1993 Johnson 70HP 2stroke: won't start when WARM

BobU

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So what's the "normal" or suggested way to start the engine when warm and you know the gas has boiled off? Do you turn it one click (on), then press in for a brief moment to prime it, then turn one more click (start)? If it doesn't start, then while still in start position HOLD it in until it starts? I never knew starting an engine could be so technical :)
 

jakedaawg

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I have been following this thread. Here is what I would do:

Follow one if the two lines coming off primer solenoid. Pull it off where it hooks in to the manifold. Squeeze bulb til firm. Have some one crank engine while pushing in key at same.time. verify you get fuel squinting out.

If good go boating. When you feel you have the right conditions for your hard start problem do this first.
1. Squeeze bulb til firm. Turn key. If it starts great. If not
2. Squeeze bulb. Lift up on fast idle lever til you feel a little resistance. Push key in while cranking. If it starts great. If not
3. Lift fast idle all the way. Crank key for no more than 10 - 15 seconds at a time. Do not push in on key. If it starts get a new tank or revisit your needle and seats. I am wondering if you have a tank that is overheating in the heat and forcing fuel past the needle and seat because it is not venting properly.
 

BobU

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My tank is nowhere near the engine, so tank is not overheating. I'm just trying to understand the proper use of the prime switch (pushed in). Like ReedMikel, I've heard different explanations as to how/when the prime position works. I get the impression that it may vary between some engines, otherwise why would marina mechanics vary in their advice? They probably have to know so many different manufs and models... At this point I'm so unsure of how it operates that I think I'll do the physical test that you suggested jakedaawg...
 

racerone

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With modern cars the sensors and computers " know it all " and the operator just needs to push a button.---Some older 2 strokes require the operator to learn how things work.---When you understand how things work it does become easier.
 

ReedMikel

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I can't wait to try to explain this warm start procedure (or lack of) to my wife so that when she has a girls weekend at the lake she doesn't end up stranded on the lake :). Too bad the boat engine manufacturers couldn't have simplified things. My Stihl chainsaw from about the same year is much easier to start...
 

jakedaawg

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I can't wait to try to explain this warm start procedure (or lack of) to my wife so that when she has a girls weekend at the lake she doesn't end up stranded on the lake :). Too bad the boat engine manufacturers couldn't have simplified things. My Stihl chainsaw from about the same year is much easier to start...

Wow. My still 360 and 880 are a bear to start. But once they do they cut....
 

ReedMikel

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I think I'll bring my chainsaw with me the next time I go out on boat. If I get pissed off ill just cut boat in half :)
 

Fed

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Does this motor have quickstart ReedMikel, what model is it?

I'm wondering if manually advancing the timing with the fast idle lever added to the quickstart electronic advancing is making it difficult.

Here's my routine fwiw.

Cold start. Pump primer bulb, raise fast idle lever and crank over while pushing key in.
Warm start. Raise fast idle lever and crank over, if it doesn't start within a couple of seconds I then push the key in.
Hot start. Simply crank it over.

Around 30 minutes of sitting seems to be the tricky warm zone.
 

jakedaawg

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I can't wait to try to explain this warm start procedure (or lack of) to my wife so that when she has a girls weekend at the lake she doesn't end up stranded on the lake :). Too bad the boat engine manufacturers couldn't have simplified things. My Stihl chainsaw from about the same year is much easier to start...

My girl made me buy her a four stroke. Solved all the girls weekend problems.

She even has the girls Cook me dinner. Then again, I got my four stroke at Floorplan price.
 

ondarvr

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There is no exact way or method to start every older two stroke, they seem to all have slight preferences in just what needs to be done, all these suggestions are just that, suggestions. If you understand what's going on you can at least tweak your methods until you get it just right for how your motor needs to be started.

There is no confusion on how the primer valve works, it's been described here accurately several times, if someone tells you something different they don't know what they're talking about. Without turning the key try to push it in, it either won't go in or won't click, turn it to the on position and push it in, you will hear a click, that's the solenoid. when you hear the click you know it opened. Again, it's not a pump, the only pressure supplied is from the fuel pump or the squeeze bulb, once you push the key in the fuel will squirt in, then slow to a stop, it won't squirt more in after that, although if you have the hose pulled off you may see a little trickle come out.

If you squeeze the bulb while holding the key in fuel will be pumped into the motor, it will also be pumped in when the motor is cranking, one of those two things need to take place for it to supply fuel.
 

ReedMikel

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Does this motor have quickstart ReedMikel, what model is it?

I'm wondering if manually advancing the timing with the fast idle lever added to the quickstart electronic advancing is making it difficult.

Here's my routine fwiw.

Cold start. Pump primer bulb, raise fast idle lever and crank over while pushing key in.
Warm start. Raise fast idle lever and crank over, if it doesn't start within a couple of seconds I then push the key in.
Hot start. Simply crank it over.

Around 30 minutes of sitting seems to be the tricky warm zone.

I forget the exact model (it's at our lake house), but it's a 1993 70hp 3 cyl with the oil injection system. I agree, after about 30 minutes of the motor being turned off, "heat soak" becomes an issue. Last weekend I did have the typical hard start after motor had been off for 45 mins, so I tried pressing the key in multiple times while it was in the ON position, then turned key to the crank position and it started pretty quickly. I'm going to pull the lines off the primer solenoid as a forum user suggested and see exactly how this solenoid releases gas. I want to test whether it releases fuel constantly when key is held in, or just one squirt? Will post results next week...
 

jakedaawg

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If it's not cranking over the solenoid will only release what pressure is in the system. Maybe a squirter, maybe nothing. The pump needs to be making pressure for it to work.
 

Fed

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I'd question the volume of fuel 'stored' in the system after using the primer bulb and how long it remains under pressure before leaking down.
Very little for a very short time.
 

jakedaawg

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I'd question the volume of fuel 'stored' in the system after using the primer bulb and how long it remains under pressure before leaking down.
Very little for a very short time.

Agreed fed. I am mostly thinking of these new EPA tanks that seem about ready to explode. I wonder if the could build pressure enough to make the primer work with out the engine turning which would then make me look like a fool. It's easy enough for me to look like one. I don't need the EPA'S help.
 

Fed

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Good point jake, I never gave a thought to EPA tanks we don't use them down here.
EPA tanks will have a huge effect on people who use the so called '8 second key push' before cranking over. :eek:
 
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