In a previous post entitled "Runaway Diesel" back in February, the post managed to drift from, well as the title says, runaway diesels all the way to hand starting a diesel engine.
One facet of the hand starting segment which caught my attention was the difficulty if not impossibility of hand starting a Yanmar engine at a time when the electric start had failed. I promised to look into this once the weather here warmed up :
The first problem encountered was (as previously mentioned in "Runaway Diesel") is that a V-belt sits directly over a cover cap for the starting rod connection :
Here is the cap shown in the Yanmar parts manual :
After removing the offending V-belt, we have a much better shot at getting to the two retaining screws holding the cap in place :
With my trusty assistant wrenching on the hex portion of the #4 Philips screwdriver with a box end wrench and your truly heaving into the screw and twisting with both hands, this machine screw didn't stand a chance. Well, not exactly.
As I'm slowly approaching max. force on the screwdriver, I can feel the screw move slightly but it's just not getting any looser. Maybe a shot of WD-40, a couple of taps, a little heat, and let it sit for an hour while I look at other small things on the engine which I need to do. This time I try it by myself and the screw isn't going anywhere short of snapping off the head. About this time I can hear Kenny Rogers way in the background whispering his wise, words of wisdom : "Ya gotta know when to hold 'em, know when to fold 'em."
At that point I decided if that if I broke the screw thread in the casting, I'm in for a world of hurt. I didn't even want to get in there because the V-belt is most likely going to prevent me from trying to hand start the engine if ever required. The one screw head I worked on was getting a little shop worn around the edges at that point :
.................................... in spite of forcing that driver in as hard as we could.
It was "Time to fold 'em" and forget the whole mad adventure. I replaced the belt, tightened it to 50 lbs :
................................. and that was all she wrote.
I can't help but suspect that Yanmar may have used permanent red Loctite Threadlocker on those small machine screws to signal the end of trying to handstart your Yanmar diesel. And that, I suspect would be why the cylinder unloaders were discontinued on the later YM models of the engine after the GM model was discontinued in 2005. I'm still sitting here wondering if the 2GM20F (including the 1 and 3 cyl. model) was ever intended to be hand started from its inception in 1983.
Any further thoughts out there on hand starting Yanmar GM's and prior models would be welcomed with open arms. What I've seen so far just doesn't quite add up.
One facet of the hand starting segment which caught my attention was the difficulty if not impossibility of hand starting a Yanmar engine at a time when the electric start had failed. I promised to look into this once the weather here warmed up :
Last Wednesday we managed to get up to 16° C (61° F) for one day only in the middle of a cold, wet spell here. Shorts and T-shirt weather right on the water. So it's off to the boat to see if we can hand start the Yanmar 2GM20F.
The first problem encountered was (as previously mentioned in "Runaway Diesel") is that a V-belt sits directly over a cover cap for the starting rod connection :
Here is the cap shown in the Yanmar parts manual :
After removing the offending V-belt, we have a much better shot at getting to the two retaining screws holding the cap in place :
With my trusty assistant wrenching on the hex portion of the #4 Philips screwdriver with a box end wrench and your truly heaving into the screw and twisting with both hands, this machine screw didn't stand a chance. Well, not exactly.
As I'm slowly approaching max. force on the screwdriver, I can feel the screw move slightly but it's just not getting any looser. Maybe a shot of WD-40, a couple of taps, a little heat, and let it sit for an hour while I look at other small things on the engine which I need to do. This time I try it by myself and the screw isn't going anywhere short of snapping off the head. About this time I can hear Kenny Rogers way in the background whispering his wise, words of wisdom : "Ya gotta know when to hold 'em, know when to fold 'em."
At that point I decided if that if I broke the screw thread in the casting, I'm in for a world of hurt. I didn't even want to get in there because the V-belt is most likely going to prevent me from trying to hand start the engine if ever required. The one screw head I worked on was getting a little shop worn around the edges at that point :
.................................... in spite of forcing that driver in as hard as we could.
It was "Time to fold 'em" and forget the whole mad adventure. I replaced the belt, tightened it to 50 lbs :
................................. and that was all she wrote.
I can't help but suspect that Yanmar may have used permanent red Loctite Threadlocker on those small machine screws to signal the end of trying to handstart your Yanmar diesel. And that, I suspect would be why the cylinder unloaders were discontinued on the later YM models of the engine after the GM model was discontinued in 2005. I'm still sitting here wondering if the 2GM20F (including the 1 and 3 cyl. model) was ever intended to be hand started from its inception in 1983.
Any further thoughts out there on hand starting Yanmar GM's and prior models would be welcomed with open arms. What I've seen so far just doesn't quite add up.
