Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Existing motor is a B&S 3.5HP Model 92905 Type 1825-01 Code 77083004.   I have tried the B&S site and could not find a correct replacement.

Any direction on how to research for a direct replacement engine would be greatly appreciated.  I have had the mower for 16 years, I bought it used

it has been a great mower but the engine is pooped.

John- Sounds like you have an engine without the blade brake mechanism. Good for you. It also sounds as if the carb  linkage shorts out the ignition when you go to low motor  just as the Briggs did. One thing occured to me -did you check to make sure the shaft length and diameter are the same as the Briggs? If so you are almost there. Taking the blade adapter and the pulley off the Briggs and putting it on the Tecumseh is the next hurdle. My first Tech had key way in the shaft but my blade adapter had set screws I put the adapter on and marked where the screws contacted the shaft. I then filed some flat spots on the shaft where the screws from the adapter contacted it. As I said I did this a while ago and it is the second repower so I forget if the  blade adapter had a key as well. I also remember having a hard time the first time getting the adapter off the Briggs.

If memory serves me  on the second repower I went to the mower shop and bought an updated blade adapter because I didn't want to go through the trouble of trying to get the old one off. It can be done but it is a pain.

Marc    

mml4 wrote:

Marc, The shaft dia. and length are exactly the same on the old Briggs and the new 840.  My 840 has a keyway the full length of the shaft and at 90 degrees from that full length keyway are two individual slots for woodruff keys.  I have already fitted the blade adapter with woodruff key in the lower of the two individual slots and it fits perfect.  The only problem left is removing the old engine pulley from the Briggs.  It has a set screw holding it and it is stripped out.  It may also have a woodruff key can't tell yet.  I may have to get a new engine pulley if I can't get the set screw out.  Marc, I can't thank you enough for all your help, I really appreciate it.

John

 

 

John- It's been my pleasure!! I'm glad the shaft is the right size. Wait till you get that puppy running. You are not going to believe the difference between it and the Briggs. If you can get your hands on a tach try and set the governor to about 3550. I don't mean to lecture but be careful about the fuel- I can't tell you how many times I almost forgot to mix in oil . In addition I found the Snapper blades to be much better than the after market. They are much lighter and my engine runs better . Worth the extra $ in my opinion. 

Getting the old pulley off after all those years is going to be tough-probably not worth the effort..

Please let us know how you like it.

Marc