SailNet Community banner
1 - 17 of 17 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter · #1 ·
A few month back bringing Kare Knot down the intercoastal a slow oil leak caused my oil level to run low. Since it was coming from the back of the engine I decided to pull the engine and change all the seals and gaskets. I boomed the diesel into my tender and lugged it tom my garage. In the process of cleaning I broke a ring and decided to change the rings. Ordered one of those $15 dollar honing tools and commenced to destroy the inside of my cylinder walls (don't try to do this yourself!) Thinking that I had done a good enough job I reinstalled the engine (not fun!). Any way after a few days of trying to get the fuel lines to bleed the 2 banger came to life. Like 3500 rpm of life!!! Anyway if you've never had this happen it will scare the crap outta you! Finally covered the intake and the engine reluctantly sputtered to a stop. Decided to drink a beer and give it a once over. Nerves calmed I tried again with the same results. My first intuition was it was the injector pump which I took apart as part of rebuild (allso not a good idea!). So took it to an injection specailist and forked over $200 for my precision tuned pump. Installed the pump and holy crap it ran away again. Now my worst fear set in... my crappy honing job! I winched out the engine again and brought it for a professional honing. The checked the wall diameter, ring gaps mating surfaces and put a nice cross-hatch on the walls. Meanwhile smeone stole my $2000 dingy and engine! Anyway winched the motor in for the second time. Checked ever detail while reassembling. Started her up and it fricken ran away again. I'm out of ideas... Pulled the injectors and will have them tested this week. If this doesn't fix it I'm all out of ideas. Anyone with any other ideas I sure would appreciate it! Here's a list of what I chaged so far:

New rings
Front & rear main bearings
Rod bearings
Front & rear seals
Injector mating seals
New head gasket (well all new gaskets)
Replaced the soft fuel lines.
Rebuilt injector pump
2 quarts of oil
Valve stem seats

Professionally rehoned and certified valve steams, seat ok, ring gap and mating warp ok

Now just some notes, blowing blue smoke. Disconnected fuel supply and the engine stopped. The spring between the injector pump and the throttel inhibitor seems looser that it should. Moving the throttle while running does not impact speed.

Any ideas would be greatly appreciated!!!!!!!!!! :confused:

Thanks EZ
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #4 ·
Thanks for your replies. First the throttle cable is not connected at this time but I've turned it while the engine is running and it will rev faster but not slower (strange). I have had the breather cover completely off while the engine was running an it made the engine run faster because I could no longer control the air supply by way of the air intake. Not sure what you are talking about when you say lift pump diaphram? The oil pump on the 2qm is external on the flywheel side and driven by the cam shaft. Yes the engine ran very well before.
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #7 ·
Thanks Paul. Just got back from the injector shop. Had my injectors flow tested and they are fine. The injector pump was professionally rebuilt also. The lift pump on the 2QM is external. Now that kinda points me to two possible culpits... Either there is blow by on the pistons or something assembled wrong on the throttle internal linkage. Like I said the spring that goes from the throttle inhitor to the injector pump arm seems looser than is should. Thought I remember it being pretty tight to get off... God I miss my memory!
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #9 ·
After thinking, the injector pump is external but has a lifter arm into the crank case and actuated by the cam. However, having just rebuilt the engine and new oil, I don't think that on first start there would be dilution yet... The runaway was immediate. Good point on hard starting - in this case it starts easy which points us away from low compression. Could it be that the rings need time to seat? If I control the throttle by partially blocking the air intake and let it run for a while would that damage anything....would they eventually seat? there seems to be allot of vacume in the head (that may be normal) but after I shutoff the engine it takes a heavy 3-4 second breath thru the intake. But I thought if something were creating too much vacume that it could suck oil up or the reverse if there was too much crank case pressure...
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #17 ·
I have no idea if the shims were put back in the same order. If they are off would that cause excessive fuel to the injectors? On the second disassembly there was oily residue on both pistons and the rear #1 compression ring was stuck (these are new rings). The exhaust ports showed heavy carbon build up for having only ran for a few minutes. The new oil was very dark as well and smelled like self lighting charcoal. I freed the ring and when reassembled the second time I cleaned good and lubricated both the cylinder walls and the rings were free moving and well lubricated (and as I mentioned before the cylinders were professionally honed and tolerances were within spec). Kinda wondering if the ring might have stuck again?? I've been racking my brain trying to think of where oil might be entering the intake. If the ring is stuck again what would cause that? Would it be caused from oil entering the intake? Where the heck could the oil be coming from? The valve seals are new too.
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #20 ·
Thanks Paul for your help. The 2QM15 is a pretty simple engine..no glow plugs or turbos or anything. Just fuel, air and combustion (which makes this that more frustrating!). I did take the injector pump and have it rebuilt. Also I did do a garage analysis of the oil. Poured it into a glass jar and let it sit for a few days. There was no visible separation but there was muddy (cabon I assume) at the bottom when I dumped it out. Checking the crank case ventilation hose & housing is on my list of things to check. I'll try running disconnected. Just bought an oil pressure gauge so I'll get some reading on that too. Will also make some temporary injector shims to see if adding additional space will have any impact. I will also pull the head and drop the intake valves to see if I can see any oil residue. Theoretically, it should be dry right? Also ordered a new head gasket. The thought of pulling the engine the third time makes me want to learn to actually "sail" my boat! LOL
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #22 ·
You guys are great troubleshooters! However a truly seasoned mechanic would ask the the most relevant questions first. Which should be..........wait for it........ "are you Polish by chance?" which I would respond "why yes I am! How did you know?" Because you have a 2 cylinder engine and you have a 50/50 chance of getting TDC right. Which would be the flywheel side and not the front you idiot!

