JimmySmackdown
Cadet
- Joined
- May 2, 2006
- Messages
- 23
Hi everyone. I haven't posted many times here on iBoats, but I wanted to share this experience with the iBoats community because hopefully it will help someone else out who may have experienced problems like mine.
I bought this outboard in 2016 to re-power a duck hunting rig. I had overheat problems the first time I took it out on the water after mounting it on my boat. The engine would be fine from idle up to about 2500 rpm after which the overheat tone would sound. After several trips back to the seller to see if he could figure out what was wrong with it (he called himself a mechanic), including looking at the water pump, it was determined that the poppet valve was to blame and he said that he replaced it. I took it back out on the water and presto - no more overheat horn above 2500. However, when I attempted to shift into reverse, all it would do was a "high speed" grind and would not engage reverse. Forward and neutral were fine, but no reverse.
At the request of the guy I bought it from, I pulled the lower unit drain plug and out came frothy, milky gear case oil. Obviously I had a blown out seal. He asked if I had hit anything, but I hadn't. It was at this point that he wouldn't agree to help me anymore (deadbeat), so I contacted a mechanic that I could trust and had him look at it. He recommended that we rebuild the lower because of the blown out seals and the reluctance to shift into reverse. He also put in a new water pump kit since he had it open. He put it back together and we put it on muffs to test it since his test tank was drained for winter. We had forward, neutral and reverse. Woohoo! I thought my troubles were over. Boy, if I only knew what was in store for me...
Two weeks later, I took the boat out for a layout duck hunting trip to Lake Michigan. It fired up great and idled smoothly, but once again, no reverse. In addition to that, the over-heat horn came on when we were idling out of the harbor (in forward) in the no-wake zone. Good thing I have a reliable kicker. The motor would overheat at idle when in the water (in gear or out of gear), but when I got it above 2500 rpm, the horn would shut off (in gear or out of gear on the warm up lever). I assumed that the poppet valve opened above 2500 and provided sufficient volume to cool the engine. I let my mechanic know, but since this was the last day of the duck season, I figured I had some time to try and figure this out myself during the winter.
I turned to the iBoats forums and just about every other outboard related articles I could get my hands on to discover why it wouldn't shift into reverse and why it was overheating. I picked up a shop manual for my motor and then printed out the forum questions and possible answers for problems with lower units that I had saved to look at later. I never really found an answer for my specific issue and more often than not, it seemed that many people chose to offer the very unhelpful "guess it's time to rebuild your lower" or "time for a new water pump" response. Since I had already had a rebuilt lower and new water pump, that option really didn't apply to my situation and wouldn't have solved anything.
Spring arrived, so I was able to take the boat out of storage and open up the can of worms again. I tried a brand-new controller, new cables, an original controller from 1996 and the original cables. I adjusted the shift throw, I made sure the cables weren't kinked; I tried it without cables, in the water, out of the water. I could get it to shift with the muffs or when the motor was turned off if I was spinning the prop by hand, but never when the motor was in the water. I also noticed that the throw from neutral to reverse lockup was much longer than the throw from neutral to forward lockup. I also noticed that if I had it idling on the muffs, I didn’t get the overheat horn, but if I put it in the water I did.
I finally was able to schedule some time with my mechanic and we decided that the powerhead would need to come off to check the mid and lower exhaust and water gaskets. We lifted off the powerhead and discovered that a piece of gasket (I think they were factory original) had broken off and was stuck in one of the water passages. We blew compressed air through all passages checking for debris. Everything appeared open. We put it back together with new gaskets and looked at the supposedly "newly" replaced poppet valve. The valve was original, the gaskets had not been replaced and they had been smeared with silicone and hastily re-installed but were missing TWO PARTS! I picked up the parts - a bushing and a seal and two gaskets - and we installed them on the valve and put the valve on the motor.
The mechanic and I took the lower apart – again- to see if we could see why it wasn’t shifting properly. We had new gears, new clutch dog, the shift shaft was straight and the splines were sharp and straight, the bearings were new, the carrier retaining nut was round and had good threads, the carrier was new, the locking key was new. Basically everything inside that case was new. It seemed like the entire assembly needed to move forward about 1/8[SUP]th[/SUP] of an inch for reverse to engage, but the bearings, carrier and everything else was bottomed out in the case and the prop shaft lash was way out of spec.
Then, it occurred to my mechanic that he had heard about a few rare lower unit cases that were produced in the 90’s that had a very unusual assembly spec. He had never run across one out of the hundreds of lowers he had rebuilt, but since he was out of ideas he thought he would give it a shot. This was something that no internet forum covered (as far as I know), no other mechanic I had spoken with had heard of.
He put the clutch dog assembly in backward. Yep, backward.
When it went in backward, it put the reverse gear closer to the dog and the forward gear a little further away. It still lined up correctly and everything tightened up to specs. Even the prop shaft lash finally fell into specs. It turns out that I should have read my Mercury manual more closely. On page 551, it says that "On high performance gear cases - CLE, Sport Master and Torque Master - sliding clutch MUST BE INSTALLED with GROOVED RINGS FACING FORWARD GEAR or reverse gear clutch dogs will not occur. I guess I didn't know that I had a high-performance gear case. I do now.
Crap, I wish I was better at reading.
We bolted it up filled it with fresh gear oil and headed to the test tank. It ran perfectly, didn’t overheat at low or high speed and most importantly, I finally had reverse.
I know that this was long winded explanation and I’m sure that there are mechanics out there who may have been able to diagnose and solve both problems with ease, but this is for those of us who might not know much about outboards but are trying to learn – while on a budget. Hopefully it helps somebody else who is plagued with one or more of these issues.
