OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Masport Rocket with B & S Sprint 375

Hello,

I was mowing my laws today when a chatter started in the Briggs & Stratton Sprint 375 on my Masport Rocket. It then blew part of the piston out through the casing. After getting over my initial disappointment I've decide if replacing the motor is a viable option I'd like to do that. I don't know a great deal about lawn mowers but have sufficient mechanical knowledge about engines to replace it.

What I'm curious about is do I have to replace it with the same Briggs and Stratton or are there other options I can take. Any information would be greatly appreciated. How do I determine what engines would fit if there were other options?

Thanks
-Jamie

Sprint 375's like throwing legs out of bed for some unknown reason, plenty of briggs motors up to about 5hp will fit nicely, there is a press fitted boss on the end of the crank that will need to be moved across from your old motor though.

Put a wanted ad up in the wanted to buy section of the forum, I am sure someone will have a second hand unit they will sell, hell I might even have one somewhere.

Or you can go brand new for $150 on ebay, just search for "briggs"

Thanks Joe,

I've put an add up. Will strip it down a bit further tomorrow and post some photos if anyones interested. Although, I'm sure many have seen something like this many times before.

I'm gonna try and get a second-hand motor. The mower came from my old man who found it at a scrap yard. All it needed was some oil and a catcher. Ran pretty well for the most part until now.

Here are some photos for you.




Looks like you were right Bruce. It was the con rod.

distortedunit,

Looks like I keep my money then.

Bruce, What would cause the motor to destruct like that?
I have a 30 year old B&S still going fine.
Were some motors built with weak parts fitted?

cheers gmax

The usual cause is not enough oil in the sump and what happens is that you start to get a slight knocking noise before it snaps and flies through the crankcase.

The conrod is alloy and what usually happens is that it picks up on the crankshaft because of lack of lubrication.

Bruce, Thanks for the explanation, glad i check the oil regularly, perhaps people who don't want to check the oil level should buy 2 stroke mowers!!

gmax