1975 evinrude 9.9 fuel pump prob?

[bktheking]

Re: 1975 evinrude 9.9 fuel pump prob?

Did you seal the top welch plug on the carb?? I'd say try another carb on it, could be the driver coil, who knows, i'm out of ideas???!@??!?!?!?

 

[scanman]

Re: 1975 evinrude 9.9 fuel pump prob?

I put the welch plugs in dry & "set" em with the butt end of a cold chisel. Do they get a sealer of some type? Don't have another carb to try, I asked both of my friends. Kinda blows bein new in town.

I'm gonna have a crawfish & horseshoes party with a bonfire when this thing gets right!!!

 

[OptsyEagle]

Re: 1975 evinrude 9.9 fuel pump prob?

I can't help you with the driver coil only to say that it seemed like it was the only ignition part not really checked and I suspect if it was faulty you would have some kind of spark problem. I know the secondary coils can act up when they get warm and so perhaps the driver coil is doing the same. Unfortuneately I do not know the symtoms of a bad driver coil or how to test it.

It just seems to me like it is a timing issue, but why it would get worse as it warms up is a mystery to me. I seem to remember that the spark advance sequence is something like a little past TDC for starting and idle, since I think they start easier that way and then as you throttle up it advances to TDC and then a little more before TDC and so on, as your RPMs go up. If I am completely wrong, please someone tell me. If it was advanced further up where the piston is too far down when it sparks for idle but is advanced back a little for higher RPMs then it would make sense that it could still run at faster speeds with more gas, but die at idle. I would think it wouldn't run all that well at WOT under those conditions either. Now how it might get that way, is still a mystery. Perhaps it is that loose timing plate that Leeroy talks about.

My head is hurting on this one as well.

 

[OptsyEagle]

Re: 1975 evinrude 9.9 fuel pump prob?

I put the welch plugs in dry & "set" em with the butt end of a cold chisel. Do they get a sealer of some type? Don't have another carb to try, I asked both of my friends. Kinda blows bein new in town.

I'm gonna have a crawfish & horseshoes party with a bonfire when this thing gets right!!!

I seal mine with that 3M #847 material, if you have some or even permatex 1 would work. I think you could add that around the perimeter with it still on your motor, if you wanted to try it. It just goes around the edge of the welch plug to ensure a total seal.

 

[bktheking]

Re: 1975 evinrude 9.9 fuel pump prob?

Clear nailpolish works for me, wife loves it. As for the timing plate, I have a good one with a driver coil, yours free to try it, if it works then keep as a gift from the BK fund, I even have a spare plastic bearing.

 

[scanman]

Re: 1975 evinrude 9.9 fuel pump prob?

I'll certainly add some permatex to the plugs, it can't hurt!

Thanks to everyone for lettin me share my headache with yall!
I might be a chief of the boat before this one's done!

 

[bktheking]

Re: 1975 evinrude 9.9 fuel pump prob?

I just wanna make Admiral, the "rear" part adds a certain level of complexity to my rank which is simply a character misrepresentation.

 

[Will Bark]

Re: 1975 evinrude 9.9 fuel pump prob?

Scanman; here's one more probably crazy thought, id it possible that exhaust fumes are being sucked into the carb which would kill it? have you tried to run it on the muffs so there is no back pressure which could force exhaust fumes up to the carb from a leaking exhaust gasket? I know this is crazy but if not ignition, compression or fuel what else is left?

 

[scanman]

Re: 1975 evinrude 9.9 fuel pump prob?

It gave me the same results when I tried to flush it with the muffs after a trip on the bayou, plus the exhaust gaskets (upper & lower) were replaced during rebuild. I was forced to buy em. Not much left of the old ones. I also tried puttin a fan in front of it, cause I've owned one of the late 60s models that are known for that. Also replaced the upper grommet on the water tube.
Bk, im not sure if "rear" would misrepresent me or not!

 

[bktheking]

Re: 1975 evinrude 9.9 fuel pump prob?

It was a joke, think about it "rear admiral".

 

[scanman]

Re: 1975 evinrude 9.9 fuel pump prob?

It was a joke, think about it "rear admiral".

Yea I got it, but the ole lady says it doesn't misrepresent me! She says it fits! We're still arguing bout it!

 

[AlTn]

Re: 1975 evinrude 9.9 fuel pump prob?

hmmmm...Scan, your throttle advance to timing plate looks exactly as the set up on the '78 I refered to..."sumpin' ain't rite"..<brillant observation>..have you tried a cylinder drop test ?...pulling each plug wire while it's runnin' to see if it'll run on one and not the other?..

 

[scanman]

Re: 1975 evinrude 9.9 fuel pump prob?

Nope, haven't tried that. It wont run long enough to try it. I'm gettin a driver pack & a flywheel key in about 2 hrs. Imma put one in at a time just so we all know what fixes it, if anything.

 

[OptsyEagle]

Re: 1975 evinrude 9.9 fuel pump prob?

The other thing you could try is when the motor warms up and then dies, is to test the spark strength as quickly as you can. I suppose if you can jump a 3/8" gap when it is cold and if it still jumps a 3/8" gap when it is warm, it would pretty much confirm that your driver coil and your secondary coils and condensers are all fine. The only spark issue left would be timing.

