Johnson 150 Rebuild/Remanufacture Guidance

[Terrapin]

I need some rebuild/remanufacture guidance for a 1986 Johnson 150 HP crossflow engine I own. The model number is J150TXCDC. I have owned this boat (1986 Boston Whaler Outrage) and motor set up since 2003. The engine has over 1,200 known hours on it. It has one slightly scored cylinder (scored prior to my purchase), and I no longer get 5500 RPM out of the engine, but it runs ok at top end (4900 RPM). I have maintained the engine well over the years. In addition to standard maintenance such as carburetor rebuild, water pump replacement, and decarbing the engine, I have replaced the VRO. The furthest I have been into the engine is cylinder head removal to replace the water deflector tubing which were constricting proper coolant water flow. The cylinders were never over bored and are at 3.500 inch diameter. Currently, the engine seems to be smoking more than typical (rings?) and upon shutoff I get oil and fuel leakage down the midsection (powerhead gasket).

The question I have is whether there is a reputable shop someone can recommend to either rebuild my powerhead or a reliable option for a remanufactured powerhead? I found Blackbird Motors in my search, but I also uncovered many negative comments on them. Secondly, I looked into TMS Marine in Cookson, Oklahoma, but apparently they no longer rebuild Johnson crossflow powerheads. Are the crossflows a problem for parts or something? Let me know if there are any reputable and reliable options available.

Lastly, is this something I can take on myself with my Johnson Shop Manual as a fairly decent shade tree mechanic with my torque wrenches, or will I end up needing specialty tools that makes the cost of the project spin out of control? I did uncover some pretty good rebuild videos for a 150 Johnson on the Dangar Marine YouTube site.

In closing, I am a bit reluctant to invest in a new motor and the related changes needed for controls and gauges for this old boat. I actually like the classic feel of the analog gauges etc., and this motor seems to be bullet proof. Albeit, it is a gas guzzler. Sorry for the long winded post, in short I am looking for guidance/suggestions.

 

[racerone]

Rings have noting to do with the smoking.----I recommend you take it apart.----Measure and inspect everything.----All new gasket set and crankshaft seals.----Inspect all crankshaft seal rings.------And 6 new 0.020 O/S Wiseco pistons.----Don't forget to make sure lower unit is inspected and resealed at the same time.

 

[ct1762@gmail.com]

nothing as far as specialty tools, accept a good micrometer and bore gauge. might get lucky and it will clean up with just a hone job at home and one new piston.

 

[Terrapin]

If I decide to tear into this myself, is there a rebuild kit supplier you would recommend purchasing from for quality parts/components? Possibly a supplier that would be willing to answer occasional questions along the way?
Can you suggest a shop that focuses on outboard powerhead machining? I am in the Maryland/Pennsylvania area, but willing to ship to any reputable machine shop.
Thanks for the replies.

 

[ct1762@gmail.com]

If I decide to tear into this myself, is there a rebuild kit supplier you would recommend purchasing from for quality parts/components? Possibly a supplier that would be willing to answer occasional questions along the way?
Can you suggest a shop that focuses on outboard powerhead machining? I am in the Maryland/Pennsylvania area, but willing to ship to any reputable machine shop.
Thanks for the replies.

i'd go with Bill from mastertech marine. maxrules.com . order by phone he will give you a discount over his ebay store.as for a machine shop, i'm from CT/RI area so don't know of any down your way. i do know Carson's marine in Florida does great work, but he did quote me a higher price for just machine work as they do full rebuilds mostly.

 

[Faztbullet]

Call Jason as he did the boring at MarFab. Quick turn around and I suggest WSM piston kits....and Jason can supply all. Can even short block it for ya!!
One stop shopping!!!
Jason White at
Jay’s Block Shop in Tennessee
Contact info: Jay’s Block Shop
3015 McMinnville Hwy
Sparta,Tn. 38583

(931) 808-0814

 

[ct1762@gmail.com]

Good info right there. I might send my v4 project block there next.

