Is it worth fixing? - 1979 200949A 150 HP Evinrude

[MarvinGabriel]

OK, so I removed the heads last night, and found the issue that killed the motor. One of the pistons is all tore up! Apparently, something came loose and bounced around inside the cylinder. I suspect a broken ring, (maybe caught on the exhaust port) but haven't had time to remove the powerhead, and tear it down yet. The thing is, the cylinder walls have no ridge at all, don't have any scoring or scuffing (other than the cylinder with the busted up piston.) It also has no vertical play in any of the pistons. I've got experience rebuilding automotive engines (I used to work for a dirt track racing team, and have rebuilt my share of small block chevy engines, and pinto engines. The engine seems, so far, to need to be bored, or re-sleeved, some new pistons/rings and that's about it. At the end of the rebuild, it would still be a 1979 Evinrude, and I can't imagine the parts will be easy to find. Heck, even a partially blown newer motor may be a better deal. I'd still like to hear opinions as to the longer term maintainability of an engine like this.

Thanks!

 

[havoc_squad]

That motor, I would probably consider that one to be used as a boat anchor or scrap metal and not worth the money to rebuild.

If you get a 150 HP/175 HP motor from 1980 to 1991, you might be able to re-use your lower unit if it is still in good condition. (subject to verifying compatibility first.)

I recommend to get an OMC Johnson/Evnirude looper or crossflow carbed motor that uses the primer solenoid and not a choke. Those you still can get parts for. Your choke solenoid is NLA on that motor and a lot of other components as well.

Avoid anything labeled FICHT like the plague. When you go into fuel injection territory, be prepared to pay up a lot for fuel delivery replacement parts.

I believe for most 85 HP to 150hp motors from 1980 on up to the late 1990's fall in that category, though many of the 1990's 60 degree loopers have the Vapor separator tanks which adds a layer of complication. I don't know a lot on those 60 degree looper motors, so I can't comment on how problematic they are regarding the fuel system with that VST tank.

Bypassing the VRO system to do pre-mix on these motors is fairly easy, but you have to make sure you get the right fuel pump to avoid starving certain motors of fuel.

The 85 to 115 HP 90degree V4 crossflow motors from 1979 to 1998 use the same lower unit mating system. However, there are two different splines used. 1979 to 1991 is the old spline version. 1992 to 1998 is the new spline.

The V6 OMC motors are a little bit more confusing on compatibility. However I believe this also has an old gen shaft and a new gen shaft variation (1979 to 1991 old gen shaft, 1992 to ??? for new gen shaft)

With the newer lower units that allow changing out the drive shaft without complete disassembly of the lower unit, you can order the new or old gen splines to match the powerhead's splines.

 

[oldboat1]

Spring is not the best time to buy, price-wise. Not a bad idea to keep the current motor for parts, if you have the room. But I would find the best motor for the money, regardless of parts you might have "on hand". I was warned some years ago about '80s motors, but don't know if that's true, and wouldn't apply to the whole line anyway. Do a compression test on anything you are thinking of buying.

 

[jimmbo]

It depends on how much it is going to cost to Rebuild that Engine. Once the Powerhead is Restored, then you have the Rest of the Engine to worry about. Say you spend 2 Grand rebuilding it, and next year the Gearcase implodes... Since you already have a bunch invested this motor, you either throw the money away or continuing spending whatever it takes to keep it running. It might be a Fine Engine in the end, but you will not get any of that money back if you try to sell it, as it is a 41 yr old Motor that was Maintained.
Feed it a Good Oil at 50:1. XD-50 or Mercury's Premium 2 Stroke Oil, are Two of the Best.(that ought to start an Oil War).
I like the 150 from that Era, Lots of Torque(50% more Displacement than the V4 140hp)

 

[racerone]

I would not hesitate to rebuild that.-----Take lower unit apart for inspection / reseal now.----In my opinion parts availability is NOT a problem.----For example if the choke solenoid failed you would simply install a newer primer valve to get near instant starting !!

 

[MarvinGabriel]

Yeah. I suppose I need to crack that powerhead and see what the extent of the damage is, before I make any decisions. The lower unit looks good, and had clean oil in it. I'll pull that today,and assess the condition. It'll take a little longer to get the powerhead assessed, since this is just a long term project boat.

 

[havoc_squad]

I would not hesitate to rebuild that.-----Take lower unit apart for inspection / reseal now.----In my opinion parts availability is NOT a problem.----For example if the choke solenoid failed you would simply install a newer primer valve to get near instant starting !!

Wouldn't that require sourcing compatible carbs that have that inlet or would that be drilling and tapping an inlet barb on the carb for a primer solenoid fuel line?

I probably should have said parts availability for certain things such as the choke solenoid might be a critical issue and I don't have the data on a suitable work around for that problem.

If there was not a solution/work around, then I would say that motor would not be a good choice to rebuild.

 

[racerone]

Installing the OMC primer should be easy I would think if you understand the concept of this primer valve..-----It is used on 9.9 HP to 300 HP motors.----Works great.----Can be installed on MERCURY motors too.

 

[havoc_squad]

Looks like someone has already done this and added pictures of it on iBoats forum adding primer solenoid fuel hose barb on the carb.

https://forums.iboats.com/forum/eng...rds/10152011-retrofit-82-primer-from-79-choke