1996 Johnson 60 & 70 Differences - Only the Carbs?

[sailfish]

Hi all, <br />I have twin 1996 Johnson 60hp motors on my 1.6 tonne boat and it is underpowered. I was told that the only difference between the 60 and 70 hp motors is the carbs. Can anyone tell me if this is correct? I did find info that shows the bore & stroke are the same. If the diference is just the carbs, it may be worth me springing for the carbs to get the hp to a reasonable level. The second question would be if the carbs are the same aside from the jets? If I only needed to change jets I would be over the moon!<br /><br />Thanks for any help.<br /><br />Tom

 

[WillyBWright]

Re: 1996 Johnson 60 & 70 Differences - Only the Carbs?

Welcome to iboats. <br /><br />That's not the only difference, but usually the main one (the opening at the venturi is usually larger allowing more fuel and air to flow thru into the cylinders). But save your money. If it helps at all, it'll barely be noticable. The only thing you'll get out of the deal is increased fuel consumption and shorter engine life. I see a lot more old 60s around than 70s. They seem to last a lot longer. Look around for a pair of used V-4s. Even a pair of 90s would make a huge difference over those triples.

 

[sailfish]

Re: 1996 Johnson 60 & 70 Differences - Only the Carbs?

Thanks Willy. The 90's are too heavy for the boat without increasing the pod size, so the cost goes up a fair bit. <br /><br />The manufacturer said that the boat would plane with one 70 whereas that is certainly not the case with the 60 hp. <br /><br />The inlet (bar) here is treacherous at times and with both motors I can stay on the back of a big wave and ride her in, but if I ever lose a motor at sea, I may find myself in a bit of strife getting back in, which is one of the main reasons for owning a dual motor installation in the first place.<br /><br />The boat cruises at about 16 or 17 knots at about 4100 rpm now and uses roughly 1 litre (about a quart) per nautical mile per motor in fuel, so she is pretty thirsty already.<br /><br />I looked at a pair of 90 ETEC's since they are relatively light and would not require the pod mods. Unfortunately, the cost is prohibitive at the moment and the reports on ETEC's I am hearing here are not that good, but mind you this is from a fellow who sells mercs....<br /><br />Thanks again for the help.