Advice needed for first Kohler engine rebuild

[wallfish 16,994]

10 hours ago, tntatro said:

Does seeing black smoke after a rebuild mean something isn't right? I did forget to flip the choke lever back at first, I thought that might have caused it. 

Black smoke is the extra fuel from it being over choked.

[953 nut 55,198]

5 hours ago, tntatro said:

I found that searching the part number was better than searching the name of the part.

                Lots of NOS Kohler parts on  are listed by part number only because the seller doesn't know what they are selling and are too lazy to look it up.           

[tntatro 171]

The machine shop told me that the rod would be fine as long as I put it back the way it should be and the oil hole is facing the right way.

 

As far as the lifters he said that they aren't that hard, they are a grade 8 bolt and should be able to be filed. He said almost all that they get in need to be resurfaced.

 

I guess I'll put the motor on the tractor next chance I get.

[ebinmaine 67,455]

Super cool. Keep us posted.

[tntatro 171]

If I break a rod halfway through the season I'll let you know.

 

I was going to replace the crankshaft and lifters, now I guess I need another k241 with a bad crank and rod.

[953 nut 55,198]

On 4/7/2019 at 8:07 AM, tntatro said:

I found that searching the part number was better than searching the name of the part.

                Lots of NOS Kohler parts on  are listed by part number only because the seller doesn't know what they are selling and are too lazy to look it up.           

1 hour ago, tntatro said:

machine shop told me that the rod would be fine

If I were you I would use some Plastigage to check the fit before you bolt it up.

 

[bc.gold 3,403]

10 hours ago, tntatro said:

The machine shop told me that the rod would be fine as long as I put it back the way it should be and the oil hole is facing the right way.

 

As far as the lifters he said that they aren't that hard, they are a grade 8 bolt and should be able to be filed. He said almost all that they get in need to be resurfaced.

 

I guess I'll put the motor on the tractor next chance I get.

 

What did the shop have to say about over torquing the connecting rod stud threaded into the aluminum rod. The statement below refers to a connecting rod bolt as that shown below and not a stud threaded into aluminum.

 

The last image, those thread into an iron connecting rod.

Understanding Stretch

A bolt functions similar to a spring, in that it needs to be stretched beyond it’s static length in order to apply a clamping force.

 

Edited April 9, 2019 by bcgold

[tntatro 171]

This connecting rod doesn't have the studs with nuts that tighten down, it has bolts or I guess cap screws. I explained to him what I did and he just said, "Yeah, they don't get them perfect but they get them really close. Did you put the oil hole facing the camshaft?"

 

 He seemed much more concerned about the placement of the oil hole. I asked if he was sure it would be okay because I have a bit of money in it and he very confidently insisted that it would be fine. 

 

At this point I'm going to leave it and take this as a learning experience. If it breaks then I'll know to replace the rod if I happen to make the same mistake again.

[ebinmaine 67,455]

1 minute ago, tntatro said:

learning experience

That's the right attitude and the best type of education

 

 

 

[bc.gold 3,403]

3 hours ago, ebinmaine said:

That's the right attitude and the best type of education

 

 

 

My father once told me that it would cost to get an education but cost nothing to pack it around once you have it.

[tntatro 171]

Today I mounted the engine on the frame but now the hood doesn't fit. It hits the air filter housing. I am replacing an 8hp engine from a 1973 8hp 4 speed. I still haven't got the wires hooked up.

[ebinmaine 67,455]

Not sure how the engine would react but you may be able to switch to a 10/12 HP air filter housing. They're thinner.

 

 

[tntatro 171]

I'm switching from an 8hp to 10hp engine so I already have the 10 hp air filter housing. It looks like I will either have to cut a hole in the front, get a different hood, or rebuild the 8hp engine and put it back on.

[ebinmaine 67,455]

Another option would be to make up a pipe elbow air filter Inlet such as I did on Trina's 657 when we put the 8 horse Briggs on it.

[tntatro 171]

13 hours ago, ebinmaine said:

Another option would be to make up a pipe elbow air filter Inlet such as I did on Trina's 657 when we put the 8 horse Briggs on it.

How do I do that?

[tntatro 171]

I got the engine wired and it starts and runs but my tachometer isn't working right and the numbers are all over the place so I have to get a new one.

 

I don't really understand how to set the spring for the governor and the high speed stop properly. Is it just about getting it so it doesn't rev too high?

[pfrederi 17,734]

The manual shows what holes to put the spring in.  The high speed stop you just move a bit and check the speed with your tach.  it doesn't take much movement for significant RPM change

[ebinmaine 67,455]

1 hour ago, tntatro said:

How do I do that?

We can get a pic or 2 tomorrow

[pfrederi 17,734]

[tntatro 171]

I got a new tachometer and adjusted the high speed to about 3,600 rpm but then my new tachometer started jumping all over the place. It is an hour/tach and I think the spark/pulse input changed because it seemed to work great until I drove the tractor. I'll try again tomorrow. The settings are 1p1r, 1p2r or 2p1r. I don't know which it is supposed to be but i guess I can try them all. It came set at 1p1r according to the manual and was set there when I checked after it started having sporadic readings.

[tntatro 171]

I mowed with it for a couple hours today. I'm pretty sure it is set to 3,600 rpm because my tachometer works sometimes. It seems to have good power but I think I overheated it a little. When it got low on gas it kept bogging a little and smoke would come out of the valve area. I didn't realize it was low until it ran out. The 8hp motor that was on it could mow the whole lawn on one tank of gas and still have gas in the tank, this one seems to be a gas hog compared to the other. It ran fine again after filling it up. The deck is a little big for it also at 48". I have a 42" that needs to be repaired that will eventually go on it.

 

I don't think the hood will fit well enough even with a modified air filter because the muffler would also need some elbows. Between the hood not fitting and the gas consumption I may put the 8hp back on after I rebuild it and put this one on a different tractor.

 

Does the bogging down and overheating when low on gas indicate a different problem other than needing gas? I've run out of gas in mowers before without this happening.

[bc.gold 3,403]

Put some hours on the clock and your fuel consumption will improve, overheating could be caused by a number of things.

 

 

[tntatro 171]

5 minutes ago, bcgold said:

Put some hours on the clock and your fuel consumption will improve, overheating could be caused by a number of things.

 

 

That's good to know about the gas consumption improving. As far as the overheating it seemed like the low gas caused it to lose power and overwork the engine with the deck engaged. After filling the tank it was back to normal. Maybe it could use some fine tuning on the carburetor. 

[bc.gold 3,403]

1 hour ago, tntatro said:

That's good to know about the gas consumption improving. As far as the overheating it seemed like the low gas caused it to lose power and overwork the engine with the deck engaged. After filling the tank it was back to normal. Maybe it could use some fine tuning on the carburetor. 

After the required break in hours have been reached that first oil and filter change is an important one as it removes any swarf ( fine grit ) from honing, piston rings seating in etc.

 

Lean fuel mixture could be a cause for over heating, or timing to far advanced.

Edited April 17, 2019 by bcgold

[tntatro 171]

I'll mow one more time and then change the oil and re torque all the bolts first. There is a little oil leaking from the fuel pump and breather. The fuel pump has phillip head screws and was a little hard to torque. I don't know how tight the breather assembly needs to be but I'll tighten it a little more and see if it stops leaking.

 

I'm also going to mess with the governor spring location and carburetor. I just read through the manual again so I might be able to adjust things a little better next time.