I've got an old Murray 46" with 18hp B&S that's probably at least 10 years old. It's very difficult to crank, even with a new battery & battery cables. I've read the threads about checking the valve clearance and will be doing that next weekend. I have to take the hood off to get to the engine numbers, so I don't have any details yet.

What puzzles me is if I spray a little starting fluid into the carb, the engine will spin like crazy before it fires. Is it logical that this fluid would make that much difference?

Thanks,
Dave

More info: It's an L-head I/C horizontally opposed twin. I haven't been able to find any numbers on it yet on any of the shrouds or the parts of the block that I could see easily. Maybe it's under the dirt somewhere. I did find a date code on the Murray frame of 2172. Any ideas on how to intrepret that? It certainly is well preserved if it is 36 years old!

Wish it were an OHV as I'm not sure I want to get into all the work involved with removing the heads, getting new gaskets, getting a valve spring compressor, etc.

Really puzzles me about how well it cranks with a shot of ether, though.

Thanks,
Dave

Really puzzles me about how well it cranks with a shot of ether, though.


Dave,

That's because the ether is more volatile than fuel. The engine doesn't have to spin but just enough to spark one time then it fires off, It doesn't have to crank over and pull the fuel through the carb and intake into the cylinder.

Your model numbers will be stamped in the left hand (sitting in the seat) cylinder head cover just below the spark plug.

This being a Murray with most likely the battery under the seat it is important to maintain a good battery in this unit due to the length of the cables running to the front.

It has been quite a few years since I have had to do anything with the valves on one of these L-twins, A common problem with this style unit is carbon build-up on the pistons/heads which could increase compression and dragging starters due to the long cables. A valve adjustment on these rarely needs to be done, They are normally good for the life of the engine.

I would suggest checking the battery and ALL connections including solenoid, Maybe a starter tear-down to clean and lube making sure the drive gear is in good shape. Then move to a cylinder de-carbon valve check should the previous mentioned doesn't solve the problem.

Good Luck

i agree a starter tear down (bushings in the ends of the starter will wear out) then it turns very hard or not at all also the starter gear drive sometimes will stick uop into the ring gear needs WD 40 or the like there

Just a FYI -- had to take the shrouds off the engine earlier this summer. Decided while I was at it to disassemble the starter motor. Cleaned and lubed the bearings/bushings and blew out the dirt. Works like new now! Thanks for everyone's suggestions.

Dave