[piotrp]

It was pumping some water when I ran it is a test tank, especially with a few revs, but hardly any when I dropped the revs to near tick over. I dont know if this is normal. There are one or two videos of these running on youtube and some seemed to be chucking out more water than mine. I also dropped the leg to check the impellor, fortunately no bolts seized and it came off quite easily. The impellor look in good condition to me, but not being familiar I wouldn't really know, here it is:
here

[chorchonga]

Yes the serial number makes it a 1984 model more

[MrFlibble]

Is anyone able to offer any advice on this version. I am not too sure what the ideal spark plug is or the plug gap. I havent had a look at the points yet, but any advice on setting them also if I need to would be great. I am assuming it i8s best to run this on 50:1?

[alethiophile]

Not sure if I should be adding some instant gasket to that seal or not when I re-assemble it? I also squirted some limescale cleaner through the head while I had it in bits and it seemed to flow through quite well afterwards with a few bits of gunk coming out in the water. Hopefully this will help. [links]

[lachesis]

Here is a photo of it minus the cowl and the tank.

[ech]

Marine Pump and Part Corporation, manufacture and sale of outboard motor water pump replacement parts and repair kits, a ISO9001 certified company located in America. From the marine rubber products like impellers, gaskets, washers and seals, to the other plastic and metal components for a total water pump rebuild, we can provide quality boat accessories covering your marine pump replacement needs. The impellers with hundreds of models can be applied in the outboard engines like Yamaha motor, Johnson Evinrude motor, Chrysler Force motor, Mercury Mariner motor and so on, with the power range from 2HP to 300HP. With commitment to high quality and competitive price, we can provide a variety of outboard water pump parts to meet you marine engine solutions. here

[allinvain]

more

[FreedomFirst]

[tddk]

[links]

[kenjo]

[puddinpop]

PLEASE NOTE: Most outboard parts are specific to certain models & year series. And cannot be held responsible if you do not provide engine model and serial number with order We advise you to attach your model and serial number at the time of order to ensure the part is correct for your engine. here

[pavelo]

Please Call 01252317100 With model and serial number for advice from one of our engineers on spares/parts for your engine more

[davux]

[srf21c]

[links]

[Jameson]

[aaaxxx]

I'm thrilled to have the info about how to get the impeller out now.. I know its working.. but its an old engine and I think it would be no harm to put a fresh one in there.. especially since I didn't come across a single gasket or seal during the entire disassembly.. heh. [links]

[markhudsn36]

I've got the foot off now..impeller is in the usual place, however problem continues with the shaft from the power head down to the gearbox is joined just above the impeller. in somewhere amongst the rust and corrosion should be a pin 8uggered if I can find it. of course the impeller will not go over the shoulder and up the shaft and next course of action is to strip the little g/box and see if I can do it from the other end. here

[jrrr4518]

I forgot to say that a good bit of the day was taken up through the actions once again of a previous owner who had clearly either lost a bolt or stripped the thread of one of the two locating points for securing the water pump housing to the lower leg and had dealt with that by installing a self tapper, which had then sheared off leaving a small ragged stud which was very very difficult to drill out even with a pillar drill. The result is not pretty but it is now secured by two screws as intended by Yamaha.

[dangerman]

[/ QUOTE ] That has got f,n & r gears so the pump must be driven by the drive shaft or it will get no cooling water when in neutral. In the little ones with a fixed drive the pump can be on the prop shaft because it is always turning. IIRC the little Johnyrudes are like that but i do not know about the Yammies more

[jgarzik]

[/ QUOTE ] Car radiator cleaner probably not likely to be any good, an acid based kettle descaler probably better or an acid based central heating boiler descaler. As a last resort hydrochloric acid (brick cleaner)

[jarlethaanthonyt]

One reason for suspecting the impeller rather than the water passages is that when I tried to start it after the winter the whole engine was very 'stiff'..not tight piston in bore type stiff..more the sort of tightness one would get from an out of shape impeller, cleared after a while of running in a tub but no tell tail after that.