Looking for a winter project.

[Chas0218]

Well I have the old 235 seahorse that was on my boat when I bought it and thought I would get it running again as a winter project. The previous owner pulled the powerhead and said it needed new exhaust tubes. I haven't dug into it yet but I figured I would first check compression. Motor hasn't been run in 4 years so I figured some oil in the spark plug hole and throw a battery on the starter and try to turn her over, worth a try? Also how would this motor compare power wise to the 1991 150hp johnson currently on our boat? I mean if this 235 has good compression and the exhaust is repairable I would think that 235 would push my boat better than the 150. I am currently using the prop off the 235 on my 150 and the motor pulls 5200 at 31mph. I would like to get a little more speed out of the boat but right now it could pull a house.


Few specs on the boat:
~4000 lbs. with gear and people
23' Pro Line w/a


Thanks,
Chas

 

[dehydrated]

Re: Looking for a winter project.

The 235 is a good powerfull motor if done right ,weight wise pretty close give or take a few pounds . Power wise depends what you do with it and didnt see what year the 235 is

 

[emdsapmgr]

Re: Looking for a winter project.

The 235 engines were solid engines at the time. Lots of hp and power. Lousy fuel economy. You did not mention the year and it makes a difference. The early 235 engines (1978/79) were the same cubes as a 150/175. Some time after 1980 or 81 the factory bored them to 2.6 liters. These early crossflows were crankshaft hp rated. After around 1985 or 86, the engines became propshaft rated, so these early engines do not make as much real hp as the later ones. They all weigh between 390 and 410 lbs, so the weigh makes little difference. In your case, your 150 hp engine will compare to around 220-225 for the 235. That's a huge difference and will give you the speed increase you are looking for. These early 235 crossflows had high ring pistons and ran great on the old leaded fuel. These piston/ring combinations were sensitive to today's (ethanol blend) fuel, so make sure the compression is ok before you buy. The controls are the same, so it's a plug and play type of swap.

 

[metriccrescentwrench]

Re: Looking for a winter project.

....I am currently using the prop off the 235 on my 150 and the motor pulls 5200 at 31mph.....

5200 at WOT seems kind of low, that engine will be happier if you go to a lower pitched prop. Shoot for the top of the recommended rpm range with a light to medium load. You might just gain a couple mph with that change because your engine probably isn't putting out it's max rated HP at 5200 rpm.

 

[Chas0218]

Re: Looking for a winter project.

The 235 engines were solid engines at the time. Lots of hp and power. Lousy fuel economy. You did not mention the year and it makes a difference. The early 235 engines (1978/79) were the same cubes as a 150/175. Some time after 1980 or 81 the factory bored them to 2.6 liters. These early crossflows were crankshaft hp rated. After around 1985 or 86, the engines became propshaft rated, so these early engines do not make as much real hp as the later ones. They all weigh between 390 and 410 lbs, so the weigh makes little difference. In your case, your 150 hp engine will compare to around 220-225 for the 235. That's a huge difference and will give you the speed increase you are looking for. These early 235 crossflows had high ring pistons and ran great on the old leaded fuel. These piston/ring combinations were sensitive to today's (ethanol blend) fuel, so make sure the compression is ok before you buy. The controls are the same, so it's a plug and play type of swap.

I am not sure about the year quite yet. I bought my boat with this motor but haven't looked into the year of the motor, I can't remember exactly but I think its a early 80's. I'm not afraid to dig into the motor and mod it a little to get some added hp.

5200 at WOT seems kind of low, that engine will be happier if you go to a lower pitched prop. Shoot for the top of the recommended rpm range with a light to medium load. You might just gain a couple mph with that change because your engine probably isn't putting out it's max rated HP at 5200 rpm.

5000-5500 is the power range for the motor so i figured 5200 was good.

 

[emdsapmgr]

Re: Looking for a winter project.

At 5200 rpm full throttle you are lugging that engine. The 200 and 235 engines are high port engines and have higher factory rpm operating ranges than the 150 and 175 of that year. The factory rating is between 5250 and 5750. You want to rev that engine to at least 5750 with the right prop. Your accelleration and fuel economy will improve if you turn more rpm's. It will make solid hp up to 6000 stock from the factory. At 5200 rpm's you have too much pitch on the prop.

 

[Chas0218]

Re: Looking for a winter project.

