1983 Evinrude 115hp idle.....watch video

[ashedd]

I've put a lot of work into this motor. It came on a project boat I have, hadn't been run in god knows how long. I decided to put it into service on a boat I got with questionable merc 500's. I was going to put it in the water for the first time today, but after doing my final engine checks I decided it wasn't running quite right. I took the carbs off a few weeks ago and soaked them in a can of carb cleaner, removed the bowls, then I sprayed brake cleaner into everything I could see, followed by canned air. I didn't remove the four screws that apparently cover some jets or something. Seems a tad hard to start when cold. Watch the vid and tell me what to fix, I'm sick of working on this motor and I want to use it. Thanks

 

[interalian]

Sounds not bad for muffs. They tend to pop and sputter somewhat without backpressure.

 

[ashedd]

Really? I had it had high idle once and it was popping and putting out a big puff of smoke with the pop. I don't have a container big enough to dunk it in... Maybe I'll just put it in the water and see how it does. Problem is the boat launch and my moorage is about 4 miles apart, so If it dies while underway I'm screwed. I got the kicker running good but it still gets pretty hot after I did the impeller, cleaned cylinder head and exhaust plate of corrosion. Never did steam after an hour running, last year it would steam when it got too hot.

 

[emdsapmgr]

The engine sounds pretty normal for running on muffs. I note that the engine does not shake at all, rather unusual for a 2-stroke 90. Running that smoothly makes me wonder if it's actually firing on all 4 clys. On those engines, it's realty hard to tell just how many cyls are firing.It could be only firing on 3 cyls, and it would be hard for you to tell by listening to it. Check for fire on all 4 cyls. If it's firing on all 4, you should be good to go...

 

[ashedd]

The engine sounds pretty normal for running on muffs. I note that the engine does not shake at all, rather unusual for a 2-stroke 90. Running that smoothly makes me wonder if it's actually firing on all 4 clys. On those engines, it's realty hard to tell just how many cyls are firing.It could be only firing on 3 cyls, and it would be hard for you to tell by listening to it. Check for fire on all 4 cyls. If it's firing on all 4, you should be good to go...

I thought about that and unplugged each spark plug and it ran more rough each time. I also switched the wires around on each side and it barely ran at all, so the coils are on the right cylinders. There's just one little cooling issue I need to work out today, then I'll put it in the water. I'm also going to replace the plugs on both motors, I suspect the kickers has the wrong plugs in it, maybe even hotter ones.

 

[emdsapmgr]

Your cylinder "drop" test you performed came out perfect. All cyls are contributing to running the engine. Lucky to have such a smooth running crossflow. Am wondering if it's a really low hours powerhead? (not that you can tell on that engine.)

 

[oldboat1]

Saw your thread on the 20' Tollycraft. Happens I ran a '70s 85 on a 20' Trojan Sea Breeze cruiser ('54) for a number of years. Performance was fine. It was a mistake only in that I should have been running period motors.

I did have an issue with the built in tanks on the Trojan, and ran bad gas at one occasion. Recommend running fresh gas with a portable tank while testing out the Evinrude. It sounds ready to go.

Got a thread on the trolling motor? Sounds like a nice rig in the making.

 

[ashedd]

I found an old cooler at the boat yard and got as much as the LU in the water as I could(see vid). It did make the motor harder to start though... I'm also having a really bizarre cooling issue, I'll start another thread on that one. I haven't started a thread on the kicker, I think the only thing else I can try with it is to clear out/replace the grommet at the top of the water tube. I have no idea the hours on this 115 evinrude, all I know is the motor sat for a long time outside on an 18' Thompson that I bought and later got rid of. I have another 18' Thompson that I'm slowly working on. I was looking for another motor for this Tollycraft awhile back, but I've got so much time invested in this evinrude that I decided to keep working on it. I think I figured out that 70 hp wasn't enough but that 90 would be ok. I only found old merc's around 90 hp at the time.. and I'm still not too sure about mercury's. I'll be running off external tanks while in the testing phase.. I have no idea what size internal tank I have now. I know it's steel, original, and uses solid copper fuel line. Previous owner said he never filled it completely or ran it all the way out, so he didn't know what size it was. It doesn't have a fuel sender, which I don't care for, I would need to add one. Definitely will add a water/fuel separating filter first though.

https://youtu.be/oXQc0rc4RwA

 

[ashedd]

UPDATE: Boats in the water and the motors been doing well. The hard start when submerged issue I was having is gone, fires right up. You just have to bump the primer a few times until it smooths out. I found what I suspect to be an intermittent power pack and replaced it with a used one from my boat yard neighbor. Seems to be doing well. I need to get a tach hooked up so I can see the WOT revs, sounds like it might not be making 5500 rpm, but my 20' wood cabin cruiser was doing 27 knots in rough water and wind.. But it sure did suck down some gas. I had 2/3's of a 6 gallon tank and after 15-20 mins of WOT I had maybe a gallon left, had to switch to the backup tank. Smoke is basically non existent compared to the 175hp blackmax on my last boat. I've been using the quicksilver synthetic blend 2 cycle oil that I had for the merc. Trying to make up my mind on a full synthetic oil I want to use, and also what ratio. The motor is also charging the batts, which I'm happy about. Now I just need to decide if I'm going to swap the LU out for one that is fully sealed up, and how I'm going to do that on the water.