85 15 hp..issues

SCduckhunter

Seaman
Joined
Sep 9, 2013
Messages
64
Re: 85 15 hp..issues

Ok..so,I tested the fuel pump today..it's not leaking at all....it was hard to start and idled poorer than it has lately...defiantly not fuel lines or tank or primer pump bulb..used know working amd have all new fuel lines....I can run another compression test but all previous have shown 104# or better with not more than 4# difference....at a lose here....reed valve? I wouldn't think they were bad but don't want to get into that if it's something simple....thanks for all the help thus far..I'm sure we are all just as puzzled and I'm frustrated
 

OptsyEagle

Lieutenant
Joined
Sep 13, 2006
Messages
1,359
Re: 85 15 hp..issues

After work today i ran out and it cranked up no problem....i let itwarm up and when it started to run bad i shut it down and unplugged#1 plug it ran real rough... switched it to unplug#2 and it ran decent....i flipped plugs around and retested.. it did the oppisite

Am I following this correctly. You are saying that cylinder #1 ran well and #2 didn't. You then JUST moved the spark plugs into the opposite cylinders and now cylinder #2 runs well and #1 runs rough. Sounds like a spark plug issue to me. I will ask the question again that another poster asked already, what spark plugs are you using and have you replaced them since you did this test? How did it run? What did the spark plugs look like? Both the same, one oily and black or one clean as a whistle? This is how your motor talks to you.


after i did an air gap spark test with engine at temp spark was defiantly weak on #2.. replaced coil pack and put plugs in her at .30 this morning

HOW WEAK was the spark on #2? What were your observations during the external spark test? How much air gap could each jump? More importantly, did the spark test results change when you changed the coil pack? 2ndly, when you say you changed the coil pack, do you mean you changed the spark plug coil or do you mean you changed the powerpack?

Another time you stated this:

ran it today after a carb cleaning 2nd this week....it fouled the #2 plug pretty good within 10 mins...it is respomding to throttle....now it just surges and wants to get up and go..it just wont....

When you ran the air gap spark test and confirmed that the #2 cylinder was weak, you should then switch the spark plug boots and clips and run the air gap test again and see if the problem moves to the other cylinder. This will help identify or eliminate the coils as a culprit.

I am having a hard time following you. In the beginning the motor idled great but would not provide top end power. Now it seems to not want to idle well. In any event it seems to me that you have a spark issue. Either the wrong spark plugs, bad coils, bad powerpack, or a problem with a wire, etc.
 

SCduckhunter

Seaman
Joined
Sep 9, 2013
Messages
64
Re: 85 15 hp..issues

The power pack was received Saturday and installed Monday with new champion plugs..QL77JC4 gapped at .030...I tested it in drum and it idled pretty well and fired up..this is all post overheat rebuild..when I first tried to fire it 10 days ago after the overhaul it had no spark..after testing all the loads and what not it was determined that power pack was the culprit of lack of spark..ordered it and installed Monday past. After initial running, I took it to river and that's when I discovered that it didn't reach full RPM at WOT and was extremely slow o respond to throttle... I returned home and checked the brand new plugs...#1 was clean # 2 was dirty. I performed another compression test.. Results posted above...I believe it was 108# both cylinders...so Tuesday before work I was out toying with it and after swapping plugs around and trying to find anything obvious I may have missed I decided to do an air gap test...#1 jumped big time no problem there...#2 hardly jumped at all... I could barely hear it or see it....power pack is now ~24 hours installed...was off Wednesday so I ran it again after the new coil pack install that I purchased that morning cause it was local in stock... Ran it in the river and out of the gate it sounded healthier and when I gave it throttle it wasn't nearly as sluggish as Monday.. It nearly was back to pre overheat performance... After some running it would surge to full rpm for brief periods....it also responded to throttle well...I went to trailer it..it responded so well that I power loaded and unloaded it multiple times after pausing in N ..it ran nearly like it should just not top end...while surging I pumped primer bulb ..no change I removed gas cap and pushed and pulled on lines ...I ran it for nearly 2 hours...I pulled plugs and #2 was dirty again... I believe that's when I went and bought 2 new ones again (1.99 apiece cheap enough to have new ones on hand) installed and returned to river...same result and #2 dirty again after short use....i checked fuel pump for a leak today ...other than that I haven't changed anything.. I run out crank it let it run a bit and shut it off (always in a drum..I park in front of the drum to flush motor after every use..it runs in saltwater a lot ) the idle is poorer when stone cold in the mornings and it's harder to start...I can let it run for a few minutes shut it down and the rest of the day it'll crank with hardly any effort..it just seems like a simple issue and can't figure out what it is..after the long slow overhaul process it's really disheartening to be so close yet so far
 

OptsyEagle

Lieutenant
Joined
Sep 13, 2006
Messages
1,359
Re: 85 15 hp..issues

A couple more clarifications. When you air gap tested for spark was that with an external spark tester or just grounding the spark plug against the powerhead and pulling the starter? Also, when you say a plug is clean or dirty. Does clean mean a regular tan color of a good firing plug or shinny white and possibly wet with water. Does dirty mean the regular dirty tan color of a good firing plug or a wet oily cruded up color of a rich or non-firing plug?

