My ignition timing is on. Good point about the points, I'll just replace em, and re-set them and see what that does before I take the motor out. As far as valve timing goes, it seems fine by just looking at the rockers, but I haven't taken the timing cover off to check. I ran a remote starter switch (one of those hand - held ones) into the cab, and cranked it while moving all controls, and she's cranking as fast as she can. It just seems slow to me. Maybe my starter's fubar. That's entirely possible.
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You might also try running a temporary jumper wire from the positive on the battery to the coil, I seem to remember there is a resistor from the ignition switch going to the coil and by wiring it directly it gives it a much hotter spark if it is hard starting. When it starts just remove the jumper wire. I have a bobcat 732 with the same engine, and when it's hard starting I will use that to get it running every time.
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I have a brand new Pertronix ignitor and coil I can sell you for cheap if you want to get rid of the points and resistor. I bought it because I had to start throwing parts at my 742B that would not start. Ended up being a weak fuel pump so I did not use it.
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I tried the jumper wire trick, and I did confirm firing order. Base ignition timing is about 5 BTDC. I also could not guarantee the aux hydraulics weren't interfering, so I took the quick disconnect off the aux and put a hose on the fitting, the other end in a bucket. The point of that being, any pressure would be relieved. There was none. Still cranking too slowly IMO, and no start. Time to pull that motor!
I got tired of cranking and nothing happening, so I tore into it. The bores look real good. The head does, too. A valve job and new rings (and a hone, of course), and I'm thinking I'll run like new. Good news is, I can get a ring set from Summit Racing for under 100 bucks. I think I'm in pretty good shape! Next week I'll drop the pan and pull the pistons, and measure the bores before I order rings.
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I was thinking of making a vid showing the cranking and post it on here. Maybe my concept of "slow cranking" is normal for this engine. I'll do that tomorrow.
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Have a look at your starter. One of our 732s turned over very slow too, slowly got worse over time… so my dad took the starter apart and it was just full of packed dirt and debris that got in there over the years. Cleaned everything out real good and now it spins over real nice.
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A couple obvious items, but I'd also make sure the battery and wiring is in good shape.
I pulled the engine (now that was a pain). I'm just going to order some rings, and it'll be fine. The engine spins up plenty fast enough when it's out. I'm sure it'll run soon. My concern now, though is the pump. It takes quite a bit of effort to turn it by hand. By that I mean, I can't turn it by hand, I have to put a wrench on it to turn it. I'm wondering if that's what was causing my slow crank. I've pulled a few engines out of a few skids, but I've never tried to turn the pump while the engine was out. How hard should that pump be to turn?
Fabricator
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I'd really doubt that you'd be able to turn the pump by hand under pressure.
There's no pressure.
Fabricator
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Even if you're not driving anything (drive motors, lift cylinders), the pump would be building pressure unless you have the hydraulics open.
I claim no expertise, but guess that your engine would have started and run OK (maybe not great) had it been disconnected from the pump.
My guess is that one should be able to turn the pump by grasping the U-joint yoke and putting forth some effort. I would not expect to need a
big wrench.
My guess is that one should be able to turn the pump by grasping the U-joint yoke and putting forth some effort. I would not expect to need a
big wrench.
Hotrod1830
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If all of the hydro valves are open(i.e. sticks in neutral and pedals in neutral), you are only moving fluid while cranking. There should not be enough resistance to keep an engine from starting. Yes, there will be some resistance, but not to the point you are blaming it on a slow crank concern. You should be able to turn the pump by hand. It wont be easy. Keep in mind you are turning 2 tandem pumps and a hydraulic pump at the same time. The measurement should be in inch/pounds, not lb/ft of torque to rotate.
By now you have the engine out and if in doubt, should have rotated the engine by hand and verified the engine is free to turn. If you did not find a seized or spun bearing, fluid/ rust in the cylinder or something just plain not right, then it probably isnt the root cause to the slow crank.
The pumps can be separated, and rotated separately. You can also remove the hydraulic filter and cut it apart to look for metal debri. keep in mind a small amount of metal is normal in the filter. If you have trouble finding it, it is probably normal. If it is the first thing you see, then probably not.
By now you have the engine out and if in doubt, should have rotated the engine by hand and verified the engine is free to turn. If you did not find a seized or spun bearing, fluid/ rust in the cylinder or something just plain not right, then it probably isnt the root cause to the slow crank.
The pumps can be separated, and rotated separately. You can also remove the hydraulic filter and cut it apart to look for metal debri. keep in mind a small amount of metal is normal in the filter. If you have trouble finding it, it is probably normal. If it is the first thing you see, then probably not.
As it turns out, my cranking was normal. The manual for that engine actually specifies a cranking RPM, and that's where it's at. It just felt slow I guess. The engine is indeed out, and actually finished (I hope) and ready for a test run tomorrow. I'll have it mounted in it's ... mount thing, and sitting on the bench, temporarily connected to battery and fuel, and hopefully I'll hear it run. I'll take a vid and post that too.
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