Low compression on KE70 need parts source

[bolensg154]

I want to rebuild my KE70 2cyl Bolens G154 iseki
Where can I get Piston, rings oversized pistons???
Head gasket.....etc....

Has anyone tried using other available pistons, boring to match.
Hardest part would be finding wrist pins to match.

 

[fxrs55]

how long have you had this tractor? are you sure what is wrong with the engine
that is causing the low compression? I ask because when I got mine it had no
compression in one cylinder and almost none in the other. I was able to fix
mine without new rings or pistons. I did buy a new head gasket and other
Mitsubishi engine parts like valve seals and valve guides from this place.

Small Import Tractor Supply - Home

I have also bought parts from a member here " Lens12 "

https://www.japanesetractorparts.com

 

[bolensg154]

Thank you I will call them.

 

[bolensg154]

My dad purchased this tractor new in 1978
It just slowly lost power while mowing the lawn about 14 years ago. After thinking it was out of fuel I checked the tank, it had fuel to the pump but nothing out of the pump. I put in the barn and it sat for 14 years,
two weeks ago i pulled the injector pump and injectors and had superior diesel go through it and test the injectors,all good except it wont start.
I checked the compression and both cylinders are 150 and 125.

 

[fxrs55]

My dad purchased this tractor new in 1978
It just slowly lost power while mowing the lawn about 14 years ago. After thinking it was out of fuel I checked the tank, it had fuel to the pump but nothing out of the pump. I put in the barn and it sat for 14 years,
two weeks ago i pulled the injector pump and injectors and had superior diesel go through it and test the injectors,all good except it wont start.
I checked the compression and both cylinders are 150 and 125.

read this thread.

http://www.tractorbynet.com/forums/iseki/273164-bolens-g154-iseki-tx1300f.html


when i got my tractor it had sat for well over 15 years.
it had no compression in one cylinder and very little in the other.
read what i found wrong with mine and what i did to fix it.
It now still runs very good and starts easy every time.
My rings were stuck in the pistons, the valves were not
sealing well when fully closed on the valve seat and so on.
check that thread before you start throwing money
at yours.

 

[Ilikeurtractor]

As fxrs55 stated always start with the easy/cheap fixes first. At some point though, you will invariably need to address a low compression problem which may only be remedied by new rings and/or pistons. I just went through a KE70 and trying my hardest to keep costs low and doing the minimal I ultimately ended up boring it out. The piston to cylinder clearance was approaching 0.020" in some places. The new pistons could actually be inserted partially into the cylinder, skirt end first before boring. I tried honing and new rings for the original pistons first which I have successfully done in the past on other engines with little gain. The rings were supposedly changed shortly before I bought it too and upon disassembly I found a broken top ring on the #1 cylinder which appeared to be caused from the rather thick ridge that wasn't removed before installation of the new rings. I thought if I fixed that I would be good. Blowby was horrendous on the engine. You could actually see smoke rising during starting up through the head with the valve cover off. Also found a bent rod on that cylinder which ended up being straightened in a press (not ideal, but works).

I ended up buying parts from NCW tractor because I found their prices to be the most competitive and I never had any issues with their parts working. Be advised though that new pistons from them for the KE70 have recessions in them that look similar to valve reliefs equating to about 4 cc of volume. Running some quick numbers, if the engine was designed at 20:1 compression this 4cc of additional volume will lower the ratio to 17:1. I'm not sure how hard it is to find oversize "flattop" pistons.

 

[lens12]

I can supply Mitsubishi parts, aftermarket parts, or I have good used engines.

 

[Ilikeurtractor]

Thoughts on cylinder honing and re-ringing:

G154 cylinder bore condition and hone - YouTube

Continuation:

G154 hone and new rings - YouTube

 

[HomesteadOC]

Thoughts on cylinder honing and re-ringing:

G154 cylinder bore condition and hone - YouTube

Continuation:

G154 hone and new rings - YouTube

Any updates on how the rings are working with coolant and covers back on? I have a 77 Satoh Beaver S370D KE70 0.7L diesel with possible ring issues. It didnt sit as long (6mo), but my compression is low #1 275psi, #2 300psi. Seller says it just wouldnt start one day. I put some lucas oil and ATF down the glow plugs to try and free up any stuck rings and Im just waiting for that to work in and save me. Most people say I need a re-ring, but if the re-ring is going to give mediocre results, then I might just opt for a complete overhaul. In your videos I cant really tell, but Im assuming you pulled the rods and pistons out from the bottom without removing the engine. How much easier is that than pulling the engine? Seems like a knuckle busting party with oil in the teeth laying under there. Did you try a can of restore before the tear down? Im thinking thats my last resort before a hone and re-ring.

