Honda GXV140 - something loose in piston assembly

[CM-NC]

Hey!

I am in the process of disassembling the GXV140 engine on my mower to get at the piston, and I have discovered that I can't get the lower cover off - the mounting plate for the blades and spool for the belt (which are welded together) are in the way.

Backstory: The mower has given over a decade of useful service, and just recently I was told that the mower is 'not in a runnable state' and the engine was 'beating itself up'. Being the handyman, I pull the mower and discovered there is a slop somewhere in the linkage between the piston and crankshaft by as much as 15 degrees at TDC and BDC, and as few as 3 at any halfway points between this. Since the piston is still captured by the crankshaft (I.e. it doesn't just push the piston up, it pulls it back down as well), I am assuming that the connecting rod hasn't been broken, and that either the end caps are loose, or there is serious damage where the connecting rod mates the piston.

Problem is, I can't get inside the block - the cover is located 3mm right behind the spool/blade mounting assembly (which itself will not budge).

Can anyone help? Does anyone even understand what I am rambling on about?

Thanks a million!
-CM

 

[robert@honda]

Hey!

I am in the process of disassembling the GXV140 engine on my mower to get at the piston, and I have discovered that I can't get the lower cover off - the mounting plate for the blades and spool for the belt (which are welded together) are in the way.

Is this just a Honda engine, or a Honda engine on a Honda mower?

The Honda GXV140 engine was only used on belt-drive Honda HRM/HRB models mowers with a Xenoy "plastic" mower deck. To remove the engine, you must first remove the blades, blade holder, and blade control mechanism (where applicable); here's a couple of pages from the shop manual:

 

[CM-NC]

Wow, what a fast response!

It is a Honda engine on a Honda mower, the HRB. (You are correct regarding the belt drive and plastic deck) There wasn't any blade control mechanism, though I will give the second page you uploaded a go tomorrow when I retry it! I do want to say that, at a first look at the second uploaded page, the blade holder and pulley are shown separately, and are welded together on my setup (which makes me only slightly nervous about actually succeeding).

Wow, and from a guy who actually works for Honda? What luck! :smile:

-CM

 

[bwdbrn1]

What does the blade holder look like? I had one with a round blade holder that didn't want to budge once too.
Like item #7 in this diagram.

All Years HRM215K4 HXA LAWN MOWER, USA Honda Lawnmower ROTARY BLADE Diagram and Parts

That same engine had connecting rod bolts that had loosened and backed out 1/4 to 1/2", and it acted very much like what you are describing.

 

[robert@honda]

There wasn't any blade control mechanism, though I will give the second page you uploaded a go tomorrow when I retry it! I do want to say that, at a first look at the second uploaded page, the blade holder and pulley are shown separately, and are welded together on my setup

There is a version of the HRB without the blade control parts called the SDA; the blades are mounted to a holder/pulley which is held onto the crankshaft with a single bolt & Woodruff key.

The parts used on the SDA changed a bit; here's a drawing of the early and late versions. Both come apart the same way:


Early version Later version

 

[robert@honda]

Wow, and from a guy who actually works for Honda? What luck! :smile:

I see you are from North Carolina; guess where your Honda mower (including the engine) was built?

Click here and scroll down 1/2 Page

 

[CM-NC]

What does the blade holder look like? I had one with a round blade holder that didn't want to budge once too.
Like item #7 in this diagram.

That same engine had connecting rod bolts that had loosened and backed out 1/4 to 1/2", and it acted very much like what you are describing.

There is a version of the HRB without the blade control parts called the SDA; the blades are mounted to a holder/pulley which is held onto the crankshaft with a single bolt & Woodruff key.

The parts used on the SDA changed a bit; here's a drawing of the early and late versions. Both come apart the same way

Bwdbrn1, you have my situation exactly - it looks exactly like the number 7 part! This is also the same part in the later version of the image you posted, Robert. Forgive me for not disclosing the model #earlier, but it is the hrb2154sda.

Also, that is quite cool that they are manufactured here, though I can't say I am surprised. There are tons of engine and gearheads around these parts. The quality sure is impeccable, this is the first problem this mower has ever had, and I used to mow nearly 1.5 ACRES OF YARD with this baby every other week. Haha I can't say that any car I have ever had has been anywhere near this reliable, that's for sure.

I am about to head out and give it a go, wish me luck! Thanks much you guys.
-CM

 

[bwdbrn1]

Robert can no doubt give you better guidance on the best method to remove that blade holder than I can. But, I'd recommend spraying Liquid Wrench or Kroil around where that shaft meets the blade holder, and let it sit, repeat, and sit, for a day or two, then use a harmonic gear puller to free it up. A bit of heat on the outside of the puller could help too.

Good luck, I wound up having to find another crank shaft for mine, but I'm sure yours will go better for you.

 

[CM-NC]

Robert can no doubt give you better guidance on the best method to remove that blade holder than I can. But, I'd recommend spraying Liquid Wrench or Kroil around where that shaft meets the blade holder, and let it sit, repeat, and sit, for a day or two, then use a harmonic gear puller to free it up. A bit of heat on the outside of the puller could help too.

Good luck, I wound up having to find another crank shaft for mine, but I'm sure yours will go better for you.

Its funny you mention the liquid wrench bit, I was just about to ask how in the world you get enough leverage on this thing to get it off. Worse, if the only thing retaining the crankshaft is the flywheel, then there is the possibility that the least-secured part will free first, which in this case would almost definitely be the flywheel rather than the blade holder.

A new crankshaft??! Geez, I hope mine goes better too.

-CM

 

[robert@honda]

Its funny you mention the liquid wrench bit, I was just about to ask how in the world you get enough leverage on this thing to get it off.

Unless rusted/seized onto the crankshaft, a bit of penetrating oil, overnight soaking and maybe a little heat ought to loosen it enough to pull off without excessive force. The blade holder can be bent/damaged if you get too aggressive with it. If it does get beat up too much, a new one would likely be necessary, 'cause a damaged holder will not spin smoothly, nor will the blades bolted to it.