Governor adjustment

guyd · Feb 17, 2009

Had a search- cant find the answer I need... ;(

My 1510 (18Hp) smokes a lot. Local (retired) diesel bloke said to adjust pump fuel adjuster in a bit.

Located said adjuster - the cap nut covers it on the front of the gov block.

Now the problem comes:- the 'big' thread (1/2") seems to adjust the throttle 'response' - ie how quickly the engine revs up. What does the 1/8" diameter bar (with two locknuts) do on the end of it? Said bar seems to jiggle in and out if you floor the throttle....

MJPetersen · Feb 18, 2009

It is my opinion that the fuel rack is not the problem. If the smoke is black when it is running high idle then there is excess fuel, blue is oil, and white is incomplete combustion/water. However even the black smoke most likely is not caused by the pump adjustment. It could be injectors that are dribbling or have too low of a trip pressure, it could be an air restriction (air filter, or plugged intake tube). I would eliminate those kinds of things before adjusting the pump.

The pumps on our tractors are a pretty simple construction. There is not so much that can go out of adjustment. I think that probably your problem lies elsewhere.

Mike

guyd · Feb 18, 2009

Thats what I thought - so the injectors were re-furbished at the (only) local diesel repair shop - at a cost of 150 UK pounds (213USD at todays rate) - made little difference. It did improve though - just not much.

SOME of the smoke is blue - but not a lot. The issue is black / grey smoke when under strong load - which implies fuel pump adjustment - hence the original question. Under no load - there is no smoke - at any RPM - only under load - the greater the load - the greater the smoke. After some fiddling - I have reduced the smoke - but the governor response is now very slow (ie / eg it almost stalls when the log splitter reaches the end of its travel - unless the 'throttle' is set to mid to high revs)

MJPetersen · Feb 19, 2009

Well you have to admit that I did not know from your post that you had already had the injectors worked over.

Do you have a manual for the YM 186? It suggests that excessive black smoke is caused by 1) improper injection timing 2) excessive injection rate 3) faulty nozzle spray.

I have the manual if I can be of any help by sending a page or two or three.

The fuel volume is controlled by an adjustment inside the pump. There is an adjustment plate and screws which the manual says "DO NOT LOOSEN" or else they will have to be adjusted for "injection volume by a pump tester."

You might try taking off the exhaust manifold and running the tractor to see if the problem is associated with only one cylinder or if it is on all three. (It will be loud, so not at midnight--or I might hear it from here.)

Mike

guyd · Feb 19, 2009

Thanks MJP - Ill pm you my email address. I didnt mean to come across rude - sorry.

There are two adjustments that I can see - under the cap nut is a large diameter fine threaded body, held in place with a locknut. This appears to control the throttle 'response'. A half turn either way makes a large difference to the response.There is inside that, a tiny (4mm?) threaded bar with a pair of nuts on the end. This was set almost flush (ie the outer nut face aligned with the end of the small shaft). This jiggles a bit when the engine revs hard. Adjusting in or out made no dicernable difference.

If this doesnt work - Ill take it to an expert - but theres nothing local - what should i be looking for , to find someone who would know where to look? Car mechanics would just scratch their heads, ditto truck mechanics - boat engine people? (yanmar make a load of marine engines I suppose)?

MJPetersen · Feb 19, 2009

Ok I sent to you a few pages from the manual. I suspect that marine engine supply would be your best bet. Yanmar makes LOTS of engines in marine applicaitons. I do not know if the procedures are the same, but why reinvent the wheel.

You did not come across as rude at all, I was just embarrassed that I had assumed something, when you are obviously are much more mechanically inclined than I thought.

You did check that some bird or mouse has not nested in your air passages though right? I have also had engine oil that was being sucked into the intake blow bluish/black/grey smoke. I wonder if the intake seals on the valves could be passing a bit of oil?

I would certainly like to know what you find out, so that I can file it away for future reference.

Best wishes.
Mike

Inspector507 · Feb 19, 2009

guyd said:
My 1510 (18Hp) smokes a lot.

guyd said:
The issue is black / grey smoke when under strong load - which implies fuel pump adjustment - hence the original question. Under no load - there is no smoke - at any RPM - only under load - the greater the load - the greater the smoke.

How long does the smoking continue? With the YM1700 I had, it would always puff black smoke under heavy, until it settled itself out. Then it would quit. Does yours continue smoking? Or is it too much load?

guyd · Feb 22, 2009

Going up a long hill - for example - leaves a continuous trail of impenetrable smoke... I have the manual from Mike (thanks) which I shall act on when I have three nanoseconds spare, during daylight...

1130Lilshive · Oct 1, 2017

MJPetersen said:
Well you have to admit that I did not know from your post that you had already had the injectors worked over.

Do you have a manual for the YM 186? It suggests that excessive black smoke is caused by 1) improper injection timing 2) excessive injection rate 3) faulty nozzle spray.

I have the manual if I can be of any help by sending a page or two or three.

The fuel volume is controlled by an adjustment inside the pump. There is an adjustment plate and screws which the manual says "DO NOT LOOSEN" or else they will have to be adjusted for "injection volume by a pump tester."

You might try taking off the exhaust manifold and running the tractor to see if the problem is associated with only one cylinder or if it is on all three. (It will be loud, so not at midnight--or I might hear it from here.)

Mike

I know this thread is old and forgotten but I need someone to elaborate on this fuel pump adjustment plate the one that says do not loosen. Any help is greatly appreciated.