Any diesel wrenchheads?

[mael]

Diesel Wrenchheads? Did I really say that? I am becoming American!

Sorry to sully the board with this, but I need some help and I am frustrated for answers by asking in the places I have asked so far.

The problem is a small diesel engine I'm trying to get running. It's a Yanmar, it's about 400cc, single cylinder, and there's a problem with the injector pump.

I've not worked on diesels before and I made the mistake of removing the injector pump when I decided to try to clean it.

The pump wasn't working when I cranked it. Fuel was getting in, but it wasn't pumping out. Eventually I decided to remove the unit. But it won't slide out as it's connected to a governer by an arm, which must be removed in order to slide the pump unit out. I hadn't realized at that time how critical the setting on the governer was, and now I discover apart from a general lack of info about diy fixes of injector pumps, the setting of the pump is something normally left to trained professionals with special equipment (that I haven't got).

I took an engine cover off to get at the arm-linkage, and had that side of the engine stripped-down on a nice sunny day. Then in the afternoon the weather turned and I ended up scurrying about trying to cover everything and get the tools inside. Then it rained and we had high winds for two days and then I noticed the governer slide had fallen out of the plastic bag I had put all the parts in to stop them from getting waterlogged. Inside the governer slide there is a small spring attached to a valve like a needle valve. (Of all the pieces to fall out, this was the most difficult to replace). Well I found the slide, but the spring and needle valve is still missing, and the chances of finding that piece seem very slim.

Commonsense tells me I've got a useless diesel engine which would be best to scrap asap. But the wild side of me says I should try to fix it.

I had the engine splutter a few times with carb cleaner down the air manifold, so basically it's a goer apart from the injection side of things.

So I would appreciate some advice from people who understand diesel engines.

I know the injector pump delivers a precisely timed amount of fuel to the injector, and that the governer serves to adjust the dose of fuel. However I don't know much more than that at the moment.

Theoretically I can fix it by manually adjusting the linkage on the governer, but it could take one go or it might take a hundred tries. As it is necessary to drain the oil and remove the engine cover each time an adjustment is made, it seems somewhat awkward to attempt to get the position right using this method... especially with my limited knowledge of diesels, which means my guesses might not be very close. ... and this is assuming I can either make the governer valve work, or make it so the governer valve is bypassed.

I am aware I might make something like a semi-diesel by jury-rigging a heater to mix something containing diesel. How about a small carb running a mix of diesel and gasoline fixed to the inlet manifold?

Well, I don't see much need for me to demonstrate my ignorance much more in this post, so can I throw this problem out to the members here and ask you to point me in the right direction?

[mael]

Just a small update.

There are no parts missing now. Now all I need to do is get it all cleaned and make sure it works. Then there's that "little" matter of adjusting it correctly.

Trouble is I don't like giving up, so I'll be trying to fix it until I am either successful or until I break some vital part I can't replace.

Maybe I'll have some good weather tomorrow so I can spend some time getting things in order.

And I'm very much in need of hints and advice for adjusting the injection pump. If I understand how it is supposed to work, and also understand the reasons behind why it works as it does, then I think I stand a good chance of getting it close enough in order to start it, and then if it starts I should be able to figure out which direction I need to turn screws.

(Crazy huh)!

[mael]

I cleaned the bits, put them together, bolted the injection pump on the engine.

Then I checked it was pumping by cranking it. Then I bled the system on the pump output and again at the injector.

Then finally I set it so the needle valve was tight when the centrifugal rod was fully extended, cranked it a few times and it went.

I held onto the valve-lifter until I was sure it wasn't going to run away. I was absolutely amazed that the throttle control was perfectly adjusted.

It idles even at a couple of hundred rpm - if I let the speed control cable slacken enough. I don't know what top end rpm is, but it sounds about right. Maybe 3,000rpm at the moment.



The first time I cranked it with the intention of starting it it didn't even have any oil in it, and the engine cover was tacked on by three bolts instead of the twelve it needs. Well as it started, I soon stopped it using the valve lifter, put the oil in it, tightened up a few connections and put the rest of the bolts in and then cranked it and listened to the music.



It needs a few things done to it because it hasn't been used for a decade or more. It's pretty rusty and the cables are grunged-up and unwilling to move. A couple of bolts got turned and had the heads snapped off, but I'll work on that and thse problems seem minor.



I haven't put it in any of the six gears yet, and I haven't fiddled with anything else whilst it was running for fear it'll take off and smash into my car which is a few metres in front of it ... I haven't ever used one of these Yanmar (350kg) rototillers before and I'm a bit apprehensive at the moment.

Well it looks like I've figured it out, so this thread should die.

I hope I might have encouraged others to have a go with their injection pumps on a diesel.

Well - That's it I suppose.

[SeaMonkey]

Well done Mael! Just goes to show us all that where
there is a will there is a way.

Diesels are fascinating. I had a VW Rabbit diesel several
years ago. It was given to me by a friend and had some
problems. I worked on it a bit and got it going and let
my son use it for school. That was rather a mistake.

The VW engines just weren't built sturdily enough.

Is your Yanmar still going?