Yeh I haven't verified it yet but I aligned timing marks on the crank gear with the cam gear based on forward cylinder being #1. It's the rear (flywheel cylinder)! Feeling really stupid at this point but to my defense the Yanmar manual only mentions the TDC orientation once in the entire manual and it's buried inside a paragraph in the middle of the book! I have to say that I have a new new found respect for Yanmar's if they would even start in this scenario! Let you know how it turns out this weekend. Thank god Paul is in California he can't come down to Miami to kick my Ars for waisting 2 two hours of his life!!!
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #28 ·
Hey Paul. I keep my boat on a city moring. Went out there on Saturday but they shut down the shuttle boat that takes residents to their boat. 15MPH winds and 1 foot swells and the guy has the nads to call himself a captian! Yeh I chomping at the bit to get out there. Promise to post a followup. EZ
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #31 ·
Will, Thanks for the tip. Yes I removed everything from the engine during the rebuild. When I inserted the pump I did make sure the rack ball was inserted in the throttle control assembly. It's hard to say at this point if there are any idle issues or not because I haven't been able to get out there to readjust the timing. However, I lost the position on the stop cable and I'm not sure how to get that in the right position to stop the engine. Also the throttle assembly (spring) seems looser than when I took it off. Not sure if something is screwed up there... Once I get the to the boat I'll have a better idea if I am going to need further help getting the throttle assembly and stop cable adjusted correctly. So I have two shims and will torque to spec but how would I know if the fuel delivery is correct? Thanks for your advice.
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #33 ·
Finally got out to the boat today. Took off the gear cover and tried to set cylinder one (Fly wheel side) to TDC. The timing mark lands 180 degrees away from the cam gear. So there is no way that the timing marks on the cam gear could ever align with the drive shaft in this configuration. So i realigned the timing marks "o"s to "o"'s on both the cam and crank shaft. This puts the front gear side to TDC. Put everything back together again. Started the engine and was running at a high RPM. Resolved to loosen the bolts on the fuel pump. I was able to get the RPM to a normal range. However, the RPM was surging up and down and the throttle response seemed sluggish. Might be because fuel pump wasn't sealed and was either loosing vacuum or vibrating too much. It' still seems to have blow by and smoking allot. There was an oil film in the water. So I think I have two problems; first I need to shim the pump and second I need to pull the pistons to see if I have a ring stuck or something. Once again any of your thoughts are appreciated!
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #37 ·
I was referring to the injector pump (sorry). It has shims that control the height that the injector pistons ride above the cam lobes. Too low and it pumps too much fuel. In my case loosening a little seems to bring the idle down to a normal level. I will get you guys a video
 
1 - 17 of 17 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top