 

[Terrapin]

Thanks for the help with the rebuild shop names (Carson's Marine and Jay's Block Shop). Let me know if there are any other reliable rebuild shops out there, or additional comments for these two shops. Faztbullet mentioned Jason can short block it for me. Is that a complete rebuild of my undressed powerhead?
Is there a reason why shops like TMS Marine in Cookson, Oklahoma will no longer rebuild Johnson crossflow powerheads?
Will each of these rebuild shops use their preferred piston manufacturer? I didn't give this much thought, but OEM pistons and related components seem to be priced very high and out of my budget. I was leaning toward Wiseco and never heard of WSM Pistons.
Regarding rebuild kits, I will check out the maxrules site. However, the website seems to be down today.

 

[Faztbullet]

WSM supplys 80% of the aftermarket piston kits you see for sale ,other just people box them under their brand. Vertex and Wiseco are the others. The WSM's are as close to OEM but better. Call Jason and tell him Alan said call. He will give you straight up no BS answers

 

[ct1762@gmail.com]

i just talked to Jason. i'm doing a v4 gt-100 as mentioned and he said Vertex are the best money can buy. He will bore my block depending on which pistons I choose. Vertex are rare for the crossflows. Wiseco obviously need more room to grow in the bore. he knows his stuff super nice guy and extremely reasonable prices. Thanks Fazt!

 

[Terrapin]

Thanks for all the comments. I am reaching out to a few of the individuals mentioned for additional information. Of course, I have more to learn about which piston to go with. Wiseco (forged) or WSM (cast), and now Vertex (cast). Jason at Jays Block Shop seems very nice and knowledgeable.
Lectro88, I believe the days of $8.00 a hole are gone. We are looking at $50 - $60 it seems.

 

[Faztbullet]

Jason was the one that did all the machine work at MarFab before they closed and if I remember correctly a BRP Master technician.

 

[Terrapin]

i just talked to Jason. i'm doing a v4 gt-100 as mentioned and he said Vertex are the best money can buy. He will bore my block depending on which pistons I choose. Vertex are rare for the crossflows. Wiseco obviously need more room to grow in the bore. he knows his stuff super nice guy and extremely reasonable prices. Thanks Fazt!

ct1762, You mentioned that you are going with Vertex pistons. What does your comment, "Vertex are rare for crossflows" mean? Does it mean that Vertex does not cast pistons for crossflows? Possibly due to the piston top/dome ?

 

[ct1762@gmail.com]

ct1762, You mentioned that you are going with Vertex pistons. What does your comment, "Vertex are rare for crossflows" mean? Does it mean that Vertex does not cast pistons for crossflows? Possibly due to the piston top/dome ?

Good question! After I wrote that, I checked ebay and there seems to be alot of them available. Which is great news. I didn't realize they were around. Jason just seemed to think they were hard to find I guess.

 

[Faztbullet]

They are sometimes difficult to get thru the dealer network..Jason and I dont buy off Sleazbay

 

[wayno01]

I wouldn't buy pistons from eBay. I ordered what was supposed to be six .20 over Weisco pistons a few months ago and received a no name set that were .30 over and looked used and it took forever to get them. They were cheap but unusable. You could get lucky and receive what you order if you want to take the chance.

 

[ct1762@gmail.com]

I wouldn't buy pistons from eBay. I ordered what was supposed to be six .20 over Weisco pistons a few months ago and received a no name set that were .30 over and looked used and it took forever to get them. They were cheap but unusable. You could get lucky and receive what you order if you want to take the chance.

very true. i just got word from my OMC guru that said he called Vertex and those crossflow pistons are indeed NLA. Your right... im sure i would've gotten an off-brand. Pro Marine will be the ones i use.

 

[Faztbullet]

"" I am electing to avoid the crossflow/high dome pistons ""
You mean high ring pistons but those hasn't been offered in many years..

 

[ct1762@gmail.com]

Now i'm confused... it's a crossflow so needs domes. how else would it run without the deflected dome?

 

[Faztbullet]

Lectro88...They do not make high dome pistons for OMC..that is a Merc crossflow thing. To change compression on OMC you use tighter heads. Also aluminum will not "glow". All the pistons are the same in a 150-235 crossflow..only difference is the porting, heads,CC's and carbs to get different HP's. You need to be very careful with your 175 as it has thin cylinder liners to begin with. The cooling system has to be top notch for it to stay together and running at low/mid RPM for extended time is worse than running WOT due to the fact you are running full timing and lean A/F ratio. This is where most pre-ignition occurs