 

[lens12]

Rods and pistons come out the top without removing the engine. Once head is removed cylinders can be measured to see if just rings will work or if it needs to be bored. I have a couple used KE70 motors that are in good condition.

 

[HomesteadOC]

Rods and pistons come out the top without removing the engine. Once head is removed cylinders can be measured to see if just rings will work or if it needs to be bored. I have a couple used KE70 motors that are in good condition.

Im assuming that you need to pull the oil pan and disconnect the rods from the crankshaft. How big of a deal is that? Im not in front of my Beaver now, but from what I remember when I was greasing things was that there could be something in the way?

My engine cranks great and it sounds like it really wants to get going, the glow plugs were bad due to an wrong ignition switch. Plugs were wired to the acc on and wouldnt get voltage when key was turned left. Either the switch is broke or its a Jerry rigged switch not meant for a diesel. Either way I ordered a new correct switch and new plugs (NGK 6825).

 

[Ilikeurtractor]

Any updates on how the rings are working with coolant and covers back on?

It's starting acceptably (not like I would consider new but I've never seen actual new so I don't know) and runs well. I have KE tractors that start better though. It smokes the least of all my tractors including the one I had bored for new pistons. I'm not sure why but that's what it is. These engines tend to smoke more white in color than blue in my opinion. Blow-by is still pretty high. I doubt any "mechanic-in-a-can" options will work although in the case of stuck rings it could be theoretically possible. I did not try any. Without a mechanical means to distribute the magic potion in the ring grooves it would likely take a long time to free, if ever. Assuming that is even the problem which it may not be. As I stated in my video the rear cylinder rings were completely free and that cylinder had nearly no significant compression. Ideally you should bore and install new pistons, keep the oil changed frequently and you should get well over 1000 hours easy. I would hope 2-3000 or more. I'll hopefully get some idea of how many hours I can get on what I did but collectively I only use my tractors around 100 hours year I would guess and this one will not normally be a "go-to" tractor. As Lens said you can pull the pistons from the top after removing the head. It saves a LOT of time and money over pulling the block for boring as you can imagine. Your mileage will be reflective of the repair of course.

 

[lens12]

Glow plugs working will make a world of difference in starting. If the motor isn't hot they should always be glow plugged.

 

[HomesteadOC]

It's starting acceptably (not like I would consider new but I've never seen actual new so I don't know) and runs well. I have KE tractors that start better though. It smokes the least of all my tractors including the one I had bored for new pistons. I'm not sure why but that's what it is. These engines tend to smoke more white in color than blue in my opinion. Blow-by is still pretty high. I doubt any "mechanic-in-a-can" options will work although in the case of stuck rings it could be theoretically possible. I did not try any. Without a mechanical means to distribute the magic potion in the ring grooves it would likely take a long time to free, if ever. Assuming that is even the problem which it may not be. As I stated in my video the rear cylinder rings were completely free and that cylinder had nearly no significant compression. Ideally you should bore and install new pistons, keep the oil changed frequently and you should get well over 1000 hours easy. I would hope 2-3000 or more. I'll hopefully get some idea of how many hours I can get on what I did but collectively I only use my tractors around 100 hours year I would guess and this one will not normally be a "go-to" tractor. As Lens said you can pull the pistons from the top after removing the head. It saves a LOT of time and money over pulling the block for boring as you can imagine. Your mileage will be reflective of the repair of course.

This will be my go to tractor, and probably my only tractor soon enough. It has a blackhawk front loader and Ill probably be selling the craftsman gt5000 to help cover the cost of this one. I really have no idea on how many hours per year I would put on this, but 100 seems low to me. Maybe 500 tops seems about right. I wish these things came with an hour meter, I guess that could be installed. Is that connected in line with the ignition to run or is it more complicated than that? Once the glow plugs arrive and my correct ignition switch Ill try to start it up and see where were at with compression and if it fires.
Is there any danger to running it on lower than great compression if it does fire? For instance, does it wear the cylinder walls faster and could potentiall ruin my block? Or re-ringing is just the next step when it stops starting, and after that its a full bore job with oversized pistons?

Thanks

 

[lens12]

500 is a lot of hours. i farm. i used to chop hay & haul a lot of manure & put 500 hours a year on. But the that is running dawn to dusk. 500 hours is 12 40 hour weeks.
"Is there any danger to running it on lower than great compression if it does fire?" As long as it has power, it shouldn't hurt.
" For instance, does it wear the cylinder walls faster and could potentiall ruin my block?" No
Or re-ringing is just the next step when it stops starting, and after that its a full bore job with oversized pistons? Yes.

