112 SPL has rough mid range running. Otherwise runs good. Opinions?

[JLesko]

I have a 1996 Evinrude 112 SPL. When running, the engine idles fine below 1000 rpm and purrs like a kitten above 4000 rpm all the up to WOT. Between 1200 - 3800 rpm, it runs and makes power, but is definitely running rough. Still usable to go out and have a good time on the water.... There is a 14 x 13 pitch prop on it (when I got it it had a 13.75 x 17 and would not get over 4300 rpm's and took forever to plane) and the boat is a 1996 Wellcraft 190 CCF. I tried the Seafoam cleaning method, good fuel, good fuel filter. Could this be a dirty carb / plugged up jet issue or a bad ignition coil? What are your thoughts on this. Thanks!

 

[racerone]

Well if there is a plugged jet in the carburetor you would be starving that cylinder of fuel.-----AND OIL !------So stop running it and do a compression test.----Post your numbers.

 

[JLesko]

Will do.

 

[JLesko]

Checked compression today... Ran the for about 20 minutes first to get it at normal temperature. All 4 cylinders are between 110- 115 psi on the gauge.

 

[racerone]

Do you have spark on each lead that jumps a gap of 7/16" or more, yes or no ?----Perhaps test run with another tank and hose.-------Test run with cowling off.

 

[JLesko]

The spark is good and it runs the same on a pony tank with different gas.

 

[racerone]

Good luck with the repairs.-----More trouble shooting is required.-----When you go to a 13" pitch the RPM will go up but I think that pitch is too low for that boat!!.----My guess is that there are issues with this motor.-----Have it tested on a dynamometer or with a test prop.-----Cleaning the carburetor would be a good idea.-----Check diaphragm in fuel pump.-----I think there is an easy fix for this motor !

 

[JLesko]

The pitch is kind of a compromise to keep it on plane with 4 people, fuel, boat weight, etc. I thought about going with a 15 pitch, but if it doesn’t help I wasted $140.00 on a prop... I rarely go over 22 mph anyways because the kids don’t like going fast... In reality, the 112 is a tad too small for that boat. A 135 would probably be perfect... But, I got the boat for $5200, so it will make due for going out on the weekends in the Severn river outside of Annapolis. I will take it to a mechanic this weekend and post what fixes it for others to see. Thanks!

 

[spybot]

Hey JLesko no offence to your mechanic But !! You were speaking to one of the most Knowledgeable people in your country on these motors if he cant steer you down the problem or gives you any pointers I would take these as Gospel.
Just me 2 cents worth and I dont even stay in the US

 

[jakedaawg]

I am just going to chime in on the propping comment...

Many folks on here imply that they need to buy a prop and if it's wrong they are stuck with it...I am assuming they are shopping online for the best price.

Around me there are 3 prop shops. They will all let anyone try a prop for pitching purposes as long as they know you will buy the eventual selection from them. Try a prop, return it undamaged and get another, buy the right one.

It pays to develop relationships with your local businesses in some cases.

 

[JLesko]

No offense taken! I am just at a point where it is something I just don’t have the time to do myself. I was just looking for ideas to rule out something simple. I hate spending money on something I can fix myself. I am gone 2 weeks per month on travel for my job and when I am here I just want to be on the water with the kids. I asked around Annapolis for shops
( there are not many outboard shops) that will let you try different pitches before you buy, but didn’t really find any... It is kind of a time vs. money thing for me... The problem with working so much, is you make more money, but have to spend it fixing stuff you don’t have the time to fix!

 

[racerone]

Many simple things can be checked at no cost to you.--------Also consider that the boat could be waterlogged.----Best is to determine whether motor is producing the ACTUAL POWER that the decal says it has !!!

 

[oldboat1]

You might drive over to Fairwinds Marina on the Magothy (at Deep Creek). The ownership has changed, but check out the shop -- had a good reputation for repairs. Good option if you are stretched for time, although I'm sure the shop is going to be pretty busy right now.

 

[JLesko]

I have been going to Fairwinds for years. They are a pretty good shop, they just have a long wait during the summer ( which is to be expected ). Went out today for a few hours and runs like a champ at 5000 rpm / 22 mph. I could probably let it go and just use it until fall like it is, but it will just nag at me everytime I go out ...

 

[jimmbo]

That motor should be able to spin a 17 at about 5000 on that hull, not counting a fouled/distorted hull. If it is starving for fuel on one or more cylinders, propping it to spin within the WOT range, in fact running it period is performing an Execution

 

[racerone]

+ 3 on the above comment.-----I suspect there is something wrong with the motor.-----Dropping the pitch to get more RPM is not a FIX.-------" execution " is a new description for running a motor to death----I like it.

 

[JLesko]

I will post what they find and let you guys know. Thanks for the replies!

 

[JLesko]

So..... I took the boat to the Evinrude dealer. They checked the spark, carbs, cylinder pressure, the plugs having an even about of discoloration, etc. The only thing they found was throttle rollers are cracked and they said that could cause the timing to be off. They are changing those. The guy said that the “ rough” running in a specific rpm range may be just be a characteristic of a cranky 22 year old 2 stroke engine, since they can’t find anything else wrong... They did find water in the lower unit gear case, even though I changed the oil a few weeks ago. No surprise there, even though I was hoping changing the o rings in the plugs (the top plug had no o ring and when I changed the oil a few weeks ago for the first time, white goop oozed out ) when I changed the lower unit oil would fix it. They think it is a shaft seal. He said that is the typical culprit. The new seal plus a new impeller is 450. Might as well do it, since I plan on keeping the boat for 4 or 5 years. Total for all repairs is right at 800. I have a total of $6600 into the boat after buying it for 5400..... I guess getting on the water for 6600 is not too bad for my first starter boat... Thanks for all the replies!

 

[jimmbo]

The guy said that the “ rough” running in a specific rpm range may be just be a characteristic of a cranky 22 year old 2 stroke engine, since they can’t find anything else wrong...

Hmm... couldn't find, or didn't look at all possible causes

See how it runs, they may have corrected it with replacing the cam follower, it will affect the Pickup Timing as it changes the Snyc between the Carb and Timing Advance and less than smooth performance can happen

 

[JLesko]

It should be done tomorrow. I will post on here it that fixed it or not .