155d slow throttle response

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