Group 12/PDR

Causes for Corrective Action

It is necessary to evaluate our teamwork and project as we progress. Thus far, everything has been running smoothly, the group has met every deadline, and are working together to form a strong team.

The only aspect that could be altered is one of our meeting times. Not all of the members can make the meeting Wednesday at 5PM. We decided to make Wednesday from 3-4PM a possible meeting time as well. The frequency and length of these meetings will depend on the complexity of the approaching gate. Currently, the group is working well together and accomplishing set goals.

We encountered minimal problems due to the extensive technical knowledge of select members of the group. Their strength in these areas has allowed superior foresight into the possible technical problems of the disassembly process. This foresight saved time, and allowed the group to allocate more time to answering problems for the gates.

Product Dissection Plan

Disassembly The disassembly of the leaf blower will be explained in the chart below.

Difficulty Rating:
The difficulty of the steps is indicated in a scale of 1 to 5 and indicated by a bold number enclosed by parentheses. The lower the number, the easier the step, and the higher the number, the harder the step. A harder step may require more insight to possible problems, more sophisticated tools, more time, and/or more man power. This scale assumes a basic understanding of mechanics and basic experience with gasoline engines. A person with “basic” skills should understand how an engine works, and have taken at least one apart in their lifetime.

Disassembly

#	Name	Difficulty	Description	Image
1	PLASTIC NOZZEL	3	Loosen the blower bracket which can be done by loosening the bolt clamp enough to allow movement in the nozzle. Gently pull the black nozzle out of the green housing.
2	PURPLE PLASTIC CARBURATOR HOUSING	1	Remove the two screws (using a flat head screwdriver) that secure the purple plastic carburetor housing on the left side of the leaf blower (when looking at it with the nozzle point away from you). This will immediately expose the air cleaner which is attached to the front of the carburetor.
3	INNER PLASTIC HOUSING ATTACHED TO CARBURATOR	2	Loosen the two screws securing the inner black plastic housing that is on top of the carburetor.
4	PURPLE PLASTIC MUFFLER HOUSING AND ATTACHED HEAT SHIELD	1	Loosen the two screws that hold the muffler housing and heat shield to the engine. The heat shield is attached to the back of the purple plastic housing, meaning that once both screws are removed, both pieces will come off the engine in one piece.
5	SPLIT MAJOR PLASTIC HOUSINGS	4	The first step is to remove all screws (eight total) that hold the two pieces together. Be sure to remove all screws, or difficulty splitting the leaf blower apart will be encountered (as was in our disassembly). Furthermore, removal of the muffler is necessary in order to allow the right hand side plastic housing to be separated from the engine. After opening up the blower cover on the bottom of the leaf blower, the two major plastic housings should split down the middle and fully expose the engine.
6	CARBURETOR REMOVAL	3-5 (depending on how hard the rubber is adhered to the brass)	Now with the engine exposed, first component that needs to be removed is the carburetor. To remove the carburetor, one needs to pull the two rubber fuel lines off of the brass tubing connected to the carburetor. A small flat head screwdriver may be useful to pry the tubing off of the brass.
7	FAN BLADE REMOVAL	2	After removing the carburetor, the fan blade (that is on the shaft of the engine) must be removed. A ½ inch socket can be used to remove the self locking nut and double flat washers. The fan blade must be held to prevent the engine from turning when loosening the nut.
8	RECOIL	2	Behind the fan blade is the recoil (used to start the engine) and must be removed using an Alan wrench on the three mounting screws. The recoil was not disassembled further for two reasons: the internal workings of the coil are rather simple, and the spring inside is not very easy to reset
9	MAGNETO	2	Near the engine shaft is the magneto and wires to the spark plug. Six screws must be loosened using the same 4 mm Alan wrench as the outside screws.
10	COMBUSTION CHAMBER	3	A 3/16” Allen wrench was used to loosen the main bolts securing the combustion chamber. This assembly lifted off, revealing the piston, crankshaft, and connecting rod. This allowed the piston and its connecting rod to slide off of the crankshaft. Note: The only portion of the main engine was not disassembly was the crank shaft and main bearing. The amount of effort required to do this outweighed the technical benefit.
11	CARBURETOR DISECTION	2	A Phillips head screwdriver was used to loosen two bolts which held the primer in place. Then, the bottom plate of the carburetor could be removed.

Problems Encountered:

o Problem- As the black plastic housing was being removed, it was found that the same screws were responsible for attaching the carburetor to the engine.
o Solution- Remove the carburetor as well

o Problem- If the housing does not come off, look for a screw at the top of the handle.
o Solution- Remove the screw in the handle that is recessed in the housing. It is very hard to see, and can easily be overlooked. It is also important to remove the spring from the blower cover after the plastic housings are separated. The spring is in compression and will shoot off if not removed before setting the housing down.

o Problem- Upon inspection of the carburetor’s internals, it was noted that the needle and seat were sticking. This is likely the cause of the engine’s difficult starting.

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