Priming pump

[braver]

Our engine, Johnson 88hp (of 1996), stopped when we ran out of gas. After we added fuel, it wouldn't' run at low speeds.

Mechanics first diagnosed a carburetor leak and rebuilt it. Then they said that was not it, that the culprit was the priming pump -- which is activated for a cold start, when you push the key in. Supposedly a piece inside broke off/melted -- looked like a white plastic ring, supposedly related to the thin plastic piston, and it was constantly engaging, flooding the carb.

They charged us an astronomical amount. I wonder, (1) is it possible/professional to diagnose the priming pump first? (2) if the carb was flooding because of the pump, is it still necessary to rebuild the carb after it has been leaking -- even though the pump is fixed? (In our case they did, but I suspect if they'd identify the pump as the problem first, it would have been unnecessary to tinker with the carb.) )

They've billed us 7.5 hours. The boat stayed in the water, they say they've done the work there! Is it reasonable? If not, how can I challenge it, given the worklog? I don't think it makes sense to pay $1,000 every time engine trouble takes us to mechanics, so that we would subsidize their education in Johnson engines...

BTW, there's no posts on the priming pump! Is it such a rare problem?...

 

[ob]

Re: Priming pump

I assume the engine runs fine now.The primer solenoid valve I believe is what you are describing.It gets its fuel source from the fuel hose primer bulb once it's been pumped up firm.By pushing in on the key ,the electric solenoid of the primer valve is avtivated causing it to open and allow fuel to bypass the carburetors for cold startup.Not a pump but rather a valve.

Otherwise,I can't speak for what the mechanics should or should not have done to rectify your initial issue.You'll have to take that up with them.

 

[DHPMARINE]

Re: Priming pump

If I were working on your motor,and the carbs were flooding,I would also rebuild the carbs first.It is then obvious the problem lies elsewhere.Sort of like having to do the waterpump 1st to diagnose an overheat problem.

I'm not sure when (back in the 80') they started using the primer solenoid,but I've only seen a couple fail and flood an engine.But it does happen.

It's hard to address another shop's repair time.7.5 hours seems high,but I would never try this repair in the water.So that would take longer. Also they had to do two carbs,then further diagnose to find the primer problem.

 

[rickdb1boat]

Re: Priming pump

Seems pretty high to me. Even being in the water....

 

[DHPMARINE]

Re: Priming pump

These days the hours seem to mount up faster than they used to.I think part of it is knowing we are charging/paying $1.00 a minute (at $60.00 per) and more as the rate goes up.

I figured 1.0 hours to 1.5 hours for carb removal.

1.5 to 2.0 hours to reinstall.With adjustments.

Add rebuild (bench) time,

Add diagnose primer time and replace time,and the hours add up.

DHP

 

[braver]

Re: Priming pump

Yes, now it works OK. I still have to get a good feel of how to start it -- what works is, I open the throttle, and actually push the key before another attempt if it doesn't start right away. Do you guys use the primer valve during start-up? Also -- do you have to put the throttle lever back to neutral and then open again in between failed start attemts, and if so, where in that sequence do you do the squirt with push-key?

 

[rickdb1boat]

Re: Priming pump

Cold start:

Pump the fuel primer bulb up until firm
Raise the fast idle lever about one third up
Push and hold the key in for a count of 5
Start the engine while continuing to hold the key in
When it starts, release the key and throttle down to appropriate idle to keep it going. You may have to bump the key in a couple of times to keep it going until it smooths out...If it dies, repeat procedure....

And the primers do go out. Mostly from leaking at the cap. Just replaced mine this year for a failed internal problem....