Early 80's 60 hp 'rude low speed miss

[Tuna mad]

Hi all, new to this site, spent an hour or so looking for through this forum for another thread from someone with the same problem, no luck, so apologies if I've missed something somewhere -

Bought a 16 foot half cab about a year ago, with an older (I think early 80's) 60 HP Evinrude twin cylinder, been using it on and off for the last year or so with no problems. Yesterday we took it to a local tuna hotspot and spent about 3 hours trolling at high speed (10-15 knots, at about half throttle), the engine ran so well we actually commented about it to each other about how well the old girl was going (Big mistake!).

We ended up stopping for some bottom bouncing and when we started it up it missed and didn't want to take throttle. It stalled a couple of times and the only way we could get mobile was to run the warm up lever to build up revs, then quickly back it off and slam it into gear and give it full throttle. The engine seemed to be running on 1 cylinder, really sluggish and slow, then the second cylinder would start firing erratically and it would clear itsself then jump up on the plane and take off.

We spent another 2 or 3 hours trolling at around half throttle with no problems, but every time we slowed down or stopped we would have the same problem. I'm having a look at it today to see if I can find a problem, but would prefer to have some basic ideas of where to start. I'll try and get a compression check today and screw a couple of new plugs into it. I'm really hoping someone will pipe up and say "That sounds like classic symptoms of a ......" lol

 

[Tuna mad]

Re: Early 80's 60 hp 'rude low speed miss

Just pulled the plugs out. The bottom cylinder plug has copper color deposits all over it and the top of the piston looks very rough through the plug hole. Unsure whether it's the actual piston that looks rough or whether it's a carbon build-up - Compression test: Top cylinder - 175 psi, bottom cylinder - 125 psi

A late edit: Inside the airbox there is quite a lot of oil, which has actually started running into the engine compartment and down the left side of the leg. At this point in time I am seriously considering trading it in on something a bit newer and better maintained. Something about this motor seems to yell "Bottomless pit!" to me

 

[tashasdaddy]

Re: Early 80's 60 hp 'rude low speed miss

1st model # of the motor. did you check for spark on each cylinder, not mentioned. is this a premixed fuel motor, or an auto mix motor?

 

[Tuna mad]

Re: Early 80's 60 hp 'rude low speed miss

Model is E60TLCRE, it's a 1984 model, running pre-mixed fuel. I took the head off it today, the gasket was leaking. Explains a few things, I thought I'd noticed a bit of steam occasionally. Got a gasket and a thermostat ordered through my local dealer, hopefully they won't be too long getting here (Or too expensive!)

My friend and I (who are both half owners in the boat)have decided to upgrade the boat anyway. Hopefully the new head gasket will make the motor run a bit better and we'll get a better price for it. Thanks for the reply

 

[tashasdaddy]

Re: Early 80's 60 hp 'rude low speed miss

when was the impeller last changed? that leaking head gasket could be a sign it ran hot.

 

[Tuna mad]

Re: Early 80's 60 hp 'rude low speed miss

Impellor was changed about 12 months ago. The old one wasn't too bad, but while it was apart we did it anyway. Looked like the gasket had been leaking a while, there was a bit of corrosion on the head sealing surface too. Getting it welded and re-machined before the new gasket goes on.

I've got a laser heat gun here that I can use to check the running temperature, I'll give it a test on a local fresh water lake and see how it runs before I tow it back to the coast for it's final fishing trip. Then someone else can worry about it! lol

 

[DGLAMBO]

Re: Early 80's 60 hp 'rude low speed miss

please post if the head gasket fixed the problem. im having the exact same issue with my 82 model, i started at the impeller(it was perfect) then have a head gasket being delivered tomorrow, hoping that does it. if it dont i will be on here asking for help.

 

[Tuna mad]

Re: Early 80's 60 hp 'rude low speed miss

please post if the head gasket fixed the problem. im having the exact same issue with my 82 model, i started at the impeller(it was perfect) then have a head gasket being delivered tomorrow, hoping that does it. if it dont i will be on here asking for help.

No worries, will do, should be putting it back together on the weekend. If you do replace the gasket, just have a good look at the machined surface of the head. There was a bit of pitting in mine, around where the gasket was leaking, I'm getting it welded and remachined. My motor runs almost exclusively in salt water, which doesn't help!

 

[tashasdaddy]

Re: Early 80's 60 hp 'rude low speed miss

you could also have a clogged low speed jet, when were the carbs last rebuilt with a kit? you have 3 jets in those carbs. http://shop2.evinrude.com/ext/index.aspx?s1=bf6ad09c53cead335fcfd8a6471c0f7f

 

[DGLAMBO]

Re: Early 80's 60 hp 'rude low speed miss

All of my problems started with it overheating once. i immediatly shut her down and got back with my trolling motor. I knew i was going to have to replace the head gasket because of oil seeping out and running down the sides, however i figured that was just the effect of getting hot. i took it off and it was blown completly out and the thermostat looked horrible.
Im with you probably put it back together this weekend.

I dont know if the carbs have been rebuilt. had it 3 years and i havent done it i know, but i do have the kit in the garage.

 

[Tuna mad]

Re: Early 80's 60 hp 'rude low speed miss

The courier that was supposed to be delivering my parts picked them up from the shop, but for some reason didn't get them to me

Won't get the bits till next week now, so that will put me back a full week. Not happy

 

[DGLAMBO]

Re: Early 80's 60 hp 'rude low speed miss

i just got back from the lake, she purs like a kitten. not any problems anymore.