What you see on the right is the final version of a gas engine drop in motor leg system for the standard hobie cassette using a Honda 4 stroke 35cc engine. The PA version is built the same way, but utilizing the larger cassette with a non-branded 4 stroke 53cc engine. This has the upgraded twist shifter, rubber cable clamps and all of the parts listed below. If you are interested in a complete setup, supplied with or without an engine, please inquire. These are all custom made.
These are the parts needed from the original Kayak Buddy leg kit that you can order to achieve this simple version to propel your kayak. Leg kit can be purchased on the order page, click here.
1. Tiller arm clamp and tiller arm
2. Main tube, gearbox, bushings, and driveshaft
3. Upper and lower clamps
4. Clutch housing
5. * Additional - Cast aluminum prop with 10mm collar
6. * Additional - Original factory drive block off for drive
7. * Additional - Smooth or polished stainless steel cross
bar 1/2 (6 inch)
8. * Additional - 2 - 1 inch stainless hose clamps
|Instructional Set: (As more information and updates are available, they will added below)|
|1. The first thing you want to do is strip the leg of all of your parts with the exception of the gear box and vertical drive shaft tube. Everything else put to the side.|
2. The block needs to have the upper and lower tube holes drilled with a hole saw bit. You need to get as close to 26mm as possible, since the tube is metric. I recommend finding the center between the rear of the block and where the plastic ears are. This is also where the 6-inch stainless bar will be positioned. Note: the lower or bottom of the block is smaller length wise, so you must take this into consideration when cutting the holes. You only get one shot at this.
3. The ears of the block need to be cut off and drilled out and the 1/2-inch bar inserted. I added only hose clamps on each side inside to keep the bar in place. If you drill a bit smaller where the original ears were, you can push through firmly and add the clamps. Just as a note, before you permanently place the stainless bar in the cassette, you need to test fit and round-off the edges of both sides of the bar to replicate the cassette ears. Only slight grinding is needed to produce the rounded corner in order to obtain a snug fit.
4. Once the bar is in, it's time to add the plastic collars found in the clamps picture above. This is for the upper and lower hole on the block. You are to then put the driveshaft tube and gearbox through both collars with the block and add the large clamp on the top and the smaller clamp underneath and snug the collars after you slide it down securing the block. (reference figure 1 below)
5. Place the assembly in the mirage drive hole and add the clutch housing on top. You can keep it loose. Now, you need to measure how much of the tube you want to cut so that you still have around 4 inches of vertical adjustment of the gearbox. You need to figure in the engine height, so it sits safely on top, but not too close to the inside deck. This is a personal preference. Available driveshafts measure in at 17.75 inches for standard Hobie mirage drives.
6. After measuring, pull the drive shaft out and cut with a tube cutter (disassemble pieces from above first), but be careful of the 3 bushings inside. I would test the driveshaft height and mark the tube. It should sit flush with the top of the tube. If it is a bit lower or higher based on your cut measurements, you can adjust it with the clutch housing a bit when you slide it on. You will need to reuse the upper bushing as it will be pressed down into the cut tube. I use a ratchet extension with WD-40 to slide them equally within the tube length. This limits driveshaft vibration.
* Step 7 is the most difficult part of the build. Please do not weld to the clutch housing.
7. The driveshaft needs to be cut and a 9T spline added to that cut side. My recommendation is to not couple two cut ends or weld the shaft unless it can be stress tested and balanced. High RPM will destroy the leg if the shaft is not straight and aligned. You have been warned.
8. Add the tiller arm collar and clutch housing (figure 3 and 4)
9. You will need to obtain the correct angle of the tiller arm and cut the remaining that sits behind the clamp and re-insert the black cap. In the model above I left the full length with a custom shifter to make it easier to adjust the throttle.
10. As far the throttle is concerned, I custom make shorter versions with stainless cable and billet connectors with grease boots. This allows for longevity and faster throttle response. Click here if you need one made.
11. Now, when it comes to the propeller, you will need a 2-blade cast clockwise rotating aluminum propeller (figure 9) that has the hub that can be attached to the drive pin. The hub will need to be ground down a bit to fit on the guide pin. Also, 10mm shaft collar needs to be used, but will need to be slightly drilled out to fit over the shaft as it is 10mm in diameter and most collars are 3/8. It is only about
0.5 mm difference between the 2 styles of gear boxes when it comes to the shaft diameter. A set screw tightens into the channel at the front of the shaft. The original cotter pin is not used here. Click here for propellers.
12. After all aspects of the build are complete, the engine can be attached and throttle cabling run and adjusted as needed.
13. Now, remember when testing the operation, you need to be aware of the movement of the engine unit and the condition of the locks that hold the drive in place. All need to be in good shape and take it slow to adjust the setup.
14. Water should not be getting into the engine shaft or clutch housing, so pay attention to the height when cutting down the leg. You do not want it so low you are getting water spraying on the components above the deck constantly.
These 2 blade props are casted specifically for the use on these shafts. The rear hub will need to be ground down a bit so the pin connects to the rear of the hub. Because of the variances of different driveshafts lengths, the hub was made deeper. A stainless collar with allen head fitting willl secure it to the shaft. The collar will need to be drilled to 10mm if the diameter of the shaft is the wider version.
Although, this is essentially not needed to cut the system down, as the original can be utilized, some people prefer to have a custom stainless throttle system with billet components. All sizes can be created to make the throttle system more responsive and anti-corrosive to salt water.
These are brand new custom CNC designed at 45 cm or 17.75 inches to allow a few more inches of vertical adjustment. These are hardened driveshafts with 9T splines on both ends.
This is a 6 inch solid stainless steel rod that is utilized in the location of the ears on the Hobie block for the drive system. They fit right through the block and lock in to the factory locations.