Best Engine Rebuilder for older Johnson GT 150

I am doing a lot more saltwater fishing right now due to the heat so boat is just sitting under the cover and I am looking for a good referral ( preferbally 150 miles from houston or closer) for a rebuilder. I cant afford a new one and she struggles to do 45 now and when I got her she would push upper 50s. I had a head gasket job on it after an overheat and guy told me I hurt it a little but it still runs good enough for me, just thinking she could run much better with some better guts. No idea what to look to pay so that might help also if others had similar experience. I am told Stone and Sons here locally is good but have no experience with them. Also what kind of issues come up that cost more than what they quote sometimes if you get my drift.

Personally, I would buy a OEM service manual. Service the carbs, plugs, and go over the timing. You would be surprised what you can do with a manual & youtube. IF your not the tinkering type, you will prob get a good recommendation. Most marine dealers/service are a month out getting in line for work. At least that's the way I see it in DFW area. If there is any of that oil injection equipment, and you can get rid of it and goto mix only I would get rid of the oil injection. I also am running a old motor, but have done this and it is running good. I still baby her, not wanting to re-power just yet. Good luck

Gary at Hughes Marine 214-797-0373 tell him Denny sent ya.

Do a compression test. If all are 80 plus and within 10 percent of each other, you've got other issues.

This ^^^^^^, Plus thats an older engine. Is it carbed? If it is, that’s a more simplistic job that just about any marine place should be able to handle no problem.

80
90
90 port side

80
75
90 starboard

I just got back from the lake and its still warm. It ran 42 this morning pretty much wide open. I got it 10 years ago and it was upper 50s, sometimes 60/

Carbed, 3 of them stacked as a matter of fact. Fuel filter clear. fresh gas. Little hard to start early but after that it cranks with just a touch to the key. I would think this thing should be making 100 on all cyllinders if healthy. Was going to post on BBC but ill get guys telling me to go all over US.

Seems to me that #5 (75 PSI) may be struggling, I would take it in too.

I agree with frank, 5 is not healthy.

you could try a decarb first and see if that loosens things up, may just have a ring or 2 sticking some.

youtube for decarb process, pretty simple but don't do it over concrete while on the muffs, the stain will not come out.


I use seafoam, some use ring free both are good for decarb.

I did a can of engine tuner years ago, worked great the first time, second time she went in for all 3 carbs to be rebuilt, it never ran right until after that was done. Like 16 a can too. I am looking into some options this week.

I know Mike’s Marine (281) 998-2219 in Pasadena does great work. I haven’t needed him in a while so I’m not sure if that’s still the right number. He’s on Beltway 8. Been using him for over 30 years. I had a GT 150 on one of my previous boats and he had it purring like a kitten whenever I had issues. He has never “screwed” me either when he could have easily. The only issue I ever had, he is so busy that he seems to always be very backed up. I do agree you may issues with that one cylinder. Good Luck

Try talking to Holiday marine in Huffman, heard they do good work.

You won't find anyone more knowledgeable than Joe and Jack at Stone and Son. They are not the cheapest around, but do good work and are open to discuss options. Had them rebuild an old 115 and it runs like a top.

Try Bowden Marine at 3000 Atascocita Rd, Humble, TX 77396, (281) 441-7773. Ask for Steve Wright, he cut his teeth on the old Evinrude/Johnson motors. I have used him -- he is honest

Evinrude engine tuner. Pull the plugs. Fill each cylinder,. Let them soak overnight. Take to the lake, run another can through carbs while running. Run wide open throttle for 10 to 15 minutes or until white smokes clears, then recheck compression.