Johnson 35 hp '81- no tell tale stream in test tub

[docksider]

I just started my Johnson 35 HP (1981) for the first time in two years. As expected, it started right up, but I didn't see any stream of water flowing from the tell tale. I can't remember if this is typical at idle or if it is truly an indication of impeller or water pump issues. I suspect the latter, but wanted to check here first. Obviously I didn't let the motor run long (may 30 seconds) given this concern.

 

[tomhath]

How deep into the test tank did you have it? I try to get it as deep as I can to prime the pump. If you still don't get anything it sounds like time to replace the impeller, not difficult or expensive.

 

[emdsapmgr]

Check to see if he telltale hose is still open from the exhaust manifold to the nozzle in the lower cowling. If the engine was run in shallow water, sometimes it will suck up sand/debris which will clog the telltale hose.... You can use a pc of weed whacker string to unclog it. (or air pressure from a compressor.)

 

[docksider]

The test tank was a rubbermaid tub with the water level about 3 inches above the cavitation plate. It seemed the intakes were well underwater.

I'll check on the hose in the morning. Weedwacker string sounds like a good idea.

Thanks, guys.

 

[kbait]

Probably not deep enough. Waterpump impeller must be submerged to begin pumping. Waterpump is not self-priming. Water level in bucket needs to be 3"+ deeper than lower unit mounting bolts.

 

[flyingscott]

Water needs to be higher at least 3" above where the lower unit splits and the water pump housing is.

 

[docksider]

I substituted a garbage can and got the water level up a few more inches, and it worked like a charm. Nice strong stream. Thanks for saving me the time and money of a needless repair, and letting me get the boat to the lake much sooner. PS- I also shot some compressed air through the tell-tale hose first, just to be sure and to have done that simple step. All was good. Thanks again, everyone!