In any event, what I would do is perform another external spark test on both cylinders to ensure the ignition can provide a voltage strong enough to jump a minimum of a 3/8" gap. If one of the cylinders fail this test, I would switch the coil plug boots and switch the coil clips and then run the same external spark test again to see if the failure switches cylinders. If it does switch I would look closely at the coils for the culprit and if it doesn't I would look closely at the powerpack.

If both cylinders spark can jump a 3/8 gap then we must have some other, probably more weird problem happening.

Another question I had is how was it determined that the old powerpack was failing?
 

SCduckhunter

Seaman
Joined
Sep 9, 2013
Messages
64
Re: 85 15 hp..issues

We followed the test procedures in the seloc manual with an ohm tester and such...my father in law owns an auto body shop and has nearly every tool and tester in the world as he also does some automotive mechanical work...he and I did the tests together and after two days with the motor he determined it was the power pack..he's hates throwing money and parts around without knowing what the real fix is..it's rather annoying sometimes....as for another air gap test not a problem will do that as well as change coils to the other cylinders....the plugs..I've bought two sets int the last 8 days..the top cylinder looks clean not new but like a proper good running engine..not enough time on it to create any real discoloration...maybe a slight tint of brown..defiantly not wet...the bottom cylinder well..after ten minutes the electrode looks like I ground it into a lump of charcoal...50:1 oil to gas ...non ethanol marine fuel only... In the last year we have replaced all fuel lines with ethanol approved lines and replaced fuel pump after a failed rebuild ( again he doesn't like throwing money and parts at stuff) he can't figure if the #2 is flooding or misfiring...just lost lol..again the power pack at this point has been installed 4 days....so that's not likely the problem...my biggest fear is that when motor locked up during overheat ( due to collapsed upper water tube grommets) it may have damaged a piston ring..it hasn't shown up on compression test
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: 85 15 hp..issues

Ditch the Q plugs. Use L77JC4. The Q suppression plugs, in my experience, tend to cause problems in the smaller motors.
 

OptsyEagle

Lieutenant
Joined
Sep 13, 2006
Messages
1,359
Re: 85 15 hp..issues

OK, thanks for that. Let us know the results of the external spark test so we can determine how this motor's ignition is firing. It kind of has to be the coil or the powerpack or a damaged wire or poor ground. Almost everything else feeds both cylinders and it appears that your bottom is the culprit. If both cylinders are sparking good and you have the ability to do so, fire the motor up and let it warm up and run the spark tests again. The coils can sometimes be intermittent problems that surface when they get hotter.

Also, if you run it again, take off the air silencer and see if any fuel is being spit out the carb throat. That is a symptom of a faulty reed valve, one that is stuck open. Another possibility.

I believe you said that you changed all the gaskets. I suppose that means that you removed the cylinder head and took a look inside for scoring or damage. Did you resurface the cylinder head to remove any warpage? Have you re-torqued the head bolts. I agree that most issues here should show up in your compression numbers, so I wouldn't spend too much energy on it, at this time.

Lastly, when you pulled the powerhead to change the upper water grommet, did you change out or look at the lower crankcase seal?
 
Last edited:

SCduckhunter

Seaman
Joined
Sep 9, 2013
Messages
64
Re: 85 15 hp..issues

We resurfaced all gasket mating surfaces and had a friend who is a marine mechanic from out of town look at the cylinders and piston and such..he also looked over the rest and said that what we were getting into and doing looked to be all that was needed..if not a bit more...When doing the head we used a rubbing compound and a flat piece of glass and rubbed it around on that...Lower crank case seal was replaced since we were there...I will do the reed valve test when i run it monday morning....Im going to try and swap the plug leads from the power pack to the coils...I cant be certain i put those on in the correct order...I know i put the lead with the slight bit more length on bottom coil so i may have them on incorrectly....Whats the proper way to mount the coil packs ensuring grounds and such??..I did see 2...just 2 blue sparks on the back of the head last night...near the #1 plug wire...Im not sure as it was sudden and i saw the second spark after hearing it pop the first time....The motor runs just not great..on a scale of 1-10 its idling about an 8 and while under a load and moving aside from not getting up to full RPM and surging up to full rpm a 6...i will be duck hunting out of it monday so i will do the reed test then...thanks for all the help so far...
 

