L135 Briggs and Stratton V- twin engine removal

[beenthere]

Helped a buddy find and fix a compression release problem on a one-cyl B&S engine given to him.. nearly new engine that had been over-filled with oil.
Starter cord ripped out of the owners hand and had to have stitches to close the wounds.. ?? don't know how but it is the story given.

Tore the engine down.. nothing to lose.

Found a sheared flywheel key so thought that was the only problem. Re-assembled, but same hard pull on the starter cord.

Tore it down again and found how the compression release worked.. There was a very tiny spring that held the mechanism in position to keep a valve open until some rpm's cause it to move (like a governor, somewhat).
Here is a pic of the mechanism and the tiny spring on the camshaft. Arrow pointing to it. Figure the overfill of oil bent that spring so it wouldn't function. Bent it back, and the engine cranked fine and ran fine.

Not at all sure that is anywhere close to the problem of the OP.. just thought it might help to know a bit about the compression release mechanism.

 

[jgayman]

Helped a buddy find and fix a compression release problem on a one-cyl B&S engine given to him.. nearly new engine that had been over-filled with oil.

Wow! Are those PLASTIC cam lobes? Your compression release is a bit different than my 31-series 17.5HP B&S that I recently repaired. However, they both appear to use a spring more suited for a CooCoo clock. Below are some photos of my broken compression release pieces and the new cam.

 

[beenthere]

Are those PLASTIC cam lobes?

Yes, a polymer of some kind. This was the Intek 900 horizontal B&S engine. Agree on the spring size.. but then just needs to allow the mechanism to move ever so slightly to allow that valve to close upon a few higher rpms.
Here are a couple more pics of the teardown.

 

[RandyT]

There have been cases where the polymer camshaft gears and sometimes the lobes will not hold up, but that design has been around for a very long time. I have the exact camshaft with the polymer gear and lobes that a pulled from a push mower engine sitting on my window sill that I pulled from an engine 40 years ago The camshaft most of the time outlast the engine.

 

[jgayman]

Yes, a polymer of some kind. This was the Intek 900 horizontal B&S engine. Agree on the spring size.. but then just needs to allow the mechanism to move ever so slightly to allow that valve to close upon a few higher rpms.
Here are a couple more pics of the teardown.

Wow... nice to see a decent ball bearing to support the crank shaft. I was really disappointed when I tore down my B&S 31-series 17.5HP single cylinder (vertical shaft) to find the only thing supporting the crank was a hole through the aluminum cover.

 

[tomplum]

Wow... nice to see a decent ball bearing to support the crank shaft. I was really disappointed when I tore down my B&S 31-series 17.5HP single cylinder (vertical shaft) to find the only thing supporting the crank was a hole through the aluminum cover.

I could see how it appears that way, but really it is about the only trouble free part of that engine.

 

[Richard001]

Yes, a polymer of some kind. This was the Intek 900 horizontal B&S engine. Agree on the spring size.. but then just needs to allow the mechanism to move ever so slightly to allow that valve to close upon a few higher rpms.
Here are a couple more pics of the teardown.

OK how did you get the cam out without taking the rocker arms off?

Next, what is the solenoid looking thing with the wire on it?

Great photos !

Richard

 

[beenthere]

Rich
As to the cam out, don't recall (2 yrs ago) how that all took place.. but makes me wonder too after seeing the pic.

The thing with the wires to it, IIRC, was an low oil level cutoff which didn't work and was by-passed when reassembled. Made an attempt or two at repairing it, but didn't want to invest any $$ as we didn't know if the second re-assemble would result in a running engine. It did (with the spring fix on the compression release mechanism) run great so we didn't bother with tearing it down to work on the low-level oil switch.

 

[jgayman]

OK how did you get the cam out without taking the rocker arms off?

Next, what is the solenoid looking thing with the wire on it?

Great photos !

Richard

As long as the piston was anywhere near TDC both of the valves would be closed and the lifters would be loose with no spring tension against the cam lobes. As a result you would be able to slide the cam right out.

You can see from the position of the crank that the piston is pushed pretty far up into the cylinder.

 

[Richard001]

Good observation. Didn't think of that.

Merry Christmas