155d slow throttle response

clemsonfor · Jun 16, 2017

man that is show room condidtion

chevy791979 · Jun 16, 2017

clemsonfor said:
man that is show room condidtion

I know right? I've known the original owners grandson door a long time and he bought it new in 1979. Dug out a basement with it and it has been babied ever sense. And has never once sat outside. Lol. Original tires and hoses and they look brand new.

deepNdirt · Jun 16, 2017

Well theres the problem right there, It's never been broke in correctly, A tractor needs to be in some mud occasionally be over revved, and overloaded from time to time. This is how it knows it's a tractor and not a powder puff.
Lol.

chevy791979 · Jun 16, 2017

Very true. I almost feel bad for it because I'll use it like a tractor. I'll do my best to keep it nice but trust me it will be worked like a dog.

California · Jun 16, 2017

chevy791979 said:
I'll use it like a tractor. I'll do my best to keep it nice but trust me it will be worked like a dog.

You can't hurt it. Appearance, sure, but not the mechanicals.

HoyeTractor · Jun 16, 2017

I almost feel bad for it because I'll use it like a tractor. I'll do my best to keep it nice but trust me it will be worked like a dog.

Nice tractor! Just be sure to watch your antifreeze mixture. That tractor does not have a water pump so the coolant ratio is critical. Installing a mechanical temp gauge would also be a really good idea.

chevy791979 · Jun 16, 2017

Cool. Any pointers on thread pitch and fittings for the sensing side of the mechanical gauge?

clemsonfor · Jun 16, 2017

I will have to check my notes but I was thinking it's metric 6? That's probably totally wrong but I know a few guys like California and Winston have it on the tip of their tounge. I have it in my notes on my phone. If they don't chime in here in a second I can check them and give it to you.

California · Jun 17, 2017

Hardly. I posted details long ago when I researched for my own use, now can't remember, or find the post.

The oil fitting is the same as nearly all Japanese cars, anything from Autozone works. Water however ...... ???

winston1 · Jun 17, 2017

The oil pressure threads on a Yanmar are 1/8bpt. The temperature threads are m16-1.5.

deepNdirt · Jun 17, 2017

When I replaced mine it came with a couple fittings to choose from. One was the correct one.

clemsonfor · Jun 17, 2017

There you go!!

chevy791979 · Jun 19, 2017

I will be adding a gauge but I've had a few 2 cylinder John Deere tractors that were thermal cycle and they never got over 170 even pulling a 3 bottom plow for almost 1miles rounds.

chevy791979 · Jun 19, 2017

I understand that these cooling systems hold far less coolant but they are also for less engine size.

rScotty · Jul 1, 2017

chevy791979 said:
New member here. Just got a sweet deal on a 155d with 280 hours on it and was a 1 owner. Runs good but the throttle response is slow. Any thoughts?

Yes, my YM165 (nearly identical) tractor did the same thing one spring. The fix was to replace the fuel filter element. It didn't look clogged or dirty, but something must have changed because when I changed the element it responded to the throttle like new again.

Pay attention to that coolant. 50% antifreeze is max for a thermosiphon system. It's all in the owner's manual.

As far as I know, there are no NPT fluid fittings on the basic Yanmar engine and dashboard gauge setup. Some people have reported that they found some tapered connections that were using the Metric tapered pipe spec, but that wasn't the case in mine. All my OEM fittings that used a tapered thread were BPT (British Pipe Thread), just as all of the straight thread bolted connections were Metric spec.

However, Yanmar sourced the loader from Canada back when we bought the YM165D new. All of the loader connections were a fine and mysterious blend of metric, US, and NPT.
luck,
rScotty

clemsonfor · Jul 1, 2017

I think that iF the fuel had growth in it. Like mold or algae, you may not be able to see it, but that microscopic growth may be so fine that it's clogging the filter yet you can't see it like if it were a bunch of black gunk.

chevy791979 · Jul 6, 2017

winston1 said:
The oil pressure threads on a Yanmar are 1/8bpt. The temperature threads are m16-1.5.

Are you eliminating the idiot light in place of the gauge then?

rScotty · Jul 6, 2017

chevy791979 said:
Are you eliminating the idiot light in place of the gauge then?

I kept both light & gauge. Doing so is just a few extra fittings from the hardware store.
Thinking back to the gauge installation on our YM165D, It all started when I couldn't resist that cheap triple gauge set with volts, oil, and temperature in a package with all the fittings for under twenty bucks! That was 30 years ago when twenty bucks was almost real money.
But I never did like that nylon oil pressure capillary tube that came with the set. It seemed to be a possible source of leaks. Besides, who ever heard of plastic parts on a tractor? Of course since that time the nylon capillary tube has been proven in many applications. So maybe times have changed, or maybe I just like to worry... but if and when I do it again I'll try to find an electronic pressure gauge.
an old-timer, rScotty