743B V1702 Kubota compression?

[jim743]

I currently have the engine on the floor, and have done a compression test. I found a spec in the service manual that asks for at least 75% of 427-469 PSI warm. Any idea what is acceptable cold (room temp)? I was getting 265,245,230,230. Can you usually get away with rings and a valve job. Or do they generally go deeper? Pistons? Sleeves? The machine was purchased with a dead hour meter showing 4092 hours, so who knows how long it was in operative. There seems to be a fair amount of blow by.

 

[antfarmer2]

If it spun the tires before you pulled it would leave it alone other than ajusting the valves

 

[jim743]

If it spun the tires before you pulled it would leave it alone other than ajusting the valves

It seemed to have a decent amount of power. It has just been such a P.I.T.A to start in the cold. You can't leave it anywhere without a electrical plug. I have a 1500 watt engine heater, new glow plugs,ow40, and after 3 hours of being plugged in. It still can be bitch to get going. I have to crank it over for 60-90-120 seconds to get enough heat in the cylinder to fire. And still, I often have to resort to the either. I would like to have something dependable for the winter.

 

[antfarmer2]

It seemed to have a decent amount of power. It has just been such a P.I.T.A to start in the cold. You can't leave it anywhere without a electrical plug. I have a 1500 watt engine heater, new glow plugs,ow40, and after 3 hours of being plugged in. It still can be bitch to get going. I have to crank it over for 60-90-120 seconds to get enough heat in the cylinder to fire. And still, I often have to resort to the either. I would like to have something dependable for the winter.

Do not use ether 10 w 40 if you have to but the valves could make a differance but if I was seeing other put a 2203 I think the number was with 10 or so extra horses for unnder 4000

 

[antfarmer2]

Do not use ether 10 w 40 if you have to but the valves could make a differance but if I was seeing other put a 2203 I think the number was with 10 or so extra horses for unnder 4000

Sorry wd 40 lol and have it cranking when spraying

 

[antfarmer2]

Sorry wd 40 lol and have it cranking when spraying

I had a weak wire going to my glow plugs made a big differance

 

[Tazza]

I had a weak wire going to my glow plugs made a big differance

I'm actually amazed you can get that puppy to start on those figures....
The only way to know is to pull the head off and measure the bores. If they are within spec or close to it, a new set of rings may get you more life out of it. I bought some old dismantled engines, one was worn, but the bores were JUST within spec, new rings and it fired up better than any other machine i had.
I actually got a machine that must have run at some point, it's ring end gap was a good 2-3mm! i have no idea how they started it, but it must have worked to wear down that much.
Getting the head checked isn't a bad idea, but if it looks good and the valve seats look clean, you may get away without spending more on it. I would hate for you to spend a fair bit of cash and find out the new rings didn't lift the compression much.
If you are mechanically inclined, pull the head off, see what the wear is like, slap new rings in and see what compression you get. New rings and head gasket will run you a little bit, but it may be worth the gamble.

 

[antfarmer2]

I'm actually amazed you can get that puppy to start on those figures....
The only way to know is to pull the head off and measure the bores. If they are within spec or close to it, a new set of rings may get you more life out of it. I bought some old dismantled engines, one was worn, but the bores were JUST within spec, new rings and it fired up better than any other machine i had.
I actually got a machine that must have run at some point, it's ring end gap was a good 2-3mm! i have no idea how they started it, but it must have worked to wear down that much.
Getting the head checked isn't a bad idea, but if it looks good and the valve seats look clean, you may get away without spending more on it. I would hate for you to spend a fair bit of cash and find out the new rings didn't lift the compression much.
If you are mechanically inclined, pull the head off, see what the wear is like, slap new rings in and see what compression you get. New rings and head gasket will run you a little bit, but it may be worth the gamble.

I would still try ajusting the valves first and see if it helps

 

[orsllc]

I would still try ajusting the valves first and see if it helps

What is the outside temp when you are trying to start it? How long are you engaging the glow plugs for? Even though you put new glow plugs in are you sure they are getting power? Is your engine stop adjusted where it is fully off? Sometimes the cable sticks. Why do you say it has allot of blow by? My 743 takes 60 to 90 second glow plug engagement when it is below 30 degrees F. And it may take 5 tries before she fires off and runs without stalling.

 

[jim743]

What is the outside temp when you are trying to start it? How long are you engaging the glow plugs for? Even though you put new glow plugs in are you sure they are getting power? Is your engine stop adjusted where it is fully off? Sometimes the cable sticks. Why do you say it has allot of blow by? My 743 takes 60 to 90 second glow plug engagement when it is below 30 degrees F. And it may take 5 tries before she fires off and runs without stalling.

-10 to -15 F. Glow plug are on at least 90 seconds. The engine stop is solenoid controlled. I had to put the hose of the valve cover vent tube in a jug as is t was making a mess in the engine compartment. I did do a leak down test today. All the intake valves are leaking. There would not be much point in doing just a valve job, as the blow by will only get worse. I am wrestling with the decision of pulling it apart now.... or wait till fall. I had looked at some parts online from Kumar Bros. Does any one have any knowledge of the quality of their products?