At 5200 rpm full throttle you are lugging that engine. The 200 and 235 engines are high port engines and have higher factory rpm operating ranges than the 150 and 175 of that year. The factory rating is between 5250 and 5750. You want to rev that engine to at least 5750 with the right prop. Your accelleration and fuel economy will improve if you turn more rpm's. It will make solid hp up to 6000 stock from the factory. At 5200 rpm's you have too much pitch on the prop.

Just to make sure are we talking about the 1991 150hp or the 235? haha The prop that is currently on the motor isn't the correct size but I am a little hesitant of dropping $200 on a prop that still might not work. The size is currently 15.5 x 15 I definitely want to stay with the 15.5 diameter because the boat drives much easier with the larger diameter.

I just got on the Michigan Wheel site and they suggest a 15.5x17 prop but if I were to do that my rpm would come way down.

Thanks,
Chas

 

[dehydrated]

Re: Looking for a winter project.

There must be a local prop shop around there .Most of those guys will let you try differant props till you get it right it helps to try more than whats suggested in a manual plus i try to buy local

 

[emdsapmgr]

Re: Looking for a winter project.

Regarding the 150. You have the correct rpm range for it-up to 5500. It is always best to prop the engine to run at the top of the rpm range, or 5500. Running it at 5200 is about one prop size off, even though you are running a low 15 pitch prop.

 

[Faztbullet]

Re: Looking for a winter project.

Depending on what year it is would determine on if I would rebuild it. If its a early model(1978-79) you wont gain much as it the same as your current 150. If its the 1980-85 model(2.6L) it would be worth throwning a few dollars at if it dont need much. The rpm for the early model is 4750-5750rpm and the 2.6L is 5000-6000....

 

[Chas0218]

Re: Looking for a winter project.

Depending on what year it is would determine on if I would rebuild it. If its a early model(1978-79) you wont gain much as it the same as your current 150. If its the 1980-85 model(2.6L) it would be worth throwning a few dollars at if it dont need much. The rpm for the early model is 4750-5750rpm and the 2.6L is 5000-6000....

I am guessing that the current prop would be about perfect for the 235 seeing that is what came off the boat/motor. I will get my father to get the ID# from the back of the motor for me and see what year it is.

Just thought about something, I took the trim/tilt motor off the 235 and it bolted up to my 91 so according to iBoats' part numbers its for a 1982-1990 for the 235hp and 1982-1991 150hp are the same. So would I be wrong to assume this is a 1982 or newer 235?

 

[emdsapmgr]

Re: Looking for a winter project.

Yes. The 91 engine has a two-wire trim motor. OMC went to the two-wire trim motor setup sometime during the 1981 model year. Your engine could be a late 81 or later model.

 

[Faztbullet]

Re: Looking for a winter project.

The late model 235(2.6L) has the potbelly exhaust and different adapter plate. If this is what you have and it dont need a lot of repair i might make this my project. The 2.6L motors are the only stock engine in the sales brochure that have non published hp rating due to it was around 245hp at prop. They quit making this engine as it would outperform the 225 v-6 looper(2.7L) and it is a thirsty motor....

 

[Chas0218]

Re: Looking for a winter project.

The late model 235(2.6L) has the potbelly exhaust and different adapter plate. If this is what you have and it dont need a lot of repair i might make this my project. The 2.6L motors are the only stock engine in the sales brochure that have non published hp rating due to it was around 245hp at prop. They quit making this engine as it would outperform the 225 v-6 looper(2.7L) and it is a thirsty motor....

Thirsty isn't a problem. I didn't buy the boat for its gas mileage. I will get a serial and model number this weekend. I was told the exhaust tubes were rotted out due to salt water but the rest of the motor is supposed to be sound. I mean if this thing doesn't last me more than a few seasons it's fine mainly because I didn't pay anything for this motor and if it only costs a couple hundo it's all in the name of fun. Haha. But the only way I am going to rebuild this is if its the newer 235.

 

[Chas0218]

Re: Looking for a winter project.

Ok so here is the model # and serial #.
Model number: J235TXCNE
Serial number J5704599

If I am not mistaken that is a 1982 Johnson 235. Which is the better 235 model of the 2!!

Let the project begin.:facepalm:

 

[emdsapmgr]

Re: Looking for a winter project.

You have the year correct. That model number is for an extra long shaft engine. Is that 25" the shaft length you need for your boat?