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Questions about 115 Johnsons

bill_w

bill_w

Advanced Contributor
Hi. I just bought two 115 hp Johnsons, one is a 1980, and one is a 1995, and I already own a sick 1989..

Question 1. The '95 was run with a blown head gasket, and the combustion gasses eroded a small portion of the aluminium block around the steel sleeve. The sleeve is good, the head is good. So, can I just replace the head gasket, and carry on??

Question 2. What is the difference between the motors with a 'bubble' exhaust cover, and a flat exhaust cover? The 1980 and the '89 have the flat back covers, and the '95 has a 'bubble' back cover.

The '80 runs, but the first owner says its 'tired', thats why he took it off his boat. I haven't done a compression check, but if the compression is low, and the cylinders aren't scored, would just a new set of rings help? He also mentioned that it was getting difficult to start cold. Would the compression figure into this too?

thanks in advance,
Bill
 
The 80s modle engine came with a piston known as a high ring thus engine had higher compression when lead free fuel was introduced the head gaskets needed to be changed to lower the compression around 90 to 120 if the pistons wernt replaced by the dealer covered by omc typicaly compression reeding is between 120 to 140 you may want to consider a different power head however they will inter change.the pistons in this engine if good are sought out by performance minded folks. but require high octane fuel and propper timing to prevent RAD AKA RAPID ENGINE DESTRUCTION I built a stinger 70 with j plate exhaust modified with expansion pipes thru the exhaust plate with agressive exhaust porting 185lb compression was acheved with high ring pistons and still had clearence to allow for piston expansion due to NOX theree v4 dubble throte carbs mounted to a on off reed plate milled from a single stock of t60 61 aluminum stock completed with volicity stacks. charge coils were removed stater frame was rewound for ing olny top off with a custume milled supper light flywheel mounted on a custome one off allison speeds over 100 mph plus, not a dailey driver however if your the type that likes speed heres your chance to have some fun and spend lots of money.The bubble back motor will inter change as well this block with the large exhaust was also used on larger hp modles by johnson evenrude.
 
by the way the 95 block was known to be thin in spots, the older motor was cast were the 95 block was produced using a new method called loss foam' a sand form surounded a block of foam in the shape of the engine block. when molten alluminum was pored in the foam melted away. this was a time and cost saving process however the blocks were poris these blocks used in salt water would be eaten from the inside out, this condition is easly spoted by inspecting around the head gaskets. you might consider rebuilding your motor solid platform.
 
Need to know -----------Are you sure that the 115 HP here is a " lost foam " cast motor ???-------------With a head gasket it would be the same old standard cross flow that is being asked about.
 
Need to know...sounds like a nice motor you built..but I'm after a daily driver. I really don't want to get into rebuilding right now, or I'd be working on the 89 with bad bearings. I would really like to get the '95 onto my sidewinder, mainly because its got more horses (prop vs flywheel rating), and the fact its 15 years newer.

So, is the '95 worth trying to fix with just a head gasket replacement? The head gasket does seal against the steel sleeve, so I'm thinking it should be OK. I could just drop the tired '80 onto the boat, but if the '95 is good, why bother? I don't have a proper shop or equipment to lift 350 lbs on and off over and over again. I'm using a tree branch and a chain block.

Again, what's with the bubble back exhaust? Is it for additional performance, or a quieter engine?

Thanks,
Bill
 
racerone i think the 95 is a el gl or sx 60 degree the way he decribed the head o ring style? but not sure about the bubble back 60 degree could be mistaken with the cast exhaust hump. bill w can you read the modle number on the 95 whould be helpfull do you have 4 plastic carbs or 2 aluminum 4 whould make this a 60 degree. cool mtr marketed as the lightest and fastist when released.
 
In 1995, both the traditional 1.6L cross flow motor, and the new 1.7L 60 degree eagle V4 were produced. They overlapped from 1995 to 1997. The eagle block was lost foam cast. I'm not aware of any substantial issues with the eagle V4's. The 1991-1992 eagle V6's had a thin spot that could allow water behind the #1 sleeve if it cracked.

The cross flow was simple, efficient, and reliable. It produced good power. The eagle V4 is a great deal more powerful. While not as simple, it is very reliable. Power requires fuel, and the eagle block will typically use more fuel than a cross flow of the same hp in both V4 and V6 configurations.

The bubble back tuned the exhaust for more power. When the engines were re-rated (prop vs crank) the old 140 became 115. The 115 became a 90. The new 140 and 120 were based on the 1.8L looper block that was introduced in 1985. (later punched out to 2.0L)
 
Model No. is VJ115TLEIE...what does that make it? I can't get at the carbs to see, its lying in the back of my p/u on its side, and the truck is piled to the top of the cap with work stuff.
 
I just answered my own question..its not a 95, but a 91. So, is 91 rated at the prop or crank? Gonna have to start taking the model guide with me on shopping trips. And what about the head issue..I just looked at the old gasket again....it looks like the leak was contained to inside the water jacket..didn't come right through to outside the block. Will just a new gasket fix it???

Also, the water deflector (rubber tube thing) in the block was sort of crooked, and not quite where it should be according to diagrams I've seen. So, this could have been the reason for the overheating in the one area.
 
hey bill you have a 1991 115hp crossflow solid motor easy to work on parts are abundet an easy on the pocket. this is the platform that earned johnson there rep for relibilty. most marine mec cut there teeth on this one. one concern the block needs to be built up using a very small drill bit drill severial holes ajecent to sleve in week area dremmel out loose alluminum treat with muriatic acid neutrialize with baking soda and water. heat with blow dryer apply 2 part epoxy such as belzona [approved by the navy used widley in norfolk va.] jb weld will do allow to cure severial days the package may say ///// but most are not fully cured under 24hrs known as post cure simply deck block with 80 grit best if wraped on aluminum stock or 1in thick plexy the rubber tubes are known as deflectors must be instaled correctly once you clean things you should see the ridges they slid between removing the old ones can be tricky let me know. you may want to remove exhaust plate and filler blocks look for any clean areas in exhaust like they have been steem cleaned. if none clean carbon reinstall. t stats and pressure relief valves should be inspected or replaced as this is a very difficult task with power head mounted on tuner.
 
Need to Know...good call about thermostats. Port side was siezed/melted, spring totally gone. Port side pressure relief valve also melted, on the cover side, not the block side. I did the JB weld trick on the cylinder, it looks like it will work ok. The water deflectors in the block on the port side were also gone, the upper one was partially melted, the lower one had moved, and was bent like a boomarang. The block and head don't show any signs of overheating ??? I pulled off the exhaust cover and plate, cleaned out a bit of carbon, not much. The exhaust filler blocks??? Are these the pieces held into the block by 3 bolts?? Fit behind the exhaust plate on each side of the central water jacket?? I didn't pull them, because I didn't know what was behind them. Should they be flush with the rest of the rear block? The port side is sorta recessed a bit, say about 1/64 to 1/32". Will the new gasket fill that gap??
 
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