Compression Question????

[thehermit]

Yea...Unfortunately

80 psi: note verticle grooves:



Pull piston: note stuck ring and more vert damage


120 psi: Cy; deglazed with hone 90% of vert grooves gone, cross hatch re-established, comp back up to 120, motor is happy again. Thes pix were about 3/4 thru...it looked a bit better when cleaned. I put in a new cly and ring kit. Rod and needle bearings too.





It dosnt make me feel good that I had to perform surgery but like Tim has said these motors are tough and basic and it didnt seem to mind the work. My motor was a nice clean motor that I aquired for cheap money before I gooned it up. I hope to get a few seaons from it still.

[fdheld34]

John and Tim thanks for the valuable advise and pics to go along with it.

Tim...question for you...before I continue with this motor..with my minor mechanical abilities when it comes to outboards

I spoke with my mechanic who came out and again verified compression last night and it came out same.
He said he would buy my motor as is for $1000 and put it towards purchase for a 2001 200 hp Merc carbed motor that he is going to rebuild plus install all new guages and harness, cables and cotrol box for total of $4000 minus $1000 for my motor..so basically a rebulit motor with 1 yr warranty for $3000. He rebulds motors for race boats etc and did some nice work on my carbs on my 1993 merc 135hp on the back of my Seafari. That was the best boat/motor I ever owned!!!! Also said weight would be 80 lbs lighter with Merc!!!

What should I do...?????oohhhh....
He also found out that stator has been dripping black goo and he said it will probably start to arc..and will eventually need to be replaced and reepoxied???!! and we are abe to tilt up motor by hand..so t/t needs attention.Guess my initial purchase of the Johnson for $1800..taught me a valuable lesson...bring a mechanic!!!
tim..let me know your ideas..do I fart around with this Johnson...I just want a reliable motor that I can put on another Seacraft in future!!!!
Thanks
-Fred H

[Bigshrimpin]

Fred - Pull the heads and look first before you jump into anything or better yet pull the head with the mechanic. You know what you are looking for . . . The bolts are cake to remove (15 minutes total) and even if you do the deal with the mechanic . . . he has to yank the heads off. Make your decision then. That motor parted out is worth around $1000, so what can you get for $4000.

If that 2001 Merc 2.5L 200 has o ring (flat looking heads) style heads . . . stay away. If not, it doesn't sounds like a bad deal to me, especially if he'll rig it and provide gauges, remove oil injection, and offer some sort of warranty/support. If he's rebuilding it . . . ask him exactly what he's doing to "rebuild" that motor.
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Hope this helps!

[gofastsandman]

Yea...Unfortunately

80 psi: note verticle grooves:



Pull piston: note stuck ring and more vert damage


120 psi: Cy; deglazed with hone 90% of vert grooves gone, cross hatch re-established, comp back up to 120, motor is happy again. Thes pix were about 3/4 thru...it looked a bit better when cleaned. I put in a new cly and ring kit. Rod and needle bearings too.





It dosnt make me feel good that I had to perform surgery but like Tim has said these motors are tough and basic and it didnt seem to mind the work. My motor was a nice clean motor that I aquired for cheap money before I gooned it up. I hope to get a few seaons from it still.

Now the class has my attention.
When I talked to Art @BRP tech he said that these motors left the factory at spec between 90 and 130 comp. I thought that to be strange. He said that as long as they were even that was proper spec for release.Said they matched the piston/ ring combos. My motor is 87-92 and turns 5200 light Bimini up. Should I be concerned? Anyone local have a scope?

Decarbed 30 hrs ago w/ Engine tuner thru the Schrader and then pony tank Seafoam 3 cycles. `til the forest fire smoke stopped. 930 hrs now."Pros" all say don`t worry, but I am. Always.
Thx,
GFS

[fdheld34]

Thaks Tim..spoke with him 2 minutes ago on phone..not using o ring heads on rebuild..says he stays away from them...doing total teardown and rebuild back up to specs, including carbs..eliminating oil injection..and using block off plate??-- and said will look like came from factory..no extra wires etc for oil injection. He is going to pressure test lower unit and if any problems will also go through that as well. Also gauges hooked up and quicksilver binnacle control mount.(said he will not charge for rigging)
He is also going to pull head off for me on johnson and give me his opinion before this whole deal takes place. will repost next monday...gotta go to MS for thanksgiving..hate going out there..havent seen father in over 2 years and he always looks older every time I see him ...and he tells me I look fatter!!!!
I will start new thread regarding this due to only 2 thread at a time on this topic....just remember this is on a Mako ...hopefully not for long!!!
Tim....GUESS $4000 could buy me "BIG RED"

Sandy....still have your gps ...your outriggers look tempting.

[Bigshrimpin]

Hey Fred - He sounds like a stand up guy. I'd do 4K delivered with a gallon of flag blue awlcraft 2000 just to make space in my yard.

[thehermit]

Sandy,
Like Fred...my motor was all 120's. I had a lean condition that casued the ring to hang up. After it hung it didnt take long to glaze the walls of the cyl. Tim did coach me up for the repair work which was not bad at all.

Fred...you can have that head off that motor in 20 mins. The lower cowl splits open and you have complete access. This is one thing I have come to like about this motor. Its very easy to work on...but I'd rather be running it [img]/forum/images/graemlins/tongue.gif[/img]

[Bigshrimpin]

Now the class has my attention.
When I talked to Art @BRP tech he said that these motors left the factory at spec between 90 and 130 comp. I thought that to be strange. He said that as long as they were even that was proper spec for release.Said they matched the piston/ ring combos. My motor is 87-92 and turns 5200 light Bimini up. Should I be concerned? Anyone local have a scope?

Decarbed 30 hrs ago w/ Engine tuner thru the Schrader and then pony tank Seafoam 3 cycles. `til the forest fire smoke stopped. 930 hrs now."Pros" all say don`t worry, but I am. Always.
Thx,
GFS

Sandy - your guy is right. I've seen two 1994 200 and a 1995 225 that had 100 - 105 psi in all 6 and perfect cylinder walls. The point were I'd be concerned if you had a motor with 120 psi like hermit's 2000 225 and had one cylinder drop to 80psi from 120. I mess around with merc's so I can't tell you exactly what OMC models were higher compression. If all yours are the same and the motor runs well . . . I wouldn't give this another thought.

[gofastsandman]

Thanks Tim and John. I`ve got the ex 150 low comp version.
There were 5 or 6 versions. the 175 has bigger carbs and I`d imagine more comp. I`m curious now. Bet Corey`s got a scope. Motor runs nicely , even at idle, which from what I`ve read is not really common. Knock Knock.
GFS

[76Red18]

Our 60 degree, or properly named "Eagle Series" motors are lower compression. The one in the pictures appears to be a 90 degree cross flow which can have upwards of 140. The 60 deg 175 has different carbs and porting, not sure on compression numbers. The 60's also use o-rings for head gaskets. If you pull the heads, make sure to apply sealer to the bolts and a thin ring of sealer around the water ports making sure to keep it out of them.