OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Rover Engines Rover Quickstart Deluxe Briggs engine

This mower had oil deposits all over the deck, I gave it a clean including the air filter which also had a fair amount of oil on it. It seemed to be coming out of the muffler. I then checked the oil level and sure enough there was too much. I took out the excess oil and the mower starts first time but it runs inconsistently and overrevs for a few seconds before stalling, it does run ok for about a couple of minutes before overrevving. The mower has a float type carby and I did take the bowl off and gave the jet which holds it on a clean. I don't normally work on this type of engine, what would be your next step?

Tiger, We would need the model and type numbers of the Briggs so we can see what you're working on.

Since sounds like the oil was polluted with gas, you should do a complete oil change change and not just out part of the oil. If you don't the remaining oil will still have gasoline in it which will vaporize as the oil heats up and can cause problem of over-acceleration as the engine will suck the fumes back into the engine via the breather.

Also the diluted oil can cause the piston rod to seize the the crankshaft journal from aluminum transfer. Once this transfer starts it will continue until the rod snaps. It takes time to develop as there is some lubing still going on so initially no damage is done just happens the longer you run the diluted oil.

As for the float valve and seat. I am thinking that you would have an all metal valve and a rubber seat. If so at least install a new rubber seat but most kits as both. Also the seat can be installed backwards; the groove side goes in first.

Hopefully you know it will smoke for about 10-15 minutes as the oil in the muffler burns off. Just watch out for the fire trucks.

Thanks AVB, the id on the cowling is 12F802-1975-B1-02071959. Am wondering if should do a complete carby clean, btw the smoking was bad at the start, it seems to have reduced the last couple of times I have started it up.

G'day folks,
Righto, that engine is a 190cc/12ci Quantum series, made on 19 July 2002.
The IPL for it can be downloaded from http://www.thepowerportal.com/ipls/ipl.htm?md=12F8021975B1_IPLURL_LO.pdf

I take it that it has the flat panel paper air filter? If that's oily, the engine will have run rich. And as AVB suggests, it's very likely that the oil in it will have become diluted with fuel.

This will have caused the high oil level, and some of the excess will have blown through and ended up in the bottom of the muffler. Hence the leak onto the deck, from the muffler seam. As AVB says, it will take a good run to burn the oil out of the muffler.

And do change the oil; about 500mL of SAE30 monograde oil is about right for these. Have never had one take a full pint without being overfilled.

The Walbro carbies on these are pretty good units; if there wasn't a noticeable amount of muck in the bottom of the bowl, it shouldn't need a full cleanout. Unless there were signs of water in the fuel. AVB has the seat type [soft Viton rubber] right; these get hard with age, and will then leak.

If you have to take the carby off, you might just as well put a full kit through it - P/No 498260.
That includes a needle and seat, as well as gaskets [and a few bits you won't use, that suit other models]. The aftermarket kits are cheap on FleaBay.

Thanks Gadge for that info. I took the whole carby off last night and cleaned it thoroughly just to rule that out as a factor. The mower started easily and then performed exactly the same as it had. It sounded like it was gasping for air so I ran it for a couple of mins without the air filter and it runs perfectly. I did wash the old air filter with detergent and then with petrol but obviously it's too far gone. Thanks to all, I will give it another run but I think I've saved this from the scrapheap.