1998 Mariner 200HP 2 Stroke Starting and Idling Issues

[superharmonix]

I have had this problem the last two times I took the boat out. It is a little sluggish to start cold, but always fires up and idles fine at the dock and on muffs. The motor always has fresh properly mixed fuel. (no oil pump)

After running at near WOT for 15-25 minutes, once I shut it down and fish for a few hours or longer, the motor will not fire. It cranks like normal but will not start. This is both while choking and without choking. Fresh fuel, primer bulb hard, fresh battery with tight connections and no corrosion. The first time this happened, I let it sit for a half hour or so and it still wouldn't fire. I got towed in, and a couple hours later at the dock, it started.

After that trip, I replaced the fuel line and primer bulb. This most recent trip, same scenario only this time after some time, I was finally able to get it started, but as soon as I put the throttle in neutral, it dies and will not idle. I am wondering if anyone has a similar motor with similar issues? If so, what is the fix? I really am not looking for an easy fix, as I want to know what is causing this issue so I can address it properly. Thanks in advance for any direction y'all can give.

 

[Dukedog]

efi or carb motor?.. i'd do a mechanical fuel pump kit first.. easy and cheap ta do...

 

[superharmonix]

efi or carb motor?.. i'd do a mechanical fuel pump kit first.. easy and cheap ta do...

It’s carbed. I appreciate your response and will check it out.

efi or carb motor?.. i'd do a mechanical fuel pump kit first.. easy and cheap ta do...

It’s carbed. I appreciate your response. I need to do that. The fact it starts fine after sitting for weeks, then while at the dock, then after running 15-20 miles or so after fishing with it off 2 or 3 hours it dowsn’t want to start or now idle is driving me nuts.

 

[Dukedog]

jus somethin' ta check it out.. a leaky (inside) mech pump won't bother a cold motor start and run.. will run jus fine off idle, wot.. starting and idle different story with a warm motor...

 

[superharmonix]

jus somethin' ta check it out.. a leaky (inside) mech pump won't bother a cold motor start and run.. will run jus fine off idle, wot.. starting and idle different story with a warm motor...

Much appreciated. I am going to order one and put it on.

jus somethin' ta check it out.. a leaky (inside) mech pump won't bother a cold motor start and run.. will run jus fine off idle, wot.. starting and idle different story with a warm motor...

much appreciated. I am going to order one and put it on. Not sure how okd the current pump is anyway so good time to change it! Thank you sir.

 

[dsiekman]

Check your spark. Mine used to be very temperamental. I replaced the stator (it was arcing to the block) and found a bad ground to an ignition module. Starts much easier and more consistently now.

 

[superharmonix]

Thanks y’all!

So far, I rebuilt the fuel pump. Old one was leaking slightly, and in the process of looking at things I found a slightly loose clamp on the outlet hose from the fuel/water seperator as well. Fixed both.
Started fine cold (albeit a bit sluggish), ran great at high speed, seemed to bog a bit at low speed. Stopped and fished, started motor a few times no problem.
...then today, hard to start. Finally started and after warm up ran fine. Then after awhile, motor would not start. Primed the bulb hard, still no start. Tried starting with the neutral throttle up, still nothing. Just keep turning over and not firing.

...eventually after an hour, I tilted the motor up a bit, and with the throttle advanced, was able to get it started. But- as soon as I back it off, it dies. It will not idle.
Tomorrow it will start fine and run, then I will run into the same issue. I checked the battery, and it is at 12.8 volts, so I know there is plenty of voltage to start the motor. The hard start and no idle (only in mid day) continues to evade.