That being said, if you were real quick (before the motor cools down) you could try to get the compression tester in there and check the spark and cylinder compression at the same time. Test it all cold and then test it again when it is warmed up and failing on you.

 

[scanman]

Re: 1975 evinrude 9.9 fuel pump prob?

Thanks OptsyEagle, those are both good ideas. I'm gonna make a "before" vid this mornin & then test the spark while it's still warm. If I'm lucky, the driver pack I just brought home will do the trick. Then I'll make an "after" vid & post em both in this thread & a new one that might save anyone else from goin through all this trouble! I'll get started soon as everyone's awake here.

 

[scanman]

Re: 1975 evinrude 9.9 fuel pump prob?

Replaced the flywheel key this mornin, but it was no help. Now that's new. Got out the new driver coil & apparently I took the wrong part # to the dealer. Took it back & they didn't have the right one in stock. They said they wouldn't have it 'till Wed of next week. I didn't see one on e-bay today, either. Just placed the order for it at shop2.evinrude.com. oughtta be here Monday. I didn't get home in time to put the old one back before dark so I'll run the warm spark & compression test that OptsyEagle suggested in the mornin.

Thanks again yall!

 

[OptsyEagle]

Re: 1975 evinrude 9.9 fuel pump prob?

If your spark checks out OK at cold temperatures and hot temperatures, you might want to look at cancelling that order for a driver coil. I seem to remember that they are not cheap. If you are getting strong spark then I would have to assume that your driver coil is working properly.

If that is the case I would be leaning towards timing as the issue but if you could get the compression numbers hot and cold as well that might tell something about the internals like piston rings and such. Also a possibility.

 

[scanman]

Re: 1975 evinrude 9.9 fuel pump prob?

I'm goin out in bout 1hr to do both checks, warm & cold. I thiught bout cancellin the order last night, but I think I'd rather have it replaced. I've already had the " more money on that old motor? " discussion with the wife anyway. BTW the coil driver, from Evinrude, costs $56.25. $10.99 for s&h! They ain't usin flat rate boxes are they?

 

[AlTn]

Re: 1975 evinrude 9.9 fuel pump prob?

hmmm...went back and read your posts and #98 is sorta confusing...this motor will start,run in gear, and accelerate up to 4,800 rpm<although belabored> and the problem seems to be centered around it not wanting to idle and dies when the throttle is reduced to about low midrange from wot?..seems to me that the carb is the weak link. Did you remove the high speed orfice <jet> and clean it to the point of shiny?...the tube that's above it...with the holes...did you clean it really well?..the high speed orfice plug for a 1978 9.9 shows to be a no.38...with a part no.322752..somewhere on here I've seen a drill bit no. that equates to a 38 orfice opening and can be used to clean it, delicately I'm sure. This orfice is through which all fuel consumed must flow....soooo yeah, it's dang vital. Seems that you cleaned the idle circuit well...so this...is the float hanging at times, maybe on the bowl gasket?...I'd put the gasket on with the bowl screws, invert the carb body, and see how it looks as it swings. Do you still have the old float?..if so..I'd re install it and give it a go...I did this on a 6hp. as I couldn't even get it to start with a new float...old float in..cranked first pull and is running well a year later....just throwing out things to try while you await that charge coil...fwiw...I spent the better part of 9 hours trying to get the lower unit <driveshaft> back into the crank end of a 5 hp. ted williams gamefisher...76 model I think... for a friend of mine. It belonged to her Dad and was of sentimental value....sweet jesus it finally went in. The rest of the story is...they used it twice...she just wanted it to run again and it's been sittin' for a couple of years now...you're gonna get there, Scan

 

[OptsyEagle]

Re: 1975 evinrude 9.9 fuel pump prob?

There seems to be something conflicting with everything that could be wrong with this. If it was a dirty carb, then it should have kept running when he sprayed fuel into the carb throat. Unless that spray flooded it. Could try that test again I suppose.

It seems to me, that in one video, one cylinder started to fail and then the other (but that has not been proven). This seems like a spark problem to me, since spark and compression are really the only things that would affect one cylinder over the other, but then the other dies as well. Again, very confusing unless we are talking about a weak spark as opposed to no spark. That leads me to want to look at the driver coil, or perhaps both of his new secondary coils are defective. We now know the condensers are fine. If he had some old coils, he could temperarily replace those just for a test, but it is kind of a long shot. I seem to recall that his secondary coils are brand new.

The last thing, is that the piston rings are not quite right and get worse as the motor heats up, lowering the compression. One getting to the point of failure just before the other. I am hoping the hot and cold compression numbers can shed some light here, but I fear that 1) the numbers most likely will be different since they probably would be different on a perfectly working motor and 2) because of this, they will not tell us if there is a problem, even if one exists.

Now, that being said, it is possible that the problem is created by one cylinder failing and then from lack of idle gas (in the videos he doesn't seem to adjust the throttle too much to keep it going, although we know he can at higher throttle speeds) the other dies out.

Why does it run at higher throttle levels. That makes me think timing but I think he has checked the timing with a light and how does the timing get thrown out so much that he loses idle operation? Now this issue could lead us to the carb since at higher throttle levels the motor starts running on the high speed jet and at the lower levels it is using the slow speed jet. Question: How did the end of the slow speed needle look? Was the taper good and smooth?

Anyway, as soon as you rule a potential problem out, it comes back again.