Introduction: Oil Injection PWK28

First instructable I've made so hopefully it's understandable for the community! :)


Needed a carburetor for my Yamaha RX135-clone winter project,and had the PWK28 stowed away.

The PWK was not prepeared for oil injection so I wanted to see if I could make it...

It uses a 3mm id hose from the pump to the carburetor that is why I've used the parts I have in this instructable.

On other application different size of threads, connectors and hoses could apply!

Safety first!

Small chips can get in everywhere and is really sharp, so use PPE

* Gloves

* Safety glasses

* Vacuum to remove chips

Parts needed

* Clean carburetor (perfect chance to clean it well)

* Fittings - m5 thread with o-ring, to 4mm hose, i also added an elbow fitting. since I had the parts laying around.

It would be more ideal to just buy an 90 degree elbow...

* Center punch tool

* Batterydrill or drillpress with varying sizes of drillbits (I used 1,5 - 2,5 - 4,2mm)

* M5 thread tap

* Non-dissolving tissue, lubricant

Step 1: Mark and Center Punch

Draw a cross to mark where to drill.

I used a simple "spring charged" center punch.

Step 2: Drill and Threads

I filled the carburetor with a non-dissolving tissue to avoid chips falling into the carb

I used a small amount of wd40 (all kinds of lubricant would help, but my experience is that wd40 is excellent for drilling or grinding/milling aluminium), and held a vacuum close to get rid of all the small chips.

Drill the hole carefully, starting with a small drill and increasing in several steps.

After the hole have been drilled, make the threads with the tap.

Carefully remove the tissue making sure all the chips is removed.

Inspect the carb for any chips inside, then clean the outside, taking care that nothing falls into the starter/choke hole.

Step 3: Add Fittings for Hose Connection

Measured the pipe end on the threaded fitting and cut of 5mm to reduce the build height.

Make sure that you leave enough space to operate the quick release mechanism on the connector.

Screw the threaded fitting onto the carb and thighten just enough.

Since it has an o-ring it will seal up against the carburetor.

Mount the elbow.

Step 4: Finished

Recheck that the carburetor is clean for chips and other things.

The carburetor is now ready to be installed back into the bike, and connected to the pump.

First Time Author Contest 2018

Participated in the
First Time Author Contest 2018