Yanmar 155 trouble starting

[Ashton1012-HT]

Hello everyone!

I was recently given a Yanmar 155 for free. I haven’t had much time to tinker with it, but in the hour or so I spent the other day I ran into some troubles.

I’ll start by saying this is the first tractor I have ever owned. I am pretty capable of figuring things out on my vehicles and small engines, but this is also my first diesel project. I got it from a neighbor who’s dad owned it before he passed away, the tractor has not ran in 15 years but they have no idea what is wrong with it.

The problem I’m having is the starter does not seem to engage. I am not sure if the ignition switch is broken, or stuck on, or what. I do not have a key but when I connect the battery, a little smoking occurs from the engine. Doing some reading I believe this is due to a cold start feature. I cannot get the starter to turn over with the ignition switch so I think I will have to replace that.

When I jump the starter it engages no problem, I can hear the starter spinning, but it does not engage with anything in the engine. It just freely spins. Possibly a bad starter?

I was told he 4 wheel drive does not work. That is a project I’ll look more into after I get the old beast working. If this is a common issue that others have dealt with, how is it resolved?

I’m open to any and all advice. Like I said I’m a rookie when it comes to this stuff, so help point me in the right direction.

Thank you!!

 

[winston-HT]

Sounds like multiple problems. I would disconnect the battery ground cable where it attaches to frame and clean real well to start with. I would pull the starter and bench test it to see what is happening with drive gear.

This is the thermostart element. https://www.hoyetractor.com/PROD/TS-1.htm Is your smoking coming from the intake manifold area?

No doubt you have wiring or switch problems if smoking occurs when battery is hooked up. Common sense with voltmeter may be the answer.

<LINK_TEXT text="https://app.box.co...zravu7q7wsducjk/file/752082564948</LINK_TEXT>
<LINK_TEXT text="https://app.box.co...zravu7q7wsducjk/file/651208602127</LINK_TEXT>
<LINK_TEXT text="https://app.box.co...zravu7q7wsducjk/file/651205147896</LINK_TEXT>

 

[Chainsaw-HT]

Ditto to everything Winston said.

Sound like the bendix isn't kicking out out on the starter. Thats the little gear in the nose cone of the starter. You might be able to pop the starter apart and just give it a good cleaning, bendix solenoids like to hang up. With 15 year sitting I have no doubt it has corroded inside and is frozen in place.

I cheap remote start button is a great diagnostic tool when dealing with multiple electrical issues piled on top of one another, help you to work on ONE issue at a time.

 

[Ashton1012-HT]

Thanks for the replies guys! On Monday I’ll make another attempt to get it from the neighbors house. I had a bit of a hiccup- I intended on towing it home but the rear left (when your seating in the seat) wheel is locked up. Won’t spin at all. The neighbors don’t remember anything about it unfortunately, so I’m really just doing trial and error until I figure out clues. On Monday I’m bringing some come alongs and my trailer and will load it up. Any ideas what would be causing that wheel to lock up?

 

[winston-HT]

My first guess would be the brake is locked on that wheel. Make sure #5 is moving back and forth when depressing and releasing left pedal. <ATTACHMENT filename="2021-11-07-045927.jpg" index="0"><s>[attachment=0]</s>2021-11-07-045927.jpg<e>[/attachment]</e></ATTACHMENT>

 

[Ashton1012-HT]

Well I had some time to work yesterday. I got the starter off and bendix freed up just by taking off the starter. Confirmed my thermostart works, and fuel is getting to the intake. Will not start though. I have not changed out the old fuel though, I’m hoping it won’t start because the diesel is 15 years old. I’ll get it changed today and with any luck, she will fire up <E></E>

 

[Ashton1012-HT]

As far as the brake goes- #5 is not moving. That will be my next project after I get the engine started.
I ordered a new fuel filter, oil filter, pin for the gear shifter, and will order an air filter. I’m a little confused- some of these tractors have a canister style air filter, mine is just circular about 6” diameter and 1.5” deep. I’m missing the lid for the housing. Why did some tractors come with a different style ?

 

[Ashton1012-HT]

No luck with the fresh diesel fuel. Primed the line with some sea foam, turned it over for probably 10 minutes. Just doesn’t want to fire up. Any ideas?

 

[winston-HT]

Did you follow this bleeding procedure? when you say your are getting fuel to the intake, does that mean it is coming out of the line at the injectors? https://www.hoyetractor.com/FuelFilterVideo.htm

Can't tell you why but can tell you year models had changes on your model with air filters.

 

[Ashton1012-HT]

Thanks for the video, that is very helpful. I thought I was bleeding correctly but I guess not.
Before I lost daylight I went out and attempted to bleed properly- no luck. There does not seem to be enough pressure to push fuel up to the third bleeder screw. When I disconnect the fuel hose from the filter housing, fuel flows freely. When I reconnect, fuel can’t push up the hose to that next bleeder screw. I suspect the very dirty fuel filter is preventing optimum flow, so today I will attempt to bleed it without the fuel filter in place. The new one will not be here for another 10 days :/

 

[Ashton1012-HT]

It was coming from the line at the injectors, but not the amount needed. After watching a few other videos I now see I wasn’t getting nearly the flow other people show on videos. If I successfully bleed the system and still have no success, I’ll check the flow from the injectors themselves and see what kind of spray pattern I’m getting.

 

[Ashton1012-HT]

No success :/ fuel still does not flow freely up to the bleeder screw, even without fuel filter. What else could cause this problem? It’s a gravity fed system to that point, could it be I don’t have enough fuel in the tank/ “weight” to supply adequate pressure? I only put a gallon in there.

 

[winston-HT]

Might be possible some partially plugged passages around the bleed screw area. Do you have a compressor? Maybe try blowing through things to make sure all is open. No doubt more fuel in the tank might help to prime.

 

[Ashton1012-HT]

The sage continues!! I solved my bleeding problem, needed more fuel lol.

I currently have the injectors off. One of them is completely frozen up, the little center rod will not come out! The other one was easy to remove… soaking this one in wd40 for a bit and then I’ll try again

 

[Ashton1012-HT]

No success after soaking the part overnight. That center piece is frozen solid! Does not want to come out… I ordered new injectors, 40$ on Amazon for 6 of them. I’ll have some backups now. Hopefully this solves my problem and I’ll hear this engine run next week.

 

[Ashton1012-HT]

Another update- some unfortunate news!

I pulled the transmission dipstick- dry as a bone. Pull the drain plug, water…. About half a gallon. Maybe 2 oz of oil at the end of the water coming out. Without seeing inside the transmission, I can only assume it’s pretty rusty in there. Good news is, the water that came out was very clean and clear. So some hope the transmission isn’t rusted to bits? I guess we will see… first things first, get the engine running.

 

[Ashton1012-HT]

New injectors arrived. Unfortunately, still no luck starting the tractor. I think a pressure test is in order to find out if I’m dumping money into a hopeless engine.

I took the exhaust off to see if she’d start without it, and found it to be horribly clogged! Cleaned all the junk out, didn’t seem to help.

Is there something im missing? Some kind of safety feature that would prevent the tractor from starting?

 

[winston-HT]

Have you bled well and getting a good fuel flow to the injectors?

 

[Ashton1012-HT]

I seem to be. Having nothing to compare to, it’s hard to determine if the flow is “great” though. I ran out of daylight and won’t be home for three days, but when I get home I’ll walk through the bleeding procedure a few more times, make sure I can absolutely cross that off the list.

 

[winston-HT]

With throttle in wide open position there won't be a lot of flow but should be bubble free. Very important to start closest to fuel tank and work toward the injectors a step at a time.