governer

[rccktmn2-HT]

I have a YM1500 which overheated and stuck a valve, after the valve stuck the pushrod fell down between the injector pump and the cam taking out the pump. So long story short I have replaced the injector pump pushrod, valve, had head machined, etc. and now I'm at the point of trying to get it started again. I have everything back on, primed the pump, and cranked it over and noticed I was not getting a lot of smoke, so I took the inspection cover off the governer and above the inj pump and noticed that when the throttle is pulled all the way back the rod from the gov was not moving the slide all the way back on the pump therefore not allowing enough fuel out of the pump, so I moved the rod and tightened the screw at the governer which allowed the slide to move all the way back and now I'm getting allot of smoke, white smoke but it's smoke, but still no fire, the engine turns over just fine, we have smoke which tells me we have enough fuel but no fire. Any advice would be appreciated, I would also like to know what the torque spec is for the rod between the governer and the pump, if I leave it loose the pump doesn't let enough fuel out but if I tighten it then it seems it won't shut the fuel off, it does have a slot in the governer end. Any information would be great.

 

[winston-HT]

I am not sure I understand what the "rod" is? Are you talking about #17? <LINK_TEXT text="http://www.hoyetra...e=HTE&amp;Category_Code=YM1500GOV</LINK_TEXT> If so, it looks like a shoulder bolt on the governor end and a bushing and pin on the pump end. Both are designed to allow the governor arm to pivot and move freely. The governor rod arm hole should go over the shoulder bolt and be free to move when the shoulder bolt is tightened. Yanmars discription of item #22 is "clamp". Looks like a bushing to me. Just what is it?

 

[rccktmn2-HT]

Yep #17 would be the rod, the problem that I am having is when I tighten down the rod it does not move in the slot on the governer end, but when I leave it loose to allow it to move then it does not move the slide on the pump enough to allow enough fuel to come out to start the engine.

 

[winston-HT]

After looking at another drawing I see there is a spacer (I think #21 on the drawing) that should allow the arm to move in the slot when the locknut #24 is tightened. Do you have a spacer on yours? Here is a much plainer drawing of a 336. I know it may be different from yours, but I believe the linkage connections are very close. If you go to figure 14 you can see the parts I am talking about even though the reference numbers are different. <LINK_TEXT text="http://downloads.p...Parts Manuals/Yanmar/Y00T2140.pdf</LINK_TEXT>

 

[littleguy-HT]

Yes there should be a spacer so the little bolt will tighten down but let the rod slide in the slot. I cut the end off a small ring termal (wire termal) and used that. Also getting it to tighten down in the right spot on the slot is inportant also. If it's not in the right spot the governor will not respond as needed under a load. I learned this from experience last year when I rebuilt my YM 1500. Take a piece of cardboard, or something similar and place under the linkage so in case you drop the bolt, nut or space it will not go down in the engine. You may have to adjust it several times to get it to work under a load right.

 

[rccktmn2-HT]

I must have missed the spacer, I don't have it so I'll be locating that one somewhere on the toolbox. Thanks for the pic that really showed more detail on what I was missing. When I have the fuel lever pulled back (full fuel) and the lever has the slider on the pump all the way back I'm getting fuel (white smoke) but the engine still does not start. Any thoughts. I mean even without the spacer if I can push the rod back to full fuel the pump the engine should still start shouldn't it.

 

[winston-HT]

<QUOTE author="rccktmn2"><s>

</s>I must have missed the spacer, I don't have it so I'll be locating that one somewhere on the toolbox. Thanks for the pic that really showed more detail on what I was missing. When I have the fuel lever pulled back (full fuel) and the lever has the slider on the pump all the way back I'm getting fuel (white smoke) but the engine still does not start. Any thoughts. I mean even without the spacer if I can push the rod back to full fuel the pump the engine should still start shouldn't it.<e>

/e></QUOTE>

Yes, I agree it should probably crank if system is bled, and pump is pumping. I hate to even mention this but will anyway. I wonder if it is possible the overheating took the starch out of your rings and your compression has dropped? Does the starter spin your engine fast even when the compression release is pushed in? You may have to check compression. Once your satisfied with your pump and bleeding and a no go that would be my next thought.

 

[rccktmn2-HT]

I have definately got compression so I know that is not the problem. You can definately tell the compression strokes when she is turning over so I have to believe the rings and cylinders are good and when I had the head off I looked at the liners and pistons and there were no scorched marks or overheating marks at all so I have to believe the overheating was contained to the head only. I bled the pump and lines all the way to the injectors and I'm definately getting fuel and when I crank it over I'm getting smoke so that tells me that I'm getting fuel into the cylinders. The only thing I can think of is the fuel lines, when I replaced the pump I messaged the lines to fit the new pump, could this have thrown off the timing? If so how can you tell if the pump and injectors are out of time?

