78 18hp evinrude powerhead question

[Rwed]

Well. My good luck steak is over. This one... Flywheel will not turn. So is this my first seized up motor? Id like to get it to run off i can. What are my first steps? As always. Your help is very much appreciated.

 

[Crosbyman]

step 1 .... scribe the flywheel somewhere to establish a referrence point… keep watching for small mouvements​

step 1a ..... drop the lu make certain the blockage is not in the gearcase

​

step2.... squirt some deep creep, atf oil, kerosene, loose nut, PB blaster whatever…. in the cylinders and soak for a few days then try jarring the flywheel .. if nothing happens step 3

step3 …. pull the cyl head resoak the pistons a few days then take a wood peg (about 1 inch) start hitting the cyl with the peg and blow hammer cautiously and by alternating

step 4... if nothing moves resoak a few days and try peg/hammer with persuasive blows but not to persuasive

keep at it till you give up. I didn't and ended up with this a nice 9622a for 50$

 

[racerone]

What is the model # of this 78 motor that is 18 HP.----Does the flywheel turn a little bit or is it absolutely stuck.----A little bit of movement means pistons / rings are stuck in the bore.----If flywheel has zero movement than it may be a bearing issue.-----Remove bypass covers to have a look at pistons.

 

[Rwed]

I think it ran until it quit. Short video i saw. Has it sputter to start then die right away few times. But i thought i heard knocking while it tried to run. What would it take to get a diagnosis? I'll try taking lu off. But it goes in and out of gears. I feel the issue is in ph. But like i Never been inside one

 

[Rwed]

racerone: correction, i looked up, it's 1968 evinrude. So, flywheel doesn't even budge a little. I was waiting on my first powerhead problem. So, my next question, can i get it repaired wo breaking the bank? what would be my next steps? TIA

 

[racerone]

There were lots of these motors made.----Lots of good used parts available and cheap.-----Crankshaft was the same from 58 to 76 models-------Some will argue.----I say take it apart for evaluation.

 

[oldboat1]

I think it ran until it quit. Short video i saw. Has it sputter to start then die right away few times. But i thought i heard knocking while it tried to run. What would it take to get a diagnosis? I'll try taking lu off. But it goes in and out of gears. I feel the issue is in ph. But like i Never been inside one

Unique if you got a video of it in its death throes. Did it overheat and seize up? Look for scorching.

 

[Rwed]

maybe i ask him. i doubt he is willing.maybe u r right.

 

[jimmbo]

If the powerhead is still locked up after dropping the lower unit. Pull the bypass covers to inspect the rings/piston skirt, and the head to check for signs of broken rings
Racer is correct about there being plenty of used parts, including compete power heads, lower units, complete outboards

 

[Rwed]

well, that little prick won't even send me the video... oh well. So, it looks like i'll try rebuilding it myself. do i need specialty tools for this project? also, any idea on the cost in parts? I'll be doing all the labor

 

[racerone]

Cost of parts depends on your area , ability to shop and patience.-----I have picked up parts motors for next to nothing ( even free ) hoping for good internal parts.----You demand good parts at your front door in 3 days you have to pay.----No special tools required.

 

[Chinewalker]

Basic tools - wrenches and screwdrivers - will handle most of what you'll need. A 3-point harmonic balancer puller and three grade-8 1/4-20 bolts will handle the flywheel. That's about the only special tool I can think of off hand.

 

[oldboat1]

torque wrenches, maybe -- inch lbs and foot lbs. I've done a lot of repairs without them, and have sometimes regretted it (think flywheel nut torque). You might be able to borrow or rent them from an auto parts store when you need them.