89 mariner 115 problems on the water today

[JoshNorthernPA]

Got the boat out today after much work in the shop de-winterizing it. Put the muffs on at the house and started it prior to taking my boy out, started right up. Didn't run it for more than 10 seconds. Got it out on the water today and it would not plane up like it normally does. Felt unusually bogged down.. after letting it warm up good I matted the throttle and it pushed water for about 200 yards before finally coming up on plane..

Changes over winter were, put on a hydrofoil, took the bottom carb off and put new gasket in the lower brass screw as it had a slow leak. Cleaned all the spark plugs.

It almost feels like one or two of my cylinders iaren't firing. I know its not a switch box because i've had two of those fail and know how it acts when they do. This gets up to plane and up to speed but takes 5 times as long as it did before.. sounds like the engine is working extremely hard.. anyone have any help there?

 

[narvlebenoit]

Re: 89 mariner 115 problems on the water today

try some new plugs.an try pumpping the bulb while running if it runs fine while pumpping the bulb its probably the fuel pump.

 

[Puddy905]

Re: 89 mariner 115 problems on the water today

Clean the carbs

 

[JoshNorthernPA]

Re: 89 mariner 115 problems on the water today

So I called the guy at the marine place I took the boat to, he immediatley noticed my carbs were out of line and had them put back in place and did some other stuff and started the boat.. he said it ran fine.. i said did you do a compression check or spark check, he said no.. i said since i'm an hour away from you i'd like to get that done.. he did and was way off on his estimate of damages.. compression was 115, 95, 95, 110, 110, 125, with intermittant spark on #4. he said that usually indicates total engine rebuild.. I didn't want to sink that kind of money into an 89' 115 unless anyone has any other info based on this.. i tried the boat on the way home.. still only does about 3,000 RPMS and bogs way down on full throttle. Gets up on plane in 4x the amount of time.

 

[arsenalpsu]

Re: 89 mariner 115 problems on the water today

I wouldn't go to that extreme yet.....compression is supposed to be 10% or 15 worse case within each other, so you're not extremely far off. First look into your cylinders with a light, see if you have lost part of your crown- if not than it's your rings and I'd do a full decarb with a gallon of seafoam mix & spray some Deep Creak (seafoam in a spray can) directly into the cylinders- your old rings are square don't move like the new semi-keystone ones and can build up carbon, then not seal properly. Decarbing will help compression if this is the case. If you are missing any large portions of the crowns than overtime it will only get worse and you could risk damaging your block should a piston fail. If this is the case than it's time for a rebuild- if you have any mechanical ability you can do it yourself with the tools you already have-except for a fly wheel puller. (you don't need those special ring compressors) Will cost $300-$800 on parts depeding on your damage as apposed to $3-$4000 at the shop. OR I can give you the # of Wayne (inline expert on here) who will do a block swap with you for +/-$1100 or so, you just mail him your block and he sends you a rebuild one.

The main reason you're not getting the hold shot is your spark, not the compression. If you fix the spark and your pistons are good she could last a wile longer before needed a rebuild. (could be coils, bad switch box, trigger, stator or just a bad connection)

AND this is for everyone with an inline- put a BB in the small tubes above the carbs and remove the idle stabilizer box and throw it away.

 

[daveswaves]

Re: 89 mariner 115 problems on the water today

It is also possible that your high speed winding on the stator has opened up or gone higher resistance, that will cause a plateau around 2500 to 3000 RPM. If you are handy with an Ohm meter you can check CDI,s web site for a step by step troubleshooting procedure and resistance values. Look for damage on the crown of 2 and 3, particularly number 3.

 

[JoshNorthernPA]

Re: 89 mariner 115 problems on the water today

Ok, I'll look at the piston crowns today and get the seafoam coming. How do I rule out coils, stator, switchbox, and trigger? I have mechanical ability and work at a family Machine and steel shop.

Also can you post a link of CDIs website to do the Ohm meter check?

I'll let you know what i find out.

 

[daveswaves]

Re: 89 mariner 115 problems on the water today

http://www.cdielectronics.com/downloads/troubleshooting guide/

 

[JoshNorthernPA]

Re: 89 mariner 115 problems on the water today

Alright, made some headway on the issue today.. got new plugs and decarb foam spray at west marine.. did the change out and was back on the water today.. after about a mile of no wake idling I hammered the throttle only to have the boat bog down similar to what it was prior to the plug change.. i told my buddy to go sit on the front deck so at least we can get up on plane.. after a few 100 yards of being on plane stuck at 3000 rpm.. it suddenly jolted up to full power and ran fine and i thought my problem was fixed.. i shut it down at the spot we were fishing at and then when i went to move i had the same issues.. however when i jog the electronic choke on the start it actually gives it more power and gets up on plane faster.. still doesn't cruise at the right speed/rpm.. i wondering if this isn't a carb issue?

 

[ss von scalliwag]

Re: 89 mariner 115 problems on the water today

Not an expert by any means but from you have just described it sounds like you need to over haul the carbs.
That should do the trick.