 

[winston-HT]

Although the parts drawing does not show shims on your 1500 I assume the injector pump is timed with shims between pump and housing. If you put the pump back on with the same shims that it came off with your timing should be correct. Your fuel lines have nothing to do with the timing.

Did you remove the pistons when you had it apart?

 

[rccktmn2-HT]

Nope didn't remove any pistons, just turned it over a few times with the oil pan off to check for any other damage that might have occured. I installed the new pump with the old shim and everything is working as far as the plungers on the pump riding on the cam lobes and movement, nothing is binding or anything. I know by working on larger diesel engines the fuel lines are in a certain order and layed out a certain way because of timing so I figured that if I moved them or rebent them into a different position it may have affected timing but on the other hand it is a hydraulic action. Thanks for all the help by the way!

 

[winston-HT]

I haven't really helped but trying. Of course if you reversed the lines I guess timing could be affected. In your first post you stated you replaced the injector pump pushrod. Probably a type o, if there were a comma there it would read different. I'm thinking you were just meaning valve pushrod.

Bottom line on the pump timing is if there were no new injector pump parts and it went back together just like it came off the pump should be in time. Of course with the lines on the right cylinders.

I guess we have been over this but if you barely crack your fuel lines at the injectors do you get fuel and no air. High pressure there so be careful.

If the answer to that question is yes and you are satisfied the lines are on correct cylinders and pump is back on just like it came off I am going to suggest again my next move would be to check compression.

 

[rccktmn2-HT]

Okay so today I went out and double/triple checked everything. I made sure the injector lines were on the right cylinders, made sure I had fuel coming out of them when the engine was cranking over, I've also got smoke coming out of the exhaust, so I guess my next question is how do you check compression on a ym1500? The only thing I can think of that is different is the injection pump, my old pump has the 90 degree fittings and the new one has straight fittings on it but I wouldn't think that would matter.

 

[winston-HT]

You will need a compression gage and adapter similiar to this. Be sure and read about the injector removal tool also. <LINK_TEXT text="http://www.hoyetra...Code=HTE&amp;Product_Code=ct-2000</LINK_TEXT> It just sank in on me that you have replaced your injector pump, so yes, it could be out of time. If you don't have a repair manual for your 1500 you are going to need one or someone is going to have to help you that has the correct timing sequence for it. I have one for a 3 cylinder ym220. It is probably different than your 2 cylinder. I apologize for not realizing you had replaced the original pump. Wording in your first post messed up my old mind. Before investing in a compression gage you might well want to go through the timing process. I am sort of doubtful that is the problem but there would be no expense in checking it other than possibly investing in a manual.

Back again. I am going to post timing instructions for a ym220. May be enough similarity for you to figure out how to check your timing. Sorry for all my confusion. As is evident, page 1 is on bottom.

 

[rccktmn2-HT]

Alrighty, I did check out the compression tester and I made my own with some bar stock, I removed the number 1 injector and the closest thing I had to a compression gauge was a differential pressure tester, so I hooked it up and cranked it up to about 30 psi with both valves closed and number 1 on the compression stroke at tdc and there is a lot of air leakage coming from the oil pan area. I had the inspection cover off and the oil fill cover off and I heard the leakage from both areas, I also checked the exhaust and intake and heard no leakage from those areas so I am going to say I have bad rings. I am going to check out the timing just to be sure and invest in a manual. Thanks for the help. You wouldn't happen to know what the compression is supposed to be on this would you? Thanks again.

 

[winston-HT]

Don't know about a 1500 but can tell you the ym220 is to be 568 to 639psi. Lower limit 426psi. Manual says an engine with 426psi or less will be hard to start and is in need of an overhaul. Goes on to say if pressure is much lower than shown, remove gauge and apply oil to the ring area of piston through injection nozzle hole. Do not use too much oil. Do not get oil on the valves.

Test compression again. If pressure is higher, worn or stuck piston rings are indicated. If the pressure is still low, it is possible that valves are worn or sticking.

It is very important that all cylinder pressures be approximately alike. There should be less than 25psi difference between cylinder pressures.

Amen and Amen!

Edit again! If you are getting considerable leakage with 30psi of air pressure that doesn't sound very promising.

And yet again. For what it is worth the ym276 3 cylinder compression is to be 497 to 569psi @ 300rpm. Thinking that is starter speed.

 

[littleguy-HT]

If you have a lathe you can build a tool to insert in place of the injector to check the compression. After putting some oil in the cylinders, try using a little ether while cranking. If it cranks, then yes it's rings.