35 hp, 1978, recent rebuild but won't start

[sam03v]

Re: water pump and flushing device/ear muffs

Re: water pump and flushing device/ear muffs

The water pump was submerged was it?

What did you do precisely when you serviced the water pump? Has it got a plastic housing and was it replaced?

Maybe it wasn't submerged. I hope i'm not that stupid...I thought it was way past the pump, but i'll check it again.

I bought a pump kit which had an impeller, new plastic housing , gaskets, and metal cup. I smeared a little gear oil in the cup, and rotated the shaft until the pump housing slid over the impeller. I also used gasket sealer on both gaskets. One possibility is the plastic key that holds the impeller in place. The kit didn't come with one so I made one out of hard plastic. It worked fine, but maybe it came out some how...I'll check it out tonight....

 

[Paul Moir]

Re: water pump and flushing device/ear muffs

Re: water pump and flushing device/ear muffs

Ok, just wanted to make sure the pump housing wasn't distorted. That can easily happen when an impeller gets fried.

I don't think that pump like the earlier ones had to be submerged to prime, just water up over the cavitation plate. I expect someone will correct me if I'm wrong here.

I once did something really stupid, and this sort of reminds me of it. I greased the impeller like you did. I then proceeded to install the impeller with the vanes pointing in the wrong direction. Normally if you do this, the vanes simply flip over, but I guess that grease was enough to keep them from doing that. Needless to say the pump didn't work until I pulled it apart, cleaned the grease off and flipped it over.

Rather than use grease on your impellers, which can harm the rubber in addition to that problem, use soap. It disappates once the engine is run and does not harm the rubber.

The impeller key's I'm familiar with are metal. But I really don't know much about the late 70s engines.

 

[fireman57]

Re: 35 hp, 1978, recent rebuild but won't start

Sometimes it takes five or six scary seconds for the water to start exiting the telltale. The father in trash can or barrel that you have the engine in the quicker the telltale will run. Ideally you want to have it in the barrel where it sits in the water while on your boat. The back pressure in this depth will be what it really is on the water. Paul is very correct about the vanes and grease. He also has a fantastic style on how to get his point across. I hope that I can pick up on that someday. He is one of the very best.

 

[sam03v]

Re: 35 hp, 1978, recent rebuild but won't start

Well I guess I am that stupid... I thought as long as the vents on the lower unit were in water, the pump would prime itself, since the flushing device only covers the vents.. Anyway I filled the can so the level was above the pump, started the motor and water came out the indicator hole. Stopped the motor, put the thermostat back in and started it back up.

I had it idling half way decent, and it doesn't seem to get overly hot.There's still a slight miss, but I think I'll smooth that out eventually. I might still buy some of those temperature crayons to double check the temp of the engine.

I also need a tachometer. Do you guys know of any hand held tach's that can be mounted temporarily for tuning engines? This is a tiller motor, the boat doens't have any instrumentation.

thanks again!

 

[Paul Moir]

Re: 35 hp, 1978, recent rebuild but won't start

The simplest solution for the tachometer is a tinytach from tinytach.com (phone to order!). Infrared tachometers are getting pretty cheap now but they're a handful if you're trying to do this alone. However I find they come in handy for all sorts of different things.

 

[BF]

Re: 35 hp, 1978, recent rebuild but won't start

as for your Q #2 way up there, I think it means that when you're in fwd, when you set throttle wide open, you should verify that the throttle linkage (under the rotating ignition plate) actually hits the end-stop. Engine doesn't need to be running to check this. If not, putting the throttle to full open isn't actually getting the maximum timing advance. Engine needs to be in fwd, because in neutral the maximum throttle opening is restricted so to not go above the "start" range.

Hope this helps.

 

[sam03v]

Re: 35 hp, 1978, recent rebuild but won't start

as for your Q #2 way up there, I think it means that when you're in fwd, when you set throttle wide open, you should verify that the throttle linkage (under the rotating ignition plate) actually hits the end-stop. Engine doesn't need to be running to check this. If not, putting the throttle to full open isn't actually getting the maximum timing advance. Engine needs to be in fwd, because in neutral the maximum throttle opening is restricted so to not go above the "start" range.

Hope this helps.

Your exactly right. I got it adjusted correctly the same day I discovered there was not enough water in the test can. I also have to adjust that stop to get the proper timing advance. I found a cheap portable tachometer on ebay that I'm hoping will help me with that step.

thanks for the reply.