Craftsman LT, Intek engine

[usnavyvet]

I have an 8 yr old 26hp Craftsman lawn tractor, which has eaten an exhaust pushrod. I understand from a previous forum on this website that this is a rather common occurence on that engine. It is apparant that the bent or broken rod is in the bottom of the engine.

My questions are: For anyone of you who have opened up one of these engines, is there sufficient room at the bottom of the engine for that rod to live there without causing further damage? If not, what is the procedure to open up the engine? Is it from the top by removal of the flywheel, or from the bottom after engine removal? If disassembly is from the top, what is the procedure for removing the flywheel? I have maintained the valve lash during it's service time, so what would cause the pushrod to break (and the aluminum intake rod to bend)?

I have used this mower for aprox 150 hours a season for 8 years, so I am
happy with the engine's reliability, but since I can replace the mower for aprox. $1500, I will only repair the unit if I can repair it myself.

 

[skyking]

The typical air cooled engine is assembled from below; the bottom case is held on by small bolts, with a gasket.
http://forums2.gardenweb.com/forums/load/tractor/msg051238537261.html
That forum looks like the best place to get some advice on that engine.

 

[JoeyP]

I've taken apart an Intek v-twin engine a few times. Remove valve covers and verify that the exhaust pushrod (steel=exhaust, aluminum=intake) is actually eaten.

The general procedure is: drain oil, remove valve covers and extract pushrods (label each set left or right), remove governor arm from governor shaft, remove engine from mower, remove oil pump cover and oil pump parts, sand and clean shaft on outside of engine so bottom pan slips off without ruining the bottom seal, remove 10 bolts holding crankcase bottom. Your tappets will probably fall out, so gather those and label as well.

When you reassemble, make sure the camshaft mark aligns with the crankshaft mark. You'll also need a new crankcase gasket and possibly a bottom shaft seal. There is also a governor calibration procedure that is very important. Take lots of pics before.

You can get the service manual from virtually any shop that services B&S engines. I think mine ran $12. It has all the steps along with illustrations and troubleshooting.

 

[usnavyvet]

Thank you for the replies, especially the suggestion to purchase a manual. I'm not sure why I didn't think of that myself...... Sounds like my next project.

Update: while purchasing a manual, I spoke to a couple of local mechanics who were willing to share the process for how they repair this problem. I realize they may be enhancing the problem to get me to let them fix it for me, but I indicated to them as I did above, that I would not repair the engine, if I could not do it myself. Anyway, for what it's worth here are their comments.

1. B&S recommend that the head casting be replaced for this problem. Both of these mechanics install new valve guides and reknurl the casting prior to installing them. They indicate that without at least doing that rework, the problem is bound to reoccur.

2. The price for them to do this work exceeds $500, they both recommended that I replace the engine if I want to keep the mower.
A new motor, delivered is ~$800

3. One recommended, if I did go with a new mower, to attempt to buy
Kawasaki over either Kolher or B&S. I can relate to this opinon, as I currently own a Kawasaki 3100 Mule, which has run faultlessly for 10 years. ~$3200 to replace the Craftsman with a Kaw powered similar mower.

My current plan is to replace the pushrods, seafoam it, and run it as is.... If it dies, I will spring for a new motor.

One last update: Could not get the old engine to run, it continued to bend pushrods. I purchased a surplus motor off the internet. The mower is now up and running.

 

[skyking]

Thanks for posting the detail, JoeyP, and welcome to the forums, the both of you.