I bought this outboard in 2016 to re-power a duck hunting rig. I had overheat problems the first time I took it out on the water after mounting it on my boat. The engine would be fine from idle up to about 2500 rpm after which the overheat tone would sound. After several trips back to the seller to see if he could figure out what was wrong with it (he called himself a mechanic), including looking at the water pump, it was determined that the poppet valve was to blame and he said that he replaced it. I took it back out on the water and presto - no more overheat horn above 2500. However, when I attempted to shift into reverse, all it would do was a "high speed" grind and would not engage reverse. Forward and neutral were fine, but no reverse.
At the request of the guy I bought it from, I pulled the lower unit drain plug and out came frothy, milky gear case oil. Obviously I had a blown out seal. He asked if I had hit anything, but I hadn't. It was at this point that he wouldn't agree to help me anymore (deadbeat), so I contacted a mechanic that I could trust and had him look at it. He recommended that we rebuild the lower because of the blown out seals and the reluctance to shift into reverse. He also put in a new water pump kit since he had it open. He put it back together and we put it on muffs to test it since his test tank was drained for winter. We had forward, neutral and reverse. Woohoo! I thought my troubles were over. Boy, if I only knew what was in store for me...
Two weeks later, I took the boat out for a layout duck hunting trip to Lake Michigan. It fired up great and idled smoothly, but once again, no reverse. In addition to that, the over-heat horn came on when we were idling out of the harbor (in forward) in the no-wake zone. Good thing I have a reliable kicker. The motor would overheat at idle when in the water (in gear or out of gear), but when I got it above 2500 rpm, the horn would shut off (in gear or out of gear on the warm up lever). I assumed that the poppet valve opened above 2500 and provided sufficient volume to cool the engine. I let my mechanic know, but since this was the last day of the duck season, I figured I had some time to try and figure this out myself during the winter.
I turned to the iBoats forums and just about every other outboard related articles I could get my hands on to discover why it wouldn't shift into reverse and why it was overheating. I picked up a shop manual for my motor and then printed out the forum questions and possible answers for problems with lower units that I had saved to look at later. I never really found an answer for my specific issue and more often than not, it seemed that many people chose to offer the very unhelpful "guess it's time to rebuild your lower" or "time for a new water pump" response. Since I had already had a rebuilt lower and new water pump, that option really didn't apply to my situation and wouldn't have solved anything.
Spring arrived, so I was able to take the boat out of storage and open up the can of worms again. I tried a brand-new controller, new cables, an original controller from 1996 and the original cables. I adjusted the shift throw, I made sure the cables weren't kinked; I tried it without cables, in the water, out of the water. I could get it to shift with the muffs or when the motor was turned off if I was spinning the prop by hand, but never when the motor was in the water. I also noticed that the throw from neutral to reverse lockup was much longer than the throw from neutral to forward lockup. I also noticed that if I had it idling on the muffs, I didn’t get the overheat horn, but if I put it in the water I did.
I finally was able to schedule some time with my mechanic and we decided that the powerhead would need to come off to check the mid and lower exhaust and water gaskets. We lifted off the powerhead and discovered that a piece of gasket (I think they were factory original) had broken off and was stuck in one of the water passages. We blew compressed air through all passages checking for debris. Everything appeared open. We put it back together with new gaskets and looked at the supposedly "newly" replaced poppet valve. The valve was original, the gaskets had not been replaced and they had been smeared with silicone and hastily re-installed but were missing TWO PARTS! I picked up the parts - a bushing and a seal and two gaskets - and we installed them on the valve and put the valve on the motor.
The mechanic and I took the lower apart – again- to see if we could see why it wasn’t shifting properly. We had new gears, new clutch dog, the shift shaft was straight and the splines were sharp and straight, the bearings were new, the carrier retaining nut was round and had good threads, the carrier was new, the locking key was new. Basically everything inside that case was new. It seemed like the entire assembly needed to move forward about 1/8[SUP]th[/SUP] of an inch for reverse to engage, but the bearings, carrier and everything else was bottomed out in the case and the prop shaft lash was way out of spec.
Then, it occurred to my mechanic that he had heard about a few rare lower unit cases that were produced in the 90’s that had a very unusual assembly spec. He had never run across one out of the hundreds of lowers he had rebuilt, but since he was out of ideas he thought he would give it a shot. This was something that no internet forum covered (as far as I know), no other mechanic I had spoken with had heard of.
He put the clutch dog assembly in backward. Yep, backward.
When it went in backward, it put the reverse gear closer to the dog and the forward gear a little further away. It still lined up correctly and everything tightened up to specs. Even the prop shaft lash finally fell into specs. It turns out that I should have read my Mercury manual more closely. On page 551, it says that "On high performance gear cases - CLE, Sport Master and Torque Master - sliding clutch MUST BE INSTALLED with GROOVED RINGS FACING FORWARD GEAR or reverse gear clutch dogs will not occur. I guess I didn't know that I had a high-performance gear case. I do now.
Crap, I wish I was better at reading.
We bolted it up filled it with fresh gear oil and headed to the test tank. It ran perfectly, didn’t overheat at low or high speed and most importantly, I finally had reverse.
I know that this was long winded explanation and I’m sure that there are mechanics out there who may have been able to diagnose and solve both problems with ease, but this is for those of us who might not know much about outboards but are trying to learn – while on a budget. Hopefully it helps somebody else who is plagued with one or more of these issues.