Export thread

Hi Troops,
Over that last few weeks my Scag Tiger Cub has developed an engine oil leak. Today I removed the engine and checked where the oil is leaking from.
In the pic with the blow gun tip is pointed, the engine base gasket is where the leak is located. It is a metal gasket and when I blow air in this area, the crankcase vent valve whistles. I won't be able to get into the engine today, but for sure I need to clean it up before I do!
I was looking at the parts manual for the engine that has replaced this engine and I see where there has been a change done to both the crankcase and the oil base. When I get into this engine I will call Briggs to see what they recommend. This was a new repower engine in March of 2013 #49M977-1036 and has only 450 hours on it. Replacement engine is #49T877-0004-G5
As you can see in the pics, the clutch is wet with oil!!!
Fortunately I have a backup tractor:tractor: with a 48" deck and collection system to do my lawns while my Scag is in dispose!!!!
About a year ago I gave away my parts cleaning machine figuring that I would not need it anymore!!! Oh well!!!
The plywood that you see in the pics is the covers for the pit in my garage, nice to have it!

Hi Troops,
Today I removed the oil sump from the engine and found two conditions. Most of the 10 sump bolts were loose and a small part the sump gasket between two sump bolts had moved inward into the sump area causing the oil leak.
My local Scag dealer had the new sump gasket kit in stock, I bought it and I have reassembled the engine. I added oil and primed the oil pump by turning the engine by hand until oil flowed out of the filter adapter, installed a new filter and continued to turn the engine. I have a pic that I will post tomorrow that will show how much the gasket moved. I now need to cleanup the machine and reinstall the engine.
The gasket in the kit was slightly different than the original gasket as it was wider in most areas. New stretch bolts are supplied in the kit and the torque is 300 INLBs whereas the repair manual spec is 200 INLBs. My observation of the engine is that where the bottom of the V of the cylinders is there is expansion from heat that spreads the engine block in that area and contraction when that area cools. This movement may have caused the gasket to have been chaffed and moved. The somewhat loose bolts added to the problem. Just my spin on it from the markings on the mating surfaces in the movement areas. The instruction sheet says to install the gasket dry which I did, but I really would have preferred to have used a high temp gasket sealer.
Tomorrow I'll put it all together and run it.
Later
Mad Mackie in CT:laughing::biggrin::smile:

Hi again Troops,
The engine is back together and installed on the machine and running. Still need to install the clutch and as I have a new clutch in my stash, I'm going to install it as the bearings in the old clutch are noisy and rough just turning it by hand in addition to the fact that it got lots of engine oil on it from the leak.
Here are some pics, two of which show that the gasket had moved inward causing the leak.
If any of you do this job, make sure that you correctly install the oil pump drive shaft. With the engine upside down and remove the oil sump, the pump drive shaft will fall out of the pump. I wiped it dry and applied a dab of sticky grease to hold it in the pump while installing the sump.
Later
Mad Mackie in CT:laughing::biggrin::smile:

My Scag Tiger Cub is back in full operating condition. Now just 2,000 + or - bushels of leaves to cleanup between now and early December!!!
Just gave it a large dose of Sea Foam cough medicine, fueled it and inspected the areas that I did maintenance, no leaks!!:thumbsup::dance1:

Mad Mackie in CT:laughing::biggrin::smile:

Mackie,

Nice to come full circle from a real problem to a nice clean fix. Nice photos. I wonder if this has been seen in other motors of this series or if this is just a once in a blue moon occurrence. Lastly, roughly how many hours do you have on that engine?

Great job ........ Rhett

Didn't you recently repower with that engine? I know I've read some posts where you praise it. Heck, it still sounds like a good engine to me.

This was a repower in March of 2013. Having had problems with two Scag digital hourmeters and installed an analog meter, the best time estimate on this engine is 450-480 hours.
This is a 44M900-49M900 series engine, the first with the beefed up block and Cyclonic Air Filtration System. From the comments that I have found on line, the oil sump bolts may not have been torqued enough during assembly which has caused the gasket problem. Briggs has come out with a replacement gasket kit that includes a larger gasket and 10 new bolts torqued to 300 INLBs in 100, 200 and 300 INLBs steps in a cross pattern similar to how an engine cylinder head is torqued. The new bolts are stretch bolts with a dip of Locktite on the threads.
The only service manual that is close to this engine is the Briggs Intek V-Twin Cylinder OHV Repair Manual. The oil sump torque specs in this manual are 200 INLBs.
It is an easy job to do, but the engine has to be removed from the machine and carefully drained of oil or it can get messy.
I installed the new clutch that I had in my stash as the original clutch bearings were rough and noisy plus it had oil from the leak dripping out of it.
Other than the oil leak, this engine has performed great, lots of power and better fuel economy than the Briggs 26 ELS/Intek engine that it replaced.
The 44M900-49M900 engines have been replaced with 44T800-49T800 series engines, the most recent productions of which have a different oil sump and cylinder block.
Mad Mackie in CT:laughing::biggrin::smile:

The base Intek in my dyt4000 shed several of its sump bolts. With the resultant lack of seal and (normal) crankcase pressure several pieces of the pan gasket blew out, leaving a "step" in the sump to pan interface , even when retorqued. The gasket is paper so weaker than the metal one described. Another feature which suggests factory acknowledgement of the loosening of the pan bolts is how they remain "captured" after backing all the way out. Proximity of the frame to the loosened capscrew keeps the bolts standing on their heads and not "missing in action." I include regular torque check of these bolts. Of course once the "step" is created an owner must live with the weeping oil or disassemble. Price of vibration IMO.