YM1702D wants to die when returning to idle?

[Zoom233]

I'm drawing a blank as to what to call the issue so I'm not sure what to search for, so I'm not sure if this has been gone over before.

The problem I’m having is when I’m mowing or driving around or what ever when I lift off the throttle and the engine comes down to idle it doesn’t just settle down to a nice idle it dies or comes very close to it and then comes back up to a slightly ruff idle. That maybe also be a symptom, it does seem like it idles a bit ruff. Don’t know if that is normal or not as this is the first diesel I’ve had and first tractor. What might be the cause of this? The only thing I know might be wrong is I’m not sure how old the fuel is. I just got it and it’s freshly imported so it maybe be a couple weeks old and it could be months old. Not sure how important fresh fuel is to a diesel either, I know it can make a difference in a gas engine.

Thanks,
Bryan

 

[mark777]

Welcome Zoom,

IMHO fuel may not be the only issue. It sounds like a combination of insufficient air, at lower RPM, where the canister or filter are
clogged enough to deliver inadequate air. I would also check the fuel filter, filter glass and "O" ring and rubber fuel lines that may be painted over. The smallest crack can cause havoc when trying to diagnose the problem.

As long as your diesel fuel is clean and free of condensation...it can last for years.

Good Luck, Mark

 

[normde2001]

Assuming the 1702 has a hand throttle and a foot throttle like the 1700, if you are using the foot throttle and ease off , it will idle to what you have the hand throttle set at, which should be about 800 rpm, below that will stall.

 

[Zoom233]

I forgot to mention, I haven't checked it yet but the air filter is supposed to be new. I don't see any bubbles in the fuel filter sight bowl. I also don't see any gunk in the bottom of the bowl. When the hand throttle is shut all the way it idles about 700 rmp on the tach. Using which ever throttle, if the hand throttle is shut all the way and I am using the foot throttle and lift off it dies or almost dies, using just the hand throttle and shut it all the way same difference.

Do I just need to up the idle speed a bit to 800ish?

TIA,
Bryan

 

[normde2001]

"Do I just need to up the idle speed a bit to 800ish?"

The hand throttle is designed to shut the engine off when pushed all the way forward. There should be a detent, (notch), slightly before that point at the 800rpm idle speed.

 

[normde2001]

"Using which ever throttle, if the hand throttle is shut all the way and I am using the foot throttle and lift off it dies or almost dies, using just the hand throttle and shut it all the way same difference."

That's the way it's supposed to work. That's how you shut the engine off. If it does not, it needs to be adjusted.

 

[Zoom233]

I don't know that the hand throttle is supposed to shut mine off as there is a small pull lever/pull knob to kill it with, this is down on the bottom right of the dash. No I am not getting confused with the compression release, it is up top slightly left of center.

I haven't felt a detent but I'll go check and see if there might be one.

Thanks,
Bryan

 

[YanmarFever]

Zoom what state are you in?If you are in Oregon, bring it over I will have a look at it for you. I have had a few 1702s around here.Also the 1702 does have a kill switch that you pull on to stop the engine, located below the throtle lever.Ernie

 

[Zoom233]

Filled out my profile a bit and yes I am in Oregon but I had to have a friend borrow a trailer and use said trailer behind his truck to get my tractor home. So I guess I'm trying to say I doubt I'll be dropping by with it any time soon. Thanks for the offer though.

I think I might set the hand throttle at 800 and then just use the foot throttle and see if when I let up if it still wants to die. If it stays running no problem then my guess is the idle speed is just misadjusted and needs to be raised a bit.

I think I figured the idle was supposed to be pretty low as you always hear about bottom end power on a diesel.

Thanks,
Bryan

PS. I'm pretty new to having a tractor and this is my first diesel. Any tips? Stuff that's not always or rather imediatly obvious?

 

[normde2001]

"I think I might set the hand throttle at 800 and then just use the foot throttle and see if when I let up if it still wants to die. If it stays running no problem then my guess is the idle speed is just misadjusted and needs to be raised a bit."

There is no set idle speed. Normally you operate the tractor with the hand throttle and set the idle wherever you like it. The foot throttle is merely an added convenience that is only installed on a few Yanmars.