Dave's 1650 Project

[CC1650Dave]

Yeah, I guess a trip to the machine shop is in order. It's a half hour away, but at least I can have him show me, with a bore gauge, where the cylinder is. And if he's spot on, and blames the rebuild kit for not being in spec, I can then inquire as to why he didn't want to get the parts first.

I'm having really bad luck working with outside services on this project. Sandblaster loses my deck, first machinist says things looked "OK" without measuring them, second machinist doesn't "need" the new parts to go ahead and machine.

This is making me sick.

[CC1650Dave]

And now, using Matt's advice that the head of the exhaust valve should be smaller, I measured them up.

Valve 1 – Head Diameter 1.374” – Shaft Diameter .309”
Valve 2 – Head Diameter 1.376” – Shaft Diameter .3085”

So one head is .002 smaller than the other. I would have expected a bigger difference (?) But look at the shaft diameters. They're both below the Kohler minimum spec (.3103) for the intake shaft diameter.

I guess I'd better calibrate my calipers to be sure, but I don't have a calibration block. They're $180 Mitutoyo digital cals, professional grade, and I'm pretty sure they're measuring right.

[Matt G.]

Sounds like you need a new machinist. The ones (like that one) that have an ego think they're too cool to do it right.

I am 99.9% sure you have either two intake valves or two exhaust valves...they should be fairly different sizes. The intake and exhaust valves are two different part numbers. What's odd is the seats look the same size in your picture... That two thou is probably manufacturing tolerance. Are those OEM or aftermarket?

[CC1650Dave]

These are aftermarket valves that came with the "master" rebuild kit.

[Methos]

Dave keep your head up you'll get thru this. I had the same worries that you have and I paid my machine shop $35 to do the reassembly for me. Took all the worry out for me but I ordered all my parts from the machine shop so I couldn't screw it up. Not saying that you have but I was worried I was going to mess it up.

[Matt G.]

A friend of mine at work is rebuilding a 169, and he says the two valves are the same size on his K341, and this is also supported by the parts lookup; the valve part numbers are different, but the seats are both the same part number. I had a 1650 but never had the head off of it, so I wasn't sure what it was supposed to have. I think some of the 14 hp engines also have the larger exhaust valve.

Anyway...since they are aftermarket and presumably weren't marked intake or exhaust, they are probably interchangeable. However, you get what you pay for, and they probably aren't as good as the OEM valves. Your comment about the stem diameter supports my overall distrust of aftermarket parts. Since your aftermarket valves are about 2 thou undersize, you will probably lose oil through the valve guides, particularly if you did not replace the valve guides. Do the valves wobble in the guides? If so, you will have problems sooner or later, if not, you may not. Have you measured the stems of the valves you removed?

If it were mine and I were planning to keep (and use) it, I would have bought OEM parts. I have in the past used aftermarket parts in machines I knew I wouldn't keep, but for my 'keeper' stuff I try to stick with OEM parts, unless it's a trailer queen.

[litlmikeyl]

Dave, I understand what you're going thru with your machine shop troubles. After calling around and getting nowhere or lots of bad answers, as a last ditch effort I went to the shop that I get my Toro push mower parts, who is also a Kohler service center in Blaine (north eastern Twin Cities 'burbs) and he sent me more than 45 min. west to a little machine shop on the other side of the cities. I paid more than most of the guys here on the forum but I'm 95% sure that my K241 is in better shape now than it was new. The gentleman certainly knew his stuff. I'll use him again, no question.

Been running into the same issue with my tractor parts too. My dealer is slowing getting worse in accuracy, price & turn-around time for parts that I need to order and it sounds like others in the area are no better. Like the fellas here say, support our site sponsors not only because the keep the site going, but they're a better outfit to get your parts. They're faster, cheaper, easier, more knowledgeable & almost always spot-on for getting you the correct parts.

Grrr.... It makes me angry. Whatever happened to ol' fashioned honest service? That must be NLA from the manufacturer.

[Sugarmaker]

Dave,
Hang in there! The majority of us need to use other shops to get the speciality work done.
Last 12 hp we rebuilt I had the piston rings and valves in hand when they went to the shop. That worked good and the engine runs well.
Regards,
Chris

[CC1650Dave]

OK, I went to the machinist today with all the parts in tow.

I approached it as being concerned about the rebuild kit I got, and asked him to help me with some measurement.

We rechecked the bore. It was 3.760, spot on ten over.

Then I had him check the ring end gaps. He got .016" on both of them. I have no idea how I was getting .035 and .040. He says that measurement takes lots of practice, so I'll try it again when I get home.

The valve stems were .3095 for the exhaust and .3105 for the intake. I do know how to use a caliper, so mine must need calibration. Have to find a block for that...

I did learn the easy way to tell the valves apart: the intake valve is magnetic, and the exhaust is not. He checked them all out and said everything looks good - go home and put it together.

So I took a measurement wrong, then was mislead by my calipers, and got myself all freaked out. Rookie stuff. I shouldn't be using a caliper for such measurements in the first place, I know that from experience. I need to get a mic.

On the way home, I picked up a pair of ring pliers and a ring compression tool. No one here has mentioned the latter, but I forsee great difficulty getting that assembly back in the bore without one...

[JOHN SCHUTTE]

Excellent news Dave!