 

[Ilikeurtractor]

Options for an hour meter could include:

1.) Tiny Tach diesel - expensive, may not be reliable in cold weather
2.) Magetic pick-up on front pulley - these aren't cheap either as a turn-key package but you might be able to build your own
3.) Hour meter that runs off ignition switch - will count hours if you don't shut the key off when engine is off
4.) Meter that runs off the alternator - I'm not sure about something in a turn-key package but I've heard about them. I would investigate an hour meter that runs off 6VDC and take the signal off the 'N' line from the alternator to ground or to the '+' pole, either should work as long as you maintain polarity. I haven't done this myself but it should work - might need to add some capacitance to the circuit to buffer/smooth the signal. The 'N' line is only partially rectified (pulse DC) so it may not count hours correctly. Engine speed could be had also using the 'N' line and a frequency meter. It would need to be converted to engine speed by factoring in the 3 electrical fields and relative sizes of the alternator and crankshaft pulleys. Something like alternator pulley diameter divided by crankshaft pulley diameter divided by 3 (alternator fields) times frequency obtained off 'N' line times 60 (Hz to RPM) should equal crankshaft speed. That may be wrong but would get you started in the right direction. Obviously some work with programming and circuits would be required.

Lower compression just means a less efficient engine (lower power output) with the side effect of quicker oil contamination, more black smoke due to lower amount of air charge (oxygen) and, of course, harder starting until it eventually will not start at all. Think about it like this: if you go to compress the air brought into the cylinder and some of it escapes past the rings there is less air available to combine with the fuel when it is injected. Therefore less fuel can actually burn completely resulting in less power and more black smoke which also blows by the piston creating carbon buildup in the rings and oil. All of this contributes to accelerating wear of the engine (snowball effect). This is also why spark ignition engines will not run with low compression even though they can fire independently of the heat of compression as a diesel needs. If the air/fuel charge blows past the piston during the compression stroke there is nothing left to actually burn above the piston, or at least enough to force the piston to move significantly. What I haven't quite figured out yet is why the charge does not fire in the crankcase of a 2-stroke engine when this happens. That would be a bad day but I've never heard it happen. The ignited charge must never make it past the piston and to the crankcase because of the exhaust ports somewhat acting as a barrier but I'm not for sure about that.

 

[HomesteadOC]

500 is a lot of hours. i farm. i used to chop hay & haul a lot of manure & put 500 hours a year on. But the that is running dawn to dusk. 500 hours is 12 40 hour weeks.
"Is there any danger to running it on lower than great compression if it does fire?" As long as it has power, it shouldn't hurt.
" For instance, does it wear the cylinder walls faster and could potentiall ruin my block?" No
Or re-ringing is just the next step when it stops starting, and after that its a full bore job with oversized pistons? Yes.

Maybe its more than Im thinking, but now that you explain the time like that Id say Id use it 3-5 hours per week. Thanks for the answers, really appreciate it. I just got my plugs in, but still waiting on the ignition switch. I could probably just put them in the way they are now and see what happens, but I want to give the cylinders at least a week to soak.

 

[HomesteadOC]

Ordered a $10 diesel hour meter, and compression is up substantially (455psi and 550psi on 1 and 2), not sure how this could happen, but I should probably retest after work tomorrow to confirm. Still wont start, but I have new glow plugs and compression is up, fuel is bled to injectors and shoots out the plug hole during compression testing on both cylinders. Where should the throttle lever be when starting? All the way forward, backward, middle?

 

[Ilikeurtractor]

How much smoke is coming out of the exhaust when you're cranking? If very little or none, you're not getting any fuel. If it's white, there's not enough heat to burn. If it's black that needs further investigation but should run. Fuel lever should be to the full fuel position (pump lever towards the rear against the pump stop - on a S370D the lever is towards the rear also.)

 

[HomesteadOC]

This is my first time working on diesels so Im really not sure what a lot or a little could be. The smoke was black with a blue tinge to it, every crank was enough smoke to make you choke your butt off if you were sucking on the exhaust pipe. Definitely noticeable, but not a billowing cloud, id say medium to light amount. I tried starting with lever all the way forward and all the way back as I was cranking, but Ill keep it towards the rear from now on. I was reading the operating manual and it says to start in the middle, but thats probably for a tractor fresh out the crate. Thanks for the help, Ill double check my compression readings and try to start again when I get home.