Maybe I paid too much???

This Roper found it's way into my trailer this morning and my wallet got $100 lighter. .....No compression....I was hoping for a stuck valve or something, but no such luck. I took the head off and the piston, she no move. So at the very least the rod is broken. It's a 12 hp B&S. I wonder if the rod out of an 8 hp is the same?....Probably not, eh?

The thing does have a new battery and looks pretty good otherwise.

Yeah...there seems to be a ton of room under there. The gas tank mounts up under there....but still lots of room. Now about a small block Chevy?.....

If this engine is toast, I have a 12.5 B&S twin that may go nicely in there.

I think the rod is shorter on an 8HP, but i could be mistaken.

I tore into it today....The rod was in about 30 pieces.....and the 8 hp rod is smaller all round.

I put a 12.5 B&S twin in it that I have....bolts right in, same sizes shaft etc. I have a question about the carb on this engine though, someone here may know. The carb has a built in diaphragm fuel pump, as the tractor it came out of had the gas tank under the seat. The carb also has a solenoid type thingy, that has an electrical connection to it....The electrical connection pulls a little plunger that seems to shut off the gas. ..Anyone know what this is for?...It doesnt seem to be working, so I will have to buy another one, or grind the tip off a bit so gas can get by it. Here is a picture, not a very good picture....LOL

Not sure, but I know Nate had one of those carb deals... Mabey someone else here knows.

I went on the "big" forum....and Walt2002 told me....

"It is to prevent "after fire" caused by accumulation of unburned fuel
igniting in a hot muffler at shut down. These are relatively expensive
and are not needed, didn't have them at all until fairly recently. Lean
mixtures brought on the "need". Just idle the engine for a little bit
before turning off."

Good stuff to know.

Ah yes, sounds like the MTD we have. It requires about a minute or two of low idle to prevent that "after fire".

My Springfield does that right now because I have to adjust the carb, engine has one speed fits all currently, but it does fire up by revolution 2 so what do I care about the "after fire". I mean if it works it works, why mess with it. I think my solution is to tighten the float needle on the bowl to get lower RPMs.

I say if you don't need it or care, don't worry with it.

As long as we don't blow the muffler across the back yard, eh?.........

I have never had a muffler go across the yard from an "after fire", but that doesn't mean the muffler, given the right circumstances and rust, can't explode. I'm sure somewhere it has happened though, but not here yet.

wvbuzzmaster wrote:

Ah yes, sounds like the MTD we have. It requires about a minute or two of low idle to prevent that "after fire".

My Springfield does that right now because I have to adjust the carb, engine has one speed fits all currently, but it does fire up by revolution 2 so what do I care about the "after fire". I mean if it works it works, why mess with it. I think my solution is to tighten the float needle on the bowl to get lower RPMs.

I say if you don't need it or care, don't worry with it.

Yup its best to leave well enough alone.

a lot had built in diaphram fuel pumps, they had 3 and 4 bolt styles.

Still having trouble getting this heap to run right....It seems to want the choke on to run decent. As it gets warmer, less choke, but I can't open the choke right up or it will stall.....Maybe a vacuum leak somewhere?

Also, I am not sure if it has the right spark plugs...It is a B&S twin I/C 12.5 hp......Anyone know the proper plug? It had 1 Champion RJ12C in it.........

ok....this is Nate's dad.... Nate has gotten outta the reppairin bussiness with me for a spell ... that lil selonid on the bottom of the carb requires 12 volts to it to open the gas valve.... turn it on first before u try crankin the engine.... u can add it to a single lil seperate switch that u make sure u turn off just before u shut down the engine....I'd do no mods to the carb to by-pass that feature......

oohh.... if the new install for the engine has the gas tank above the carb...u can delete the fuel pump & go straight to the carb ...I'd install a fuel shut-off vale too...I do that on all my repairable mower that have tank above the engine leval...

the rod on the bigger B & S engines like from 12 to the 16 hp single cyls all appear to b the same rod....pistons r bigger dia.. tho from wat I've seen

u may try takin the carb off & givin it a good cleanin....blow it out with air hose..... & run a real thin wire thro the passages.....(a wire from the paper wrapped twisty tie works great) watch out with the air....the gas inlet valve may have a small rubber seat that u can blow out & lose & never know it..

ok...gotta make a correction again......not delete the carb in last post....but instead delete the fuel pump....lol

musta been a senior moment....lol

Glad to know I'm not the only one that has blown the little rubber seat out of a carb with a blow gun.

Thanks Whirly...Cleaning the carb did work.....I sold the tractor to a buddy, been working good.