Knock Knock, Who's There GCV190

[Fordiesel69]

I just harvested a crankshaft out of GCV190 that had a broken magneto mount on the engine block. Inside the engine was signs of galling on the crank journals. There was aluminum from the flywheel and base journals imbedded into the crank. I soaked in acid all night to evoporate the aluminum off the steel, then polished them with crocus cloth. As you well know crocus cloth will not remove metal it just polishes the journals.

The rod to crank clearance is 0.0015 which is not fifteen, its one and one half thousands. This is spot on. One spot bordered on .002 which for a small engine is fine for splash lube.

However here is the bad part. The flywheel and base pan journal were galled and measure .002 less than a good crank. Is this the source of the unloaded knocking? When you enguage the blade, the knock quits.

BTW, this engine in the pic is a very low hour unit, the crank had to be replaced because it was bent and I needed it to be a roto stop. The engine I harvested the crank out of was a high hour unit with a cracked deck/

 

[apwillard1986]

Without hearing it in person it is hard to know. It could be the clutch. I am not familiar with how the newer style rotostop works but the older style had bushings and when they wore it would knock a bit.

If you have access to some plastigage I would measure the rod clearance to the replacement crank.

 

[Fordiesel69]

The rod clearance was .0015 which is one and one thousands of an inch.

I removed the roto stop clutch and drive belt and tried again. It knocks unloaded from the flywheel area. As soon as you install the roto stop and enguage the blades the knock goes away. It then will knock on DECEL when the clutch is enguaged like the crank is slapping in the block. I wonder if I can install a bearing on the flywheel side.

 

[wpod]

Buy a new engine .

 

[Fordiesel69]

No fun in that!!!!!!!! Im building good mowers out of junk mowers.

 

[Fordiesel69]

I ordered a new crankshaft. To much slop up on the flywheel bearing journal that wasn't there on the bent crankshaft. Have times changed with metal alloys. The cranks are so soft now they must wear equal to the aluminum.

I can visually change the air gap on the magneto by just simply grasping the flywheel and moving it back and forth. the upper crank journal was NOT worn at all on the engine block due to its low hours. So with the process of elimination the carnk I harnvested must be worn more than I thought. I must have measured it wrong.....

 

[Fordiesel69]

I little heads up.......Make sure when you are calling in part#'s you use the phonetic alphabet. One week of waiting down the drain.....

I needed a DW = Delta Wiskey, they ordered me a BW = Bravo Whiskey

How clever of Honda........
DW= GCV190
BW= GCV160

06131Z8DW50

 

[Fordiesel69]

Got the replacement crankshaft installed and found that I measured it wrong. It was worn seven thousands out of spec on flywheel journal. Good thing I did not run it long. Runs perfectly quiet now. Almost like it is brand new.

Enjoy the photos

 

[Amunoz24]

Got the replacement crankshaft installed and found that I measured it wrong. It was worn seven thousands out of spec on flywheel journal. Good thing I did not run it long. Runs perfectly quiet now. Almost like it is brand new.

Enjoy the photosView attachment 29367View attachment 29368View attachment 29369

I must have the exact same problem .I got a brand new hrr216 with the roto stop from the homedepot returns. And at idle it sometimes makes a knocking sound once I rev it up and engage the blade it goes away . It thought maybe it was the roto stop making noise

 

[danez_yoda]

a little JB weld will quiet her down.

 

[meep]

I can’t imagine that .007 difference at the flywheel bearing is enough to allow visual movement at the flywheel. The housing bearing/bushing might be worn or egg-shaped too?

 

[Fordiesel69]

Amunoz24,
Yours is normal, and is amplified by having a light flywheel. Mine sounded like a single cylinder Hatz diesel. It was so bad that nobody would have been comfortable using it. If your engine starts smoking and knocking once you put about 20 hrs on it, then you know the customer returned it because they forgot the oil and knew about it. If all is well after 20 hrs and the sound is the same, then welcome to owning a honda for life. They are a little noisy but will last forever with maintenance.

The Honda "rubber band" engines get a spotted reputation as they will not tolerate any neglect. Elimimate the neglect from the equation, and they will outlast the mower deck. Honda had and probably still has a terrible air filter cover that falls off. People mow over it, and just run without an air filter, and consequently ruin the engine. Another area of concern is the upper flywheel crank journal. Lack of oil changes allows metal particles to build up, and cause galling of the journal. This will allow enough clearance to cause the flywheel to rub the magneto. When this happens severe enough, it can snap the magneto clean off the engine block.

Meep,
The crankshaft did not tell the entire picture of the issue. The crank was indeed worn out of spec. The engine block was also worn slightly accounting for a few additional thousands gap making it visual and audible. The new crank fixed it 100% and it sounded like all over GVC190's.

 

[meep]

Right on, very cool!

 

[Exhaustgases]

And the cost of a new crankshaft is? Parts for small consumer items almost cost as much as a complete new unit, be it small engine related or appliances. Unless said parts are offshore copy's.
Since original BS cranks can be a bunch over the 100 mark I bet the honda's are like half or 3/4 the cost of a new engine, just not worth it.

 

[Fordiesel69]

Well the mowers can be obtained free, or maybe $20 with bent cranks. The replacement crank was about $32 with tax and it was a genuine Honda. My time was free as during covid lock down there was nothing to do anyways. If you were doing this in a shop it would most likely not be worth it.

Keep in mind the HRX217 mowers are $700 new

 

[Exhaustgases]

Yeah just looked and they don't cost too much. It was a good choice then. No reason for small engine parts to be as high as they are, they spit them off hundreds per hour. I'm guessing the cost to manufacture a lawn mower engine is about $10 per unit at the most, everything else is profit.

 

[Fordiesel69]

Small 2 strokes are where the highway robbery really is. $40 for a small 21cc piston? Or my favorite...... $137 for a small Shindaiwa T270 crankshaft. And yes the trimmer is that impressive that someone may need to buy one instead of scrapping the unit.

Honda's weak link is their transmissions, and those are not affordable or fun to swap out. The plastic ones cannot be short bailed but the hydros can.... A typical homeowner would never know this.