77 Satoh Beaver S370D wont start, low compression

[HomesteadOC]

There probably has been wrenching done before I got it, but not by the seller. He said he had it 2 years and it just ran for him. The serial number suggests 77-78 so Im sure somebody did something in that time, but I have no record of what or when.

I did pressure wash it, until my cheap harbor freight pressure washer broke. I got the undercarraige pretty good, but not the engine. I used straight water the first round and was going to come back with simple green, but it broke. Id like to go through the injectors and make sure theyre 100% before it all goes back together. Is it feasable to rebuild these myself? Or is it something that sent in for rebuild? Is there a solution I can soak it in to dissolve any solids in there?

 

[Ilikeurtractor]

I didnt check timing, not sure how to do that, but maybe its in the manual? [snip] Someone mentioned turning the front PTO to get to TDC, does that require removing the hood and radiator?

Don't worry about timing. There's not a lot you can do to put these engines into specification (25 degrees BTDC). Unless you notice a gasket that is 1/4" tall or more under the pump then you're probably fine. If you're curious I posted about this problem (I believe this actually fixed other, possibly more sinister problems with these engines) here:

http://www.tractorbynet.com/forums/...post4884864.html?highlight=timing#post4884864

In summary, you can't really get the timing more advanced than about 5 degrees BTDC even if you remove all the shims under the pump. I don't know if all KE70s are this way or not. I have one that has an early serial # (below 19,000 if I remember correctly) that I believe is actually running the correct timing but I haven't performed the high frame-rate camera test to prove it out. It is significantly louder (knocking) at idle than all my other engines that are over 40,000 in their serial #s and it seems to run stronger at high rpm and weaker at low rpm vs. the others which would support the original timing spec. Later timing tends to result in better starting and lower noise, but in more smoke typically. My gut feeling is this was a design change made to the cam grind to force a reduction in the noise on the engines (because my older one is way louder) and NOx which may have been an EPA thing even back in the late 70s and early 80s. It also potentially reduces the likelihood of experiencing bent rods and cylinder wear in my opinion.

The front PTO, if you have one, should be accessible from under the radiator. You can also just grab the fan and rotate the engine by rotating the fan if the compression is weak and your belt is tight.

 

[HomesteadOC]

I dont see the serial number on the engine, possibly too much grease and grime. Frame serial number is ST1300D-700383.
Should be easy to turn the engine by the fan since the heads are off and theres no compression. Id like to orientate the pistons at tdc before I put the head back on so I can do the valve adjustment correctly. Which piston should be at TDC, #1?
Heres a picture of my oil pan/drive shaft predicament looks like theres an outer shield to the drive shaft, maybe I just need to pull that to get to the rods?

 

[Ilikeurtractor]

In order to drop the oil pan you normally need to drop at least the front half of the drive shaft. You might be able to pull the pan out with just taking off the drive shaft guard but you'll want the drive shaft out of the way anyway when you start working on the connecting rod caps. Each piston ideally would be around TDC when you set the valves for their corresponding cylinder but that can be inconvenient to get to without being able to see the crankshaft pulley timing marks. That's why I generally just spin the engine and watch the valves. After the intake valve closes for the particular cylinder being adjusted, just turn the crankshaft somewhere between 90 and 180 degrees clockwise (looking towards the rear of the tractor facing the crankshaft pulley) and that will be close enough. These engines aren't really that sensitive to valve adjustment or timing. The biggest concern is making sure the valves are able to close fully to prevent compression losses through them so you want to ensure you're at least have some gap. More isn't as bad as less but a ton of gap won't allow it to breath either.

 

[HomesteadOC]

Could loose valves cause the compression to drop? I would guess that the piston would push them closed during the compression stroke and not make too much of a difference. Im 100-150psi off of ideal for cylinders 2 and 1 respectively.
Ill have to read over the manual for a while, I skimmed through and didnt really see anything about driveshaft removal. Im worried if I split that case I wont get it back in there the way its supposed to go.

 

[HomesteadOC]

Bill Rodgers of Valley Power is the man...no pumpkin splitting required. Remove driveshaft covers, unbolt 4 bolts on the yoke and slide it out the back. Ill be getting back into it after work today and take some pictures and probably a video. After figuring out the youtubes, its actually easier to post videos than pictures using a phone. And if a picture is worth 1000 words, it seems a video should be worth 1000 pictures, right?

 

[HomesteadOC]

Ordered a few supplies on amazon, got coarse and fine lapping compound, lapping tool, prussian blue fitting dye, ring expander, ring compressor, engine assembly oil and brass T for fuel injectors to tank. Was debating over the super fancy assembly oil or buying an oil can and using oil the engine will use, but the assembly oil came in a bottle where I didnt need a can and was cheaper than the can. Still not sure on which gaskets Ill need, but Im pretty sure I can reuse the intake and exhaust, the coolant inlet was an RTV gasket maker job. Im also missing a few bolts here and there, so Ill try and get those replaced. Im missing the bottom 2 studs on my exhaust ports, might be tough to find those, maybe a bolt would be easier? Also noticed a missing bolt on the right side loader support, thats probably important. Still need to order ring set, I need to pull pistons before Ill know which set to get. And the power washing will have to wait til after final asssmbly, all parts will be cleaned in the partswasher before installation though.

 

[Kernopelli]

.....didnt really see anything about driveshaft removal. Im worried if I split that case I wont get it back in there the way its supposed to go.

Your driveshaft case/shield looks similar to the one on my tractor. Simple 2 piece design, it's dry ( no oil,grease, fluid). Remove the perimeter bolts and there are probably 2-4 bolts that hold the shield to the differential and trans cases. Pop the shield's 2 pieces apart and you can get to the front drive shaft and yoke.

I have had great experiences with NCW Tractor Parts, LLC. Over the last 3 years, I've bought all parts for a full rebuild in a K3F engine, some small incidentals and a new larger hydraulic pump from them and couldn't beat their prices. Very easy to work with and seems to know Mitsubishi inside and out.

 

[HomesteadOC]

Todays progress...got the pistons out and checked them out mine have 5 oil holes on each side of the piston (10 total) in case anyone is interested. Top ring looks like its square, a lot of them had to be broken to remove them. I noticed that there are 2 sides to the connecting rods, one has a little nub at the bottom of the end cap and Im not really sure which was theyre supposed to go. I laid them out on the paper towel with the direction they came out of the engine, but I didnt pay attention when I removed the caps and set them aside. Heres a little compilation video.

 

[Ilikeurtractor]

Looks just like mine did except my front cylinder had the stuck rings and the rear rings were free but had the lower compression similar to yours. A hone and new rings should get you back in business. Usually I would have the head gone through with new valves, valve grind, and seals but this last one I didn't. I would still recommend installing new seals but I think if you just do a quick lap of your existing valves that should be fine. On mine the rods had numbers punch-marked into them. Keep the numbers together on the rod and cap. I can't remember if the numbers went to the right or left of the engine, but seems like it was the right. It does matter according to the manual and it says in there somewhere.