150 Johnson-- To buy or Not to buy??

[jarway]

I have posted here before about an older Johnson engine I was considering to buy to put on a SeaNymph CenterConsole I am re-building. I passed on that deal based on everyone's advice-- especially about the boat that came with it for free and the idea of a fiberglass lawn ornament. <br /><br />I have found an early 80's vintage Johnson 150 and if I remember right I believe that some previous advice discussed early vs. late 80's Johnson's and a re-design giving more HP from the late 80's.<br /><br />This one comes with PTT and control cables and a semi-warranty-- will return $$ if engine fails. Asking price is $1200 to $1500. Sorry I don't have the model numbers as yet. It is a freshwater motor off of a deck boat. Anything in particular I should look for on this vintage Johnson?<br /><br />Thanks in advance for any advice.

 

[Solittle]

Re: 150 Johnson-- To buy or Not to buy??

Well jarway seems to me that 150 hp is 150 hp no matter the design. The important thing is the condition. It may very well be worth $12-1500.<br /><br />What is a semi-warranty?

 

[jarway]

Re: 150 Johnson-- To buy or Not to buy??

I agree SL but was curious to know about performance and peculiar problems to this model Johnson. The semi-warranty is if it gives me problems, I get $$ back. Seems like a reasonable deal to me.

 

[gsbodine]

Re: 150 Johnson-- To buy or Not to buy??

As with any motor, check compression. All that does is tell you that the basics of the motor are solid and that it likely won't need a rebuild immediately--very important on a motor that old. Also, I guess your "semi-warranty" is sort of like an extended sea trial thing. You can return it if you aren't happy with the way it performs. That's a good thing.<br /><br />Maybe what you are talking about in HP around those years is that I think very early 80's motors had the horsepower measured at the driveshaft instead of at the prop like later and current model motors. That results in slightly more power from a newer motor marked 150 than an older one marked 150. I am not an engine mechanic by a LONG shot, and if you have specific questions about a specific year model motor, you should ask it up in the Johnson forum. The guys there could help you out. <br /><br />I've got a 1978 Johnson 150 that I have been most pleased with for its age (and cost ).

 

[Boilermaker]

Re: 150 Johnson-- To buy or Not to buy??

Besides compression test>>>maybe pull a little lower unit oil out of the the lower end & make sure its not loaded with metal bits, or water(milky look). Get that SEMI-WARRENTY in writing!<br />Good luck

 

[jarway]

Re: 150 Johnson-- To buy or Not to buy??

Thanks ON and BM. Your suggestions have merit and will plan to follow through on them. ON-- the issue regarding re-tooling by OMC was advised on a question I posed a while back regarding a sinmilar motor. Was advised that newer (late 80's and later) OMC engines had higher HP output at lower listed HP, ie. an early 80' 115 would be equivalent to a late 80's 90HP. Don't know if this is the case??

 

[gsbodine]

Re: 150 Johnson-- To buy or Not to buy??

Originally posted by jarway:<br />... an early 80' 115 would be equivalent to a late 80's 90HP...

I have heard this too, but only as it is related to the fact that the early 80's motor would have 115 HP at the crankshaft and therefore somewhat lower horsepower at the prop because of the transfer through the driveshaft, etc. (though 90 seems low to me, losing 25HP seems too much just on a common sense level--I'm not an engineer) and the late 80's motors are rated *at the prop* already, thus making a new 150 have a higher usable HP output than an older one.<br /><br />I have heard that the '83 model year (I think) is when all manufacturers had to rate HP at the prop. Before that point, some did, some didn't.\<br /><br />HTH,<br />ON

 

[Winger Ed.]

Re: 150 Johnson-- To buy or Not to buy??

New engines cost about $100 per horsepower.<br /><br />Used ones generally run about $10 a horsepower; if they run and are over about 15 years old.<br /><br />..<br /><br />The difference between buying a Merc. or a Johnson under those circumstances is the free stuff you get with the engine.<br /><br />Such as--- with the Johnson or Evinrude it is control cables, steering gear, or maybe even a boat & trailer. <br /><br />With the Merc. it might just be that the seller hands you enough beer that you don't ask too many questions he really doesn't want to answer as you write him his check after you've loaded it in your truck.<br /><br />...<br /><br />In your case:<br /><br />12-1500 is fair. IF!!! you can hear that engine run, even on a hose.<br /><br />And, while its running, idle it down, and down, until you can see the timing marks fly by with the naked eye,,, something around 6-7OO if it has a tach.<br /><br />If that motor will do that,,,, you're getting a bargain.<br /><br /><br />Provided it cranks & starts in about 2 seconds or less:<br /><br />Ideling that slow tells you the carbs & ignition guts are in good shape, and the compression is REAL! good. <br /><br /><br />If a boat motor does all that--- a new one costing $10,000 more won't run any better.<br /><br />And with buying a new engine that size from a dealer, you won't get a free boat & trailer, or meet any new friends, and they won't get you drunk before you write them a check for it. <br /><br /><br />Ed.

 

[BF]

Re: 150 Johnson-- To buy or Not to buy??

all sounds like good advice so far.... but I'm not sure that it should idle down that low if it's running on a hose. Without exhaust back-pressure it'll have a faster idle, than it would on a boat in the water. If it idles down to 600 on the hose, i'd bet it'll be too low in the water and stall when it's put in gear.<br /><br />ditto on doing a compression test and pull the lower unit drain plug (for a second) to check for water & fillings. Do these BEFORE you hand over cash... Also, before finalizing the sale, don't forget to ask about an owner's manual, service manual and any spare parts they may have for the motor (e.g. prop?)... a lot of times folks are glad to hand that stuff over for no extra cost to get a sale, but if buyer doesn't ask, they'll hold on to stuff to sell separately (or just collect dust). Worst case is that they don't have anything... but maybe it'd save you buying a prop (they might have re-propped it for the deckboat and have the original around as a spare).<br /><br />good luck.