just found your channel. Nice job on all of your repair engines. I have been an outboard mechanic almost half a century now. It's great seeing these, I have many of the same ones or similar in my drive carport right now lol. Pluse some nice big v6 and v4's. I am always amazed at how well a 4 or 7 hp outboard can move a light aluminum boat like yours. Keep it up, you are doing great. lol I actually have three different era 15 johnsons, a 20, twin merc 9.8's identical to yours and misc stuff too. A 56 and 61 16 as well. take care...
Looks like a 1980 model, this first for this new design. Always liked these engines even though they have a few unforgiveable design flaws. They don't idle as nicely as the old style 6hp they replace, but run rings around them at high speed.
What was the top speed? I have an 8hp I rebuilt with new sierra pistons and top speed is only 13MPH pushing a light 12ft aluminum. Makes no difference if there is one or two people in the boat.
I’d assume around 14-15 mph. Obviously check compression and make sure the carb is clean and you have good plugs. Also, make sure your throttle linkage is not broken and that your carb is opening all the way at full throttle. Sounds like it is a propping issue. Have you tried a higher pitch prop?
@@tylerott9269 No I haven't, it has the standard pitch 9" prop. I've checked all the things you mentioned compression is 125 psi on both cylinders and only get 5000 rpm. Other than the perceived lack of performance it runs great. There's one youtuber who shows his gps speed at 19-20 mph but didn't mention his rpm or prop pitch. Thanks for the reply
@@johndkoop from what you are saying, everything seems normal to me. A good 7.5 will do about 15 mph from my experience and your rpm seems good. Have you tried different trim with the motor or tried jacking the motor up on the transom?
@@tylerott9269 I jacked up the transom so the cav plate is flush with the bottom of the boat and tried different trims not much changes. Most folks would be happy that it runs as well as it does . I've got a couple of ideas I'll try winter has set in up here in B.C. so it will be a spring project. Thanks again !
just found your channel. Nice job on all of your repair engines. I have been an outboard mechanic almost half a century now. It's great seeing these, I have many of the same ones or similar in my drive carport right now lol. Pluse some nice big v6 and v4's. I am always amazed at how well a 4 or 7 hp outboard can move a light aluminum boat like yours. Keep it up, you are doing great. lol I actually have three different era 15 johnsons, a 20, twin merc 9.8's identical to yours and misc stuff too. A 56 and 61 16 as well. take care...
I haver one , here in Brazil
Makes me miss my 1980 15 Evinrude miss that motor
I haven’t been able to try out a 15 OMC from that era yet, but I hear they are great motors.
@@tylerott9269 They are I got 25.1 mph out of it on my 1442 Flatbottom fully loaded! With just me and my gear bass fishing 🎣
Yep, these were some of the best engines ever
@@fleetwin1 Yes I agree
Looks like a 1980 model, this first for this new design. Always liked these engines even though they have a few unforgiveable design flaws. They don't idle as nicely as the old style 6hp they replace, but run rings around them at high speed.
Yep, alot of power for a little engine for sure
What was the top speed? I have an 8hp I rebuilt with new sierra pistons and top speed is only 13MPH pushing a light 12ft aluminum. Makes no difference if there is one or two people in the boat.
I’d assume around 14-15 mph. Obviously check compression and make sure the carb is clean and you have good plugs. Also, make sure your throttle linkage is not broken and that your carb is opening all the way at full throttle. Sounds like it is a propping issue. Have you tried a higher pitch prop?
@@tylerott9269 No I haven't, it has the standard pitch 9" prop. I've checked all the things you mentioned compression is 125 psi on both cylinders and only get 5000 rpm. Other than the perceived lack of performance it runs great. There's one youtuber who shows his gps speed at 19-20 mph but didn't mention his rpm or prop pitch. Thanks for the reply
@@johndkoop from what you are saying, everything seems normal to me. A good 7.5 will do about 15 mph from my experience and your rpm seems good. Have you tried different trim with the motor or tried jacking the motor up on the transom?
@@tylerott9269 I jacked up the transom so the cav plate is flush with the bottom of the boat and tried different trims not much changes. Most folks would be happy that it runs as well as it does . I've got a couple of ideas I'll try winter has set in up here in B.C. so it will be a spring project. Thanks again !