Warning: Long w/ a lot of jargon thrown in for fun! :p

I have talked to my local Honda warranty service center...they didn't even know what I was talking about! So much for skilled technicians in an era of throw away!

I am looking for the crankshaft run-out specification on the business end of a Honda GCV-160 engine. It is on a Honda HRR-2163TDA mower. Can anyone quote me what Honda says is acceptable run-out in the power out end of this vertical shaft engine?

Yes, it is true, I hit something - with the mower. It was a loose piece of Madrona (wood) about 2 to 2-1/2" diameter, maybe 5" long. After restarting there was more vibration than before.

I have purchase new blades, real OEM, for the mower. It is one of their Quadra cut mowers. I have not mounted the blades yet. The blades attach to an adapter flange that is a sleeve that slides over the shaft and is bolted to it.

I am an engineer (aeronautical) with race engine building experience. Before I started just throwing parts at it I set up to diagnose the problem. With the blade adapter off and the shaft wiped clean (mower only has about 25 to 30 hours run time) I mounted a magnetic base to the underside of the mower deck.

With a 1" travel gage, I measured the run-out right at the end of the shaft at about .006" TIR. I marked and labeled the shaft at every .001" indicated run-out.

I then change from the travel gage to a dial indicator (much higher resolution.) With the dial indicator mounted, measured the shaft at the same place, about 1" further up the shaft, just above the keyway towards the deck and also just below the dirty area that is only about 1" below the deck where the drive pulley for the self-propelled take off ends.

With the dial indicator I measure about 5-1/2 thou (.0055") TIR. This is about the thickness of a sheet of paper in all three positions along the length of the shaft. This is not indicative of a bent shaft - to me. I would expect to have larger TIR at the far end of the shaft and smaller readings towards the bearing/mower deck.

I am thinking that the shaft is not bent, rather it is not completely round. I'm thinking that the shaft was round when first turned but when the 2 keyways and the full length slot were cut that the metal stressed/moved so that though the centerline is probably concentric w/ the far end and probably the bearing flange area is probably round, the end of the shaft w/ all the extra machining is probably not exactly round.

Anybody agree or disagree with my theory? What are opinions regarding running w/ bent shaft if bend is only .006" total? And of course my original question, does anyone know what Honda's actual spec is on this?

If you put up with all the junk I wrote, my hat is off to you and your perseverance! Thanks to all that look at this and a special thanks to all replies!

Thanks,
Tom

I don't think your crankshaft is bent either, and if it is I don't think it's enough to make it vibrate much.

If your mower has the steel blade adapter, it could be tweaked enough to cause the blades to not be level, this would result in a vibration.

I could not find the information that you were looking for either, but here is a dimensional drawing of your crankshaft, I don't know if it will help you any.


http://www.hobbytalk.com/bbs1/attachment.php?attachmentid=61840&stc=1&d=1214613379
N3_type.pdf

Hi 30YearTech,

Thanks for taking the time to read and reply. I had to order the welded up blade adapter assembly and won't have it 'til the end of next week. I haven't taken enough time to really look at the adapter weldment and see if I can make reasonably accurate measurements or not.

I think I'll try a couple of simple measurements and then put it back together with the old adapter and new blades and see what happens. If it still vibrates then wait for the new adapter.

I did get a very fast return call from a voice message I left yesterday from an authorized Honda and Kohler small engine dealer. He has the crankshaft and though he said that Honda intended this as a throw away engine that the crank replacement wasn't bad to do. His web site is 2lcstore.com and they're up in Utah. A real nice guy so I thought I'd put a plug in for him!

Have a great weekend,
Tom

I am posting on another thread my attempt at changing the crank on a gcv160. http://www.hobbytalk.com/bbs1/showthread.php?p=2430818#post2430818

It wasn't bad to remove and I expect won't be too bad overall. I was worried I'd need to reseat rings and have to buy more tools. Other than a gear puller and a torque wrench, you shouldn't need anything special. That is, provided you only take apart what you really need to.

If it comes down to replacing it, look at the thread and by then I should have posted some picts. My parts are due in Monday 7/7/08.