2610D Injector pump timing

   / 2610D Injector pump timing #1  

rock2610D

Silver Member
Joined
Jul 4, 2007
Messages
163
Location
Cheyenne WY
Tractor
2610D
Trying to time my tractor correctly. With clear hose attached to #1 injector line I find that my pump timing must be off.

There are a total of 6 lines/marks on my crank pully. 3 of the lines/marks on my pully have #1,#2, and #3 right next to them. The other 3 lines are about 1 inch ahead of their corrisponding cylinder lines/marks, as engine is rotated clockwise.

When my fuel stops rising in the clear hose my tick mark is right between the mark that says #1 and the other unknown mark.

Which one is the mark I need to hit? The service manual I have states "TIMING MARKS". The photo is too dark to see.

The reason I am asking is because the tractor is VERY hard to start in cold weather IE below 60 deg F.
 
   / 2610D Injector pump timing #2  
Rock,

I'm not familiar with all of the marks you've indicated for fuel pump timing.

I'm only aware of the two - Camshaft and Crank for #1 piston at TDC. Since you have the benefit of additional marks on your setup, can you watch each of the cam lobes that lift your injector pump rollers (with the timing case cover off of course)??

I would think that after every third revolution the cam lobe angle should be at the 12 o'clock position indicating the correct timing for that cylinder. And I'm not aware of anyway to actually change the pump timing... but changing the cracking pressures by adding or removing pump shims at the base of your pump.

Back to the original problem. I think a tractor that has difficulty starting at or below 60° is often a compression problem and not really pump timing.

I hope I'm wrong.

Mark
 
   / 2610D Injector pump timing
  • Thread Starter
#3  
I agree it could be a compression problem, most of all because I live at 8000 feet of elevation.

I am just wanting the timing to be right on to help minimize the elevation issue. Basically, my air pressure is right around 11 psi as apposed to the 14.7 psi at sea level. Thats 3.7 psi lost due to elevation. 3.7 psi x 7.8 in^2 bore = 29 pounds lost. Basically, its like this. at sea level 14.7 X 21(COMP RATIO) = approx 310 psi compression at TDC.

I however only have 11X21=231 psi. at TDC!!!

My tractor needs to be in tip to shape to function at my elevation. That is why I want my timing dead on.

A turbo is in the works to compensate while running but I have no idea how to increase pressure while cranking!!
 
   / 2610D Injector pump timing #4  
60 deg below 0 :eek: I wouldn't be outside in that weather. I would also look at the oil weight etc,.I don't know of a Dino oil that will even pour that temp.

I would be hard to start in that kind of weather:D
 
   / 2610D Injector pump timing #5  
lol Kenmac, I think rock2610d meant below 60F.. :D

Rock, do you give it plent of throttle, and preheat with compression release? I believe Mark777 will be able to give the most advice on timing, but i never hear/read about others setting timing on these older yanmars... If anyone knows about that, please write in! I'd like to advance the timing on one of my yanmars to increase top-end HP capabilities... :)
 
   / 2610D Injector pump timing #6  
Ok, my bad I re-read his post:p . I'm kinda tired & shouldn't be posting . Been up since 6am cutting very large trees & just came in
 
   / 2610D Injector pump timing #8  
rock2610D said:
... but I have no idea how to increase pressure while cranking!!
When I bought my Yanmar it had a weak used battery and nasty old un-volatile fuel. And the ThermoStart was dead. In the middle of winter. Until I sorted out the fuel problem what I did to help start it was to set the 2-10-50 amp charger on the hood and overcharge it, 50 amps for a minute or so, then 10 amps for a few minutes, then a 50 amp boost while I cranked the starter. It spun like mad.:D You might try a similar approach, or get one of those 650 amp portable boosters to use during power outages.

I would be surprised if it is a timing problem. They can't get out of time unless someone tinkered with it. Where did you buy it?
 
   / 2610D Injector pump timing
  • Thread Starter
#9  
According to my 336 manual you can adjust the point at which the injectors pop into the pre combustion chamber/cylinder. Adding shims will make them pop later and subtracting shims earlier.

I just do not know which mark to hit. The one that says #1 next to it or the other unknown one. At this point I spent the day experimenting.. I took out all the shims (3 total) and put back togather. All that did was move the pointer location a couple of degrees more advanced. There is NOWAY of hitting unknown line/mark with out grinding the face of the pump. WILL NOT DO THAT!!

Next I took a 1/16" intake gasket and added the 3 shims and pointer was now directly on the line that says #1. Tractor seems to start fine and it runs just as well as the previous setting. Its summer so all I can do now is wait for a 60 degree day.

I am also going to try hooking up the thermistor heater to the crank side of the ignition switch too. Plus I have found that NOT using the decompression lever works better. Because I have put the largest strongest battery I could find (1200 CCA) in the tractor and cleaned posts and ground points the tractor spins over nicely. Using the decompression lever only allows more cold air to get in the cylinders. I spin the motor over for about 10 seconds with fuel OFF to help heat cylinders (IE cold fuel not being injected) and then engage the throttle.

Since I put new injectors in its easy to check compression. That is on the list too.
 
   / 2610D Injector pump timing
  • Thread Starter
#10  
Bought it from a dealer in Louisiana, who got it from an estate sale. Tractor has 1320 hours on it and I was told it started great in LA.. A friend of mine picked up the tractor for me and before he delivered it he used it a couple of times in Louisiana and he said it started great! Its warmer and air is denser there, go figure.

I am going to IL next November so I will probably tow the tractor there and see how it starts there in cold weather with dense air.
 
 
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