Cooling issue Yamaha Enduro 8hp 1992 E8D

[labougie]

I've just acquired this two-stroke motor, s/n 677 L 406611. I'm told that it's based on the much earlier 8B. On starting, the motor seems to pee plenty of water but after a while under load the flow reduces and heats up until it's more steam than water. I changed the impeller as a matter of course when I first got the motor. I've flushed the system through with fresh water and got some crud out of it but not a lot. I suspect the metal plate (oil seal housing?) below the impeller which also houses the lower drive shaft oil seals, and lower drive shaft bushing. The top surface of this plate has a u-shaped waterway which is corroded. Could this be the cause of the problem? Should this housing simply lever out upwards? Will the oil seals and bushing also need to be replaced? Does the bushing need a press to fit it into the housing? Any advice greatly appreciated, thanks.

[TownsendsFJR1300]

That plate if scruffed up at all should be replaced, it will definitly not help your cooling issue and tear up your impellor much faster than a smooth one. The impellor cup should also be smooth.

Here's you parts fisch; http://www.boats.net/parts/search/Ya...201/parts.html to give you an idea how its assembled..

That plate just comes off after the impellor is pulled. There are two seals underneath that due fail over time. On my 06 F150, I just had those seals replaced (preventive maintainance), one seal had failed but no water intrusion...

[labougie]

Thanks, but I think we have a misunderstanding here. The plate I'm speaking of is numbered 11 and the bush is 12 in the parts listing link you quoted while I think you're speaking of part 29, the stainless plate directly under the impeller. The two seals underneath are set into the housing I'm referring to which also has the corroded waterway.

[TownsendsFJR1300]

Thanks, but I think we have a misunderstanding here. The plate I'm speaking of is numbered 11 and the bush is 12 in the parts listing link you quoted while I think you're speaking of part 29, the stainless plate directly under the impeller. The two seals underneath are set into the housing I'm referring to which also has the corroded waterway.

Part #11 and the two seals are to keep water and the LU oil separated. The bushing in there should be able to be removed without a press. The two seals there are what i was referring to earlier.

And yes, that part should come out once bolt #14 comes off.

Those parts shouldn't make any difference on you water flow issue but if the seals are bad, parts corroded, yes, they need replacing. You don't want water getting past those seals..

[labougie]

I need to replace the housing (part number 11 above). What I need to know at this stage is:

1/ Should the housing simply lever out upwards and pull up over the drive shaft? Are there location pins on the underside of the housing or can I tap it sideways to loosen it?

2/ Will the oil seals and bushing also need to be replaced?

3/ If I also replace the bushing, does it need a press to fit it into the housing?

Any advice greatly appreciated, thanks.

[TownsendsFJR1300]

Part #16, per the parts fisch (click on the link) is a dowel pin, so yes, it'll have to come straight up.

I would replace those two seals.. I was told, those two seals, a least for my engine do fail over time and should be replaced after several years. (one of my seals did fail in 6 years of so.) Your already there and their cheap enough, I'd replace them. Pay attention to which direction their installed...

Re the bushing, if its sloppy, outside of spec's, it would need replacement. If your replacing part #11, it appears the bushing comes installed in it already.

If it doesn't, I would replace it as you'll have to remove the old one from the old housing, (potential damage hammering or pressing in a good, HD vise).

Use the appropriate lube on the seals / shaft when assembling (per your manual)

[labougie]

Thanks - I'll let you know how I get on - probably later this year when I store the motor up for the winter.