 

[antfarmer2]

-10 to -15 F. Glow plug are on at least 90 seconds. The engine stop is solenoid controlled. I had to put the hose of the valve cover vent tube in a jug as is t was making a mess in the engine compartment. I did do a leak down test today. All the intake valves are leaking. There would not be much point in doing just a valve job, as the blow by will only get worse. I am wrestling with the decision of pulling it apart now.... or wait till fall. I had looked at some parts online from Kumar Bros. Does any one have any knowledge of the quality of their products?

Have you looked at the valve ajustment?

 

[7LBSSMALLIE]

Have you looked at the valve ajustment?

I suppose that what are askining from this unit is the first question, need it every now and again, or tryinining to make a livening with it., if its every now and again, don't know how to say this but that 1702 once you get started will run and run, dam thing will work at 98psi compression (she make smoke a tad) but it is a throwaway, rebuild is probhitively expensive, if its already done as in smoking hard to start etc limp it on, glow ether it who gives a crap if you can start it run it ,blow it up probally five years from now,the other side of the coin is if now starts and runs it does have some retail value. puttining 7 grand into a unit that is worth 2,00 ? no brainer kill it or run it or trade while you can

 

[antfarmer2]

I suppose that what are askining from this unit is the first question, need it every now and again, or tryinining to make a livening with it., if its every now and again, don't know how to say this but that 1702 once you get started will run and run, dam thing will work at 98psi compression (she make smoke a tad) but it is a throwaway, rebuild is probhitively expensive, if its already done as in smoking hard to start etc limp it on, glow ether it who gives a crap if you can start it run it ,blow it up probally five years from now,the other side of the coin is if now starts and runs it does have some retail value. puttining 7 grand into a unit that is worth 2,00 ? no brainer kill it or run it or trade while you can

Hey 7lBS do you think if the exaust valves were loose it could have blow by and low comp

 

[antfarmer2]

Hey 7lBS do you think if the exaust valves were loose it could have blow by and low comp

Sorry all valves were loose

 

[jim743]

Sorry all valves were loose

I had removed the rocker shaft to perform the leak down. I hear what your saying 7lbs. It can be tough to get going at times, but when it running it gets the job done. I was thinking if I could get away with a valve job and a set of rings to breathe a bit more life into it, might be worth a few $$$ investment. I see lots of these engine kits come with pistons and sleeves.......Are these prone to piston and sleeve issues? I am concerned about opening a can of worms!! $300.00 for rings & gaskets. + $200.00 with pistons. + $70.00 with engine bearings. + $190.00 for sleeves. + valve job. The labor I would do myself. But what other surprises are inside? I had checked the oil pressure not long ago, which was surprisingly good. I have been looking for a good used 1702, but have not run across anything yet. I found a new engine for $5000.00, but can't justify that. This unit is not making me a living. I use it for snow clearing on 4 properties and will need it for some landscaping this summer. I could justify $1000-$1500 for a rebuild, but not much more.

 

[antfarmer2]

I had removed the rocker shaft to perform the leak down. I hear what your saying 7lbs. It can be tough to get going at times, but when it running it gets the job done. I was thinking if I could get away with a valve job and a set of rings to breathe a bit more life into it, might be worth a few $$$ investment. I see lots of these engine kits come with pistons and sleeves.......Are these prone to piston and sleeve issues? I am concerned about opening a can of worms!! $300.00 for rings & gaskets. + $200.00 with pistons. + $70.00 with engine bearings. + $190.00 for sleeves. + valve job. The labor I would do myself. But what other surprises are inside? I had checked the oil pressure not long ago, which was surprisingly good. I have been looking for a good used 1702, but have not run across anything yet. I found a new engine for $5000.00, but can't justify that. This unit is not making me a living. I use it for snow clearing on 4 properties and will need it for some landscaping this summer. I could justify $1000-$1500 for a rebuild, but not much more.

I found a bunch of 2203 engines for under 1,500 more horse power and will fit might have to step up the governer and swap out some of your parts

 

[antfarmer2]

I found a bunch of 2203 engines for under 1,500 more horse power and will fit might have to step up the governer and swap out some of your parts

On ebay

 

[antfarmer2]

On ebay

Ebay has the rebuild kit for the 1702 for under 700 but no info on how good it is if mine ever goes out I am going with the 2203

 

[jim743]

Ebay has the rebuild kit for the 1702 for under 700 but no info on how good it is if mine ever goes out I am going with the 2203

My curiosity got the best of me today, and I pulled off the head. Not what I was hoping for!! It looks like it will need to be sleeved. I don't think the .5mm oversize piston will even come close to cleaning up. Plus there are some odd horizontal marks on the cylinder that may be cracks. Now what to do??? Fix it, put it back together or purchase one of these V2203. I had one fellow tell me not to use a reefer motor. But I am sure most of the used ones out there are from that application. I believe he said it had something to do with the governor. I also remember seeing something about the rear engine mount plate doesn't fit the v2203, but the flywheel and starter will. Not sure what that's about.