1990 Johnson 60hp VRO

[rebars1]

New to us 1990 Johnson 60hp (VRO disconected), 18' Boston Whaler. We finally took it out yesterday for ocean trials. 5500 WOT, 26 knots. Ran at WOT for a couple of miles, then slowed down to about 2000 prms and the hot engine alarm went off. We shut it off, let it cool for a couple of minutes then started it back up with no alarm sound. We went back at a slower speed with no problems. It has a new impeller, flushed out system, strong tell-tale squirt.

1. Did it over heat from going from WOT to slow too quickly? Is it better to slow down gradually?

2. Is it OK to run at WOT for long periods of time, or is it better to run at 5000 or 4000 rpm?

3. Is it OK to run at idle or a low speed for trolling or does that lug the engine?

 

[tashasdaddy]

Re: 1990 Johnson 60hp VRO

just because you have a strong tale tell, does not mean the thremostat is opening an cooling the motor. i would first do a compression check, to see if any damage was done. if the reading are 100PSI +. and within 10% of each other, it would change the thremostat. your now recommended rpms are 5000-6000, rather see 5800, but you are in range.

being properly propped and you are close, it is fine to run wide open, and to go from stop to wot. they are built to run wot for long range, and fine to troll.

the system as an auto shut down when it runs hot, thats why it went to 2000rpms.

 

[JB]

Re: 1990 Johnson 60hp VRO

That Whaler is a lot of boat to push for a 60HP. It is rated for 150HP (if it is a classic Outrage). We usually recommend at least 70% of rated power for good performance. That would be around 100HP. Whalers are usually lightweight for their power rating, but 60HP seems underpowered to me.

You do seem to be correctly propped, though. 5500rpm is a fairly good top end.

It is usually much more economical to run 3,000 to 4,000 rpm with an outboard that is in the recommended power range, but your 60 needs WOT to get the cruising speed that a 115 or so would give you at 3,000rpm. I don't think I would run it at top speed for long, though they seem to be able to run at WOT for long periods without problems.

That three cylinder looper is and excellent engine. I have trolled the 70HP version for hours on end with no trouble.

Bottom line? I think pushing an 18' is working your 60HP too hard at WOT, even with the right prop. I recommend that you go to at least 100HP.

My dream power for an Outrage 18 would be a Suzuki DF140 or its Johnson version.

 

[rebars1]

Re: 1990 Johnson 60hp VRO

Thanks JB:
We are not that used to outboards.

Agree the motor is a bit small for this boat.

Actually, even though the paperwork and the logo on the side says BW, I think it may be a clone. It is narrower than the other BW's and the front side fins hull shape is different from the classic BW lines.

 

[rebars1]

Re: 1990 Johnson 60hp VRO

I replaced the thermostat when I brought the boat home. For testing purposes, would it be OK to remove the thermostat and run the motor without it for a day to see if the alarm still comes on?

Is there a way to install a water temperature dash guage and sensor on this engine?

 

[JB]

Re: 1990 Johnson 60hp VRO

I would not run it without a T'stat.

Need to see a pic of the boat.