SCduckhunter

Seaman
Joined
Sep 9, 2013
Messages
64
Re: 85 15 hp..issues

Q plugs ditched this morning no change still idles at an 8 of 10...It did hardly start when swapping coil leads from power pack to coils around...so i must have had them hooked up correctly...i didnt hear or see the spark this morning doesnt mean it wasnt there however
 

OptsyEagle

Lieutenant
Joined
Sep 13, 2006
Messages
1,359
Re: 85 15 hp..issues

If you were worried about whether you had the right clip on the right coil you need not. The fact that it started at all would indicate you did. If you reverse the clips you will be firing at "bottom dead center" on both cylinders. You could pull the rope till the cows come home and she will never go, that way.

I can't stress more that when doing a spark test you need to use an external spark tester. One where you can set a gap for at least 3/8". If the ignition is not strong enough to jump that gap you will have problems...like the ones you are having. If you are just grounding the spark plug against the powerhead, even if you see a good spark it doesn't mean it is working when under compression. It takes a tremendous more voltage to create a spark under compression then it does in ambient air. If you are using an external spark tester then forget what I said. If you are not and do not have one, then just make one like this. The top of that piece of wood is metal for the ground and the spark plug boots just clip onto the 2 respective bolts. Position the bolts about 3/8" from the metal top and give the starter a good pull and look for spark.
 

Attachments

  • spark_tester.jpg
    spark_tester.jpg
    148.8 KB · Views: 0

SCduckhunter

Seaman
Joined
Sep 9, 2013
Messages
64
Re: 85 15 hp..issues

Yes i am using an external spark tester..getting aprox 1/2 spark jump or better..its throwing a lightening bolt...I was referring to a spark i saw at night when i ran it..Well i heard it pop and looked to see it pop again..it was brief so i couldnt pinpoint it..it looked to be near top cylinder boot..maybe..again it was brief..I believe yall have me on correct path..What is correct mounting order/procedure for mounting coils?? I took tons of pictures upon tear down and camera happened to not save a dozen or so and the coils were among that dozen..Im continuing to investigate the coils and spark...with the new non Q plugs ill fire it up when i get home and really look hard at it since had to leave for work after install and brief firing this morning...Again thanks for all the direction
 
Last edited:

OptsyEagle

Lieutenant
Joined
Sep 13, 2006
Messages
1,359
Re: 85 15 hp..issues

I can't help you on the mounting order for the coils, since yours are a little different then mine. You do want to make sure that wherever the ground is made for them that it is very shinny. Especially for cylinder #2.

The other thing to look at when you are near the motor is the throttle cam's synchronization with the carburetor. As you turn up the throttle a cam on the timing plate comes along and pushes on your carburetor's roller. There is usually a mark on that cam that must be in the middle of that roller JUST as it touches the cam. This sets up your spark's timing advance for all the RPM ranges. If it was out of sync it would not only effect your top end performance but also your idle.

I didn't mention it before since it would effect both cylinders in the same way but since you seem to be getting good spark, perhaps that good spark is just not very well timed. Anyway it is an easy check.
 

SCduckhunter

Seaman
Joined
Sep 9, 2013
Messages
64
Re: 85 15 hp..issues

The first time i ran it i actually thought that maybe we advanced a tooth on the throttle gears..ive seen the mark your talking about and looked at how it interacted with the roller..as far as i could tell...ive sanded all the areas behind the coil packs...the bolt seem to be the grounds...
 

SCduckhunter

Seaman
Joined
Sep 9, 2013
Messages
64
Re: 85 15 hp..issues

Mystry solved...whike out hunting this morning motor ran well asidefrom no top end..did everything i asked it to...on my return to the landing it started bogging and i then heard a metal ticking or slight rattle....went to father in laws shop and did a compression test 108# on #1 cyl... ~80# on bottom rut roh...he said the head gasket didnt fix it so its deeper.....@930 i pulled into a work bay and at 1 i dropped the block off at the machine shop for cylinders to be honed....he quoted me 25$ over the phone..when he saw it he adjusted the quote to 15$ told me it wasnt bad at all and that it wouldnt take much to hone it...it looked as though a ring was partially broken...the piston itself has some scoring on it...was told ( he knows better) if its a 30$ piston to replace it otherwise rings are all thats needed...im planning on doing all the bearings.. alot depends on cost i dont want to spend more than like 200-250$ on parts....nbody know best place to get correct parts?
 
Top