Book for B&S

[sgkent]

Hi - I have a Bluebird dethatcher that is about 20 - 25 years old, that I bought used. The fuel pump and subsequently, tank were bad, but after repair, it runs steady now with new parts. I plan to restore it to an even better condition in the next couple months, and one thing I have not sorted out is adjusting the governor. I think the best solution is to buy a book or find good articles on this engine to be sure all the bases are covered in properly adjusting things on it - governor, speed, valves, etc.. I may even replace the rings because it burns a little oil, although I have read some of the 8hp models have valve seals that wear out. Otherwise I have to search the Internet item by item, to be sure I have the correct procedures. The engine is a white Briggs and Stratton, pull start, with numbers 8HP, 192402 0645 A1 9609 1 91 A . The Bluebird is a model 820, and that company did provide the best pictorial of which dethatcher model they think it is, a C18 but there is nothing on the engine. Any suggestions on an available Briggs book that would cover this model engine?

 

[Auto Doc's]

Go on Ebay and look around. They have lots of B&S manuals in CD and paperback form. This is a little older than 25 years. It's an older horizontal design "flat head" engine, ereplacement. com parts and Jack's small engine.com should have any parts you need for the engine.

If it run well, don't mess with the governor. People always want to mess with them on these engines and there is no reason.

 

[sgkent]

thank you. The RPM is definitaely off but the governor works.

 

[Auto Doc's]

How is it off? Too low? Too high?

 

[sgkent]

Way too low. I had to bend the stop that the high speed limit screw hits to speed it up to 3200. It was down around 2300 at full speed. Turning the stop screw in brought it up to about 2800. I am not the original owner. Found a Briggs page that explains the engine numbers after the last post. The engine code sets September 1, 1996 as the manufacturer date but I can't find any "type" decoder that defines the speed from the engine type on the tag. Bluebird manuals of similar model dethatchers with a smaller engine (5 HP) (but there is a 8hp option) sets the engine speed at 3200 to 3400. I have it set to 3200. I used a Briggs tach, which is the wire that vibrates on the round puck that spins the wire in and out until it oscillates. Audibly, the engine RPM is similar in RPM to the other power equipment I have with Briggs motors. Been around motors all my life, 74 now, but each one is different, and I like to set things up like they were intended to be. Although the deck is rusty, everything is there and it works well.

 

[Auto Doc's]

Way too low. I had to bend the stop that the high speed limit screw hits to speed it up to 3200. It was down around 2300 at full speed. Turning the stop screw in brought it up to about 2800. I am not the original owner. Found a Briggs page that explains the engine numbers after the last post. The engine code sets September 1, 1996 as the manufacturer date but I can't find any "type" decoder that defines the speed from the engine type on the tag. Bluebird manuals of similar model dethatchers with a smaller engine (5 HP) (but there is a 8hp option) sets the engine speed at 3200 to 3400. I have it set to 3200. I used a Briggs tach, which is the wire that vibrates on the round puck that spins the wire in and out until it oscillates. Audibly, the engine RPM is similar in RPM to the other power equipment I have with Briggs motors. Been around motors all my life, 74 now, but each one is different, and I like to set things up like they were intended to be. Although the deck is rusty, everything is there and it works well.

Most Briggs engines run limited at a top speed of 3600 RPM at wide open throttle.

Does this machine have a throttle cable and pull back springs to control the RPM?

 

[sgkent]

Most Briggs engines run limited at a top speed of 3600 RPM at wide open throttle.

Does this machine have a throttle cable and pull back springs to control the RPM?

lever on the side of the engine housing. Once I get the manual I'll have to go thru the whole procedure of setting the carb up right. Since it runs well, I won't be rebuilding it. Might check for vacuum leaks with a carb spray though. Runs and starts really well. The original fuel pump was bad so I had to use another Briggs fuel pump until I could find a NOS one of the original style pump. It is possible the PO played with the carb, and that springs etc have been changed. I have no way of knowing without seeing photos of another similar engine that is original.

 

[Auto Doc's]

Basically, to set the governor: Move the carburetor throttle butterfly to full open and verify which direction the governor shaft rotates when you do that. Then loosen the pinch bolt while still holding the throttle butterfly wide open. Rotate the governor shaft the same direction noted earlier until it stops. Once it stops, tighten the pinch bolt and let loose of the throttle. Fire it up and the governor is now adjusted. If the engine tries to accelerate way too high shut it down and recheck the directions and what you have adjusted.

Like I mentioned earlier the top speed is normally set at 3600 RPM, so you may have to bend the governor spring tab to reach that with the throttle cable, lever set at high without hitting the choke operation. Some governor arms have extra holes, so the spring may need to be connected to a lower hole on the governor arm.

Main jet screw on the bottom of the bowl may need some minor adjustment. Out is rich and in is lean.

Once your high speed is adjusted, then work on getting the idle correct. There is a separate mixture screw for idle as well and it adjusts the same, out is richer and in is leaner.

Basic starting adjustment for both mixture screws is 1-1/2 turns from light seated (closed).

Once you get it running, run it for 30 minutes on full throttle, then shut it down and pull the spark plug to check the color of the electrode. It should show a very light tan on the porcelain. White is too lean, dry/black is too rich for the mixture.

I use the same old school Briggs vibration tachometer as you mentioned, I've had it for 40 years and they work great.

 

[Telesis]

The Briggs service manual you need is the Single Cylinder L-Head # 270962

The good news is you can easily find it here on the interwebs for no charge.

Good luck!

 

[sgkent]

Thanks.