Johnson 175 (150?) vs Mercury 200

I have a 1979 Johnson 175 (after talking to mechanics it may be a 150). The engine needs a complete rebuild, which I can have done for $2200. (as long as crank is OK) <br />I have the opportunity to purchase a 1980 model Mercury 200 on a 18' Checkmate w/ trailer for $3000. This motor had a complete rebuild a couple of years ago. I took it for a test drive and it seemed to be OK. It did start immediately when cold. (Something the Johnson nver did!) I did notice that the motor was louder (had more bark!) than the Johnson. I did have soundproofing on the Johnson cowl, so this could be part of it. Also, the Merc has external power trim, which I guess is OK, but it is also kind of loud.' It does have dual cable steering, and a concealed control box.<br /><br />I am considering buying this and swapping the motors, and then reselling the Johnson motor and Checkmate. I plan on doing the swap myself.<br /><br />Is this a good idea?? I'll have to swap all of the control cables. Also, will the motors fit on the same holes on the transom.?<br /><br />What about this model and year of Merc?<br /><br />Thanks for any insight. I would like to decide in a couple of days.<br /><br />Rick

Re: Johnson 175 (150?) vs Mercury 200

Experts, any thoughts????<br /> <br /><br />Thanks<br /><br />Rick

Re: Johnson 175 (150?) vs Mercury 200

Anyone have any thoughts????? I need to make a decision soon!!

Re: Johnson 175 (150?) vs Mercury 200

Either motor will give you outstanding performance. A recommendation on the swap would depend on the condition and history of both motors. All you have told us is that one starts easier than the other and is louder - - not much to make a call on.

Re: Johnson 175 (150?) vs Mercury 200

The 200 merc was rebuilt about 3 years ago. It and the boat were taken in by the dealer because the owner could not pay for the rebuild. It has been sitting for the entire time. It looks good on the inside, and started and ran well. The prop is aluminum and needs to be replaced with a stainless. The cost of the Merc, Checkmate boat and trailer is $3000.<br /><br />The Johnson has 2 bad cylinders and needs a rebuild, about $2200 unless it needs a crank. Not sure about the cost then. Also, I always thought that it was a 175. However, a couple of mechanics have told me that because of the shape of the water jacket plate between the heads (which is flat) , it may actually be a 150<br /><br />If I do this swap, I'll plan on reselling the Johnson and the Check mate boat.<br /><br />Sorry this is not real specific. The extra HP would be nice, as well as the dual steering and control box. Not crazy about the external trim on the Merc though.<br /><br />Thanks again for your thoughts,<br /><br />Rick

Re: Johnson 175 (150?) vs Mercury 200

I would do a compression test and leakdown test for sure. Post results!

Re: Johnson 175 (150?) vs Mercury 200

Good idea. I'll plan on doing that as well as checking the grease in the lower unit for water.<br /><br />Thanks

Re: Johnson 175 (150?) vs Mercury 200

Well, I made the purchase today. Hope I did the right thing. I checked the receipts from the motor rebuild and all pistons were replaced as well as the crankshaft. The block was also rebored. Also, the lower unit was pressure tested<br /><br />I checked the compression before the purchase. All 3 cylinders on the port side were about 120-125psi. The cylinders on the right were between 105 and 115 psi. Could this be because the rings have not seated yet??? Also, all of the cylinders leaked down at the same rate.<br /><br />Hopefully this motor is going to be OK. I began the swap today. It has dual steering, which I plan on transferring. I am having a problem getting the Checkmate Steering box off. I think that it may need a steering wheel puller. (I've got the wheel off, but can't get the rest of the assembly off). I'll put a question on the boating forum about this, unless someone has an idea.<br /><br />Thanks