pulls and nothing. I still have spark but when I squeeze the primer bulb I think I can hear gas gurgling into the carb but appears that gas is leaking from somewhere in the carb. This is obviously a problem, where do I start ... does it mean a complete carb rebuild or could the float valve just be stuck?

Thanks for any advice!

David

 

[Rick.]

Re: 9.9 Evinrude- spark yes, gas maybe, compression not so much

If you have a stuck ring a seafoam treatment will perhaps loosen it better than any thing else you might try. What to do? I would get some gas mix in a squirt bottle and try spraying some gas into the carb. as your pulling the rope. If your not getting gas normally this method will indicate that. You could do a carb. kit now but try the squirt bottle first. What about your slow speed needle? It should be 1 1/2 turns out from gently seated. Make sure your plugs are gaped to .030 and your points to .020 (if it has points). The points need to be very clean as well. Let us know how you make out and tell us the year of your motor as well. Best of luck. Rick.

 

[David Foe]

Re: 9.9 Evinrude- spark yes, gas maybe, compression not so much

Thanks Rick.

(1) 1982 9.9 Evinruide.

(2) I will definitely try squirting some gas into the carb. to see what happens.

(3) My concern is the leaking gas from the carb -- I suppose it means that there is a broken seal somewhere and the carb will have to come off. Once off, a rebuild seems sensible (will be my first time doing a carb rebuild).

(4) I'm not sure yet where the slow speed screw is but I haven;t changed anything on the carb so I am assuming it is roughly correct.

Thanks all,

David

 

[SeaKaye12]

Re: 9.9 Evinrude- spark yes, gas maybe, compression not so much

So; you see gas dripping out of the carb? I've had pretty good luck on a variety of motors just by tapping on the carb; often seems to free up the needle valve so as to (at least temporarily) seal off the fuel flow after the bowl is full.

A ruptured fuel pump diaphragm could also be the culprit; although instead of seeing gas drip from the carb; fuel could be flowing into the crankcase.

I understand that your primary goal is to see if the rings can free up with a bit of run time...and that you might not want to be rebuilding carbs and doing other service until to get the engine to that point.

After that; a full carb rebuild would be in order of course.

Good luck, Chuck

 

[David Foe]

Re: 9.9 Evinrude- spark yes, gas maybe, compression not so much

Thanks! Tapping on the carb, that I can/will do. I am sure that the gas is dripping from the carb so a stuck needle valve seems likely. I'll let you know what happens.

Question ... When one squirts gas into the carb, does one remove the air intake to expose the carb air intake and squirt 4 cc's (more/less) ?

Thanks,

David

 

[kbait]

Re: 9.9 Evinrude- spark yes, gas maybe, compression not so much

You can squirt it through the hole where the low speed needle knob is(once removed). Make sure your low speed needle is 1.5 turns out from gently seated. If it's now set at less than one turn out, turn to 1.5, and try it again w/o the squirt test first. That may be it..

 

[David Foe]

Re: 9.9 Evinrude- spark yes, gas maybe, compression not so much

I think I'm getting close (thanks to advice found on this site) I feel that I am close but something is not right (in addition to the low compression).

So here is what I now know:

(1) Adjusting the idle scew 1.5 turns from seated helped, I think, because I got it to run for maybe 2 sec instead of 1. Thanks for that tip!

(2) Squirting 2 cc's of gas into the carb (I had to take off the air intake) didn't make a noticeable difference. I'm not sure what this tells me.

(3) The carb might be ok, I found that the "leak" is actually from gas squirting out of a hole on the side of the carb (next to the idle adjust shaft) that sends the gas overflow from the bowl into the air intake where is pools but if too much pools up it leaks. Am I understanding this correctly?

(4) I am setting the start throttle by following the machinist's advice to someone else, roller just touching the plastic extension to the timing plate (or whatever you call that thing) then adding 3/8" Are there any other adjustments needed? What about that round black screw thing on the left side of the engine housing -- can that mess up the start if it has been turned a fair bit?

Any advice would be most appreciated!

David

 

[Rick.]

Re: 9.9 Evinrude- spark yes, gas maybe, compression not so much

Well 2 seconds won't cut it. LOL. The 1.5 turns out is your start point. You can keep turning it out in 1/8th. increments and see if it helps. The knob on the port side is your idle speed adjustment. It is a wonder feature if you like to troll. It is a slow speed cruise control of sorts. For now I would just back it off and play with it once you get running properly. Rick.

 

[David Foe]

Bad News!

Bad News!

I finally "manned-up" and I took the carb off to see if I could give it a quick clean and, voila, I found the problem. The steel float bowl was so rusted and the rust volume so great that the float was held in place by a solid block of rust! As a bonus, I also found the leak, the bowl has rusted right through in several places. Why oh why didn't I take the carb apart sooner?

edited:

A quick look for a replacement bowl and I see one place sells replacement bowls for about $30.00. Now it's decision time, go forth or abandon the thing.

Thanks,

David

 

[kbait]

Re: 9.9 Evinrude- spark yes, gas maybe, compression not so much

Tim's outboard may have a used bowl. 218-682-2331.

 

[David Foe]

Re: 9.9 Evinrude- spark yes, gas maybe, compression not so much

Thanks, I'll give them a call