F100 water pump housing melted

[Earlydog]

I installed the water pump rebuild kit parts on my F100. The motor was still overheating at idle, no tattletale stream, ran fine at speed. I removed the water pump housing again and found the plastic case had been melted, the metal liner deformed and the impeller worn on top. When I installed the metal liner it looked as if there were two spots where the metal tab could align, and I chose the one which seemed to give me the straightest shot through the housing. I also noticed that the drive shaft bushing is pretty ratty looking, might this be related to the pump issue, by allowing the shaft to wallow around? Thanks in advance.

 

[robert graham]

Re: F100 water pump housing melted

The motor must have been run with no water supply, muffs, in a barrel, in the river... Replace the entire water pump(kit)again, plus the thermostat and pressure valve. Don't run the motor if tell tale is not running water. Hopefully your overheated motor is not damaged. Good Luck!

 

[Earlydog]

Re: F100 water pump housing melted

The motor must have been run with no water supply, muffs, in a barrel, in the river... Replace the entire water pump(kit)again, plus the thermostat and pressure valve. Don't run the motor if tell tale is not running water. Hopefully your overheated motor is not damaged. Good Luck!

I wish it were that simple the boat was placed in the water immediately after the rebuild and was always tilted down when running. So today i replaced all of the water pump components including the seal housing which was corroded and is actually part of the water pump from what I can see. Hope that solves the cooling issue... Meanwhile back at the ranch, when I removed the lower unit to service the pump bits and pieces of rubber from the 10 year old drive shaft bushing came off with the unit. The shaft shows evidence of rubbing on the bushing. I've read that the bushing chirping isn't an issue and can be solved with a shot of WD40, but not sure about having chunks missing from it.

A visit to my local dealer was a dead end as he told me, " I've never had to replace a drive shaft bushing, don't know what it is, are you sure it's not the oil seal?" I spent 4 hours getting the snap ring out and am now clueless as how to remove the bushing itself. It's a long reach into a tight spot. I considered inserting a toggle bolt through the bushing and trying to pull it out, but I'm afraid I'd end up with a toggle bolt in the housing if it didn't work.

Thanx in advance.

 

[13' Whaler]

Re: F100 water pump housing melted

This thread is pretty old but it might help others, I ran into the same issue as you with my 1990 225 HP Yamaha. It has a 25" shaft and that bushing had apparently gotten hot. I purchased the 1980 22' Whaler Revenge, engine and trailer last spring so I'm not sure what happened but assume it was probably run on a hose for an extended time or simply wore out. A fully charged battery would make the engine turn but just barely, not even close to starting RPMs. I was concerned that it was an internal engine problem but I bought the whole rig with the idea of installing a new engine but thought I'd give rebuilding the old engine a go.

I couldn't get the lower unit to drop out so I thought the driveshaft was bound up within the engine coupler. I kept beating, prying, wedging and cussing the engine until I was finally able to get the lower unit free from its shackles. Afterwards the engine turned over without problem and the drive shaft turned fine on the bench. (WTH) I looked up in the midsection and was able to see that the culpret was the midsection bushing. I was able to get the snap ring out no problem with a pair of snap ring pliers. Getting the bulging bushing out was another story. Long story short, I basically and very carefully chiseled it out. The bronze housing started to crumble away in pieces after I was able to get a couple good precision hits on it.

I won't be able to run the engine on anything but a hose for a few more months so I just reinstalled the lower unit without it. I purchased a replacement and will be installing it before I do my shakedown cruises on the lake. After that experience, maybe it was just old age which led to its condition but I'd have major concerns running the engine for an extended period of time on the hose with the bushing installed, I'd have to assume that the seawater lubricates and keeps it cool during operations.

Good luck

 

[Earlydog]

Re: F100 water pump housing melted

This thread is pretty old but it might help others, I ran into the same issue as you with my 1990 225 HP Yamaha. It has a 25" shaft and that bushing had apparently gotten hot. I purchased the 1980 22' Whaler Revenge, engine and trailer last spring so I'm not sure what happened...

I couldn't get the lower unit to drop out so I thought the driveshaft was bound up within the engine coupler. I kept beating, prying, wedging and cussing the engine until I was finally able to get the lower unit free from its shackles. Afterwards the engine turned over without problem and the drive shaft turned fine on the bench. (WTH) I looked up in the midsection and was able to see that the culpret was the midsection bushing. I was able to get the snap ring out no problem with a pair of snap ring pliers........


An update. I replaced the water pump on the other (starboard) engine this spring. I found the mid shaft bushing on it was also toast. Not only was the bushing gone, but the annular groove for the snap ring and the shoulder the bushing fits up against had also corroded away. I reinstalled the lower unit without the bushing. I've put about 100 hours on it since then with no apparent problems. My logic was that the bushing had been gone for some time without any symptoms so nothing has changed except knowing there is no bushing there now. I'm sure they put the bushing there for a reason (it's only on the extra long 25" shafts) but so far seems okay without it. Could running without the bushing put additional stress on the engine crankshaft bearings, only time will tell.

 

[boscoe99]

Re: F100 water pump housing melted

Could running without the bushing put additional stress on the engine crankshaft bearings, only time will tell.

Probably not. Many run their Yams after having either removed the bushing entirely or reaming it out somewhat.

Yam now sells a special water resistant grease that is designed to last between annual water pump inspections. As if many even bother to service their motors when they are supposed to.