Custom/Hybrid Melmack's very unique 300sx build

[Melmack]

Here's a pic of the intake grate. Its a kawi 650sx grate. Believe it or not, it fits perfectly with no modification at all. It turns out the 650 pump cavity is about 2 inches longer than the 300sx. When I tried this out, I was shocked to see how easily it bolted up. Not only that, it fits into the Yamaha shoe perfectly. The bolt holes are perfectly lined up. I don't have a pick of this right now but it is installed and ready to run. All I did was mount the FX-1 shoe and bolt this intake up. This should help with the FX-1 hookup issues.

 

[Liquid Graffix]

Is this gonna be a problem since it isn't flush with the hull? Are you going to add glass or silicone it?

 

[Melmack]

This was before I actually secured it to the hull. It still sticks out just a bit but it's now flush to the hull. If I feel this effects the handling, I could modify it a little. I had this same issue with my FX-1 mod. It didn't seem to cause any issues there. The shoe is firmly attached to the hull, the protrusion is in a low pressure area past the intake so hopefully, there will be no issue there. Keep in mind that I could have and still may make this flush with a raised lip around the intake. This is found on several AM hulls. For now, I have cut the pump shoe out to fit the cavity not the other way around. I wanted to avoid major glass work if possible for this prototype.

Good eye BTW. Keep the ideas coming. I relish the criticism and observations.

 

[Melmack]

On a side note, the paint on the inside was absolutely mint until my best Jackarse friend decided to thin the split oil with paint thinner. Thanks buddy :icon16:

 

[bobob729]

looks great....cant wait to see at lsfr....maybe ride very clean and still coming along let us see how it runs this weekend

 

[swapmeet]

Very cool build, I think I saw that 300 on CL did I not?
Can't wait to check it out at LSFR!

 

[Melmack]

Yea, someone here told me it was in Houston's CL.

 

[Melmack]

Fired her up today. She sounds good. Had an issue wit the prop but fixed it no problem. Revs very quick with the new pipe and carb. Just need to glass the top of the rails and re-turf. Hope to put her on the water tomorrow for a quick test before we ride Sunday.

 

[Liquid Graffix]

Pics of the motor and pipe??

 

[Melmack]

Here you go

 

[WFO Speedracer]

I see your problem now, someone done stole one of yo cylinders;

 

[Liquid Graffix]

I see your problem now, someone done stole one of yo cylinders;

LOL ^^^^^^^

There was a thread somewhere where a guy was asking about more power for his 300 and someone suggested adding a cylinder to make it a 650 and the guy believed him.

 

[Melmack]

Hold that thought. That's exactly what I'm up to.

 

[Melmack]

Running into an issue. Never, in 15+ years had this happen to me. My prop keeps spinning off when out of water and I kill the engine. I have changed hundreds of props and never had this problem. The shaft doesn't wobble and the prob was just balanced by Impros. I cranked it back on yesterday as tight as I have ever tightened a prop. Came out this morning, ran the ski for 15 seconds and as soon as I let of the throttle, it came off again. Anybody have any Ideas?

 

[Liquid Graffix]

Nomes! ...Sneaky little b@s-turds. Lock your tool box at night!

 

[Liquid Graffix]

Is the shaft worn down at all? Are the threads good or worn? Could be that you tighten it down and it seems good but if the threads are off a bit and it doesn't fully catch then the high RPMs would surely knock it loose...

Just a thought... I'm interested to see what the deal is.

 

[Melmack]

Well, the threads are all in good shape. I was reading a thread on this. Someone suggested grease on the threads would make it seem tight but then come off when the ski reved down. I do remember the treads being greasy. I wiped them off but never actually cleaned them because I was saving my tiny bit of carb cleaner for the carb job. I tightened the spank out of it yesterday so I was surprised when it came off again. Before I go to the water this afternoon, I'm going to try to get to the treads and clean them off a bit. I want to try to tune this thing and see if the pitch is correct before pulling this thing apart again. I'll post up with my results later today.

 

[Pablo]

Use thread sealant. permatex.

 

[chad]

did you have it in reverse?

 

[Melmack]

Yep. That was it. I had the reverse bucket down. LOl.

No really, I went ahead and pulled it apart. Thurns out there was a ton of grease everywhere. I think that contributed. I cleaned it off and did a big no no and put blue lock tight on it. Hopefully it will hold but not too well.

I'm in the process of turfing so it doesn't look like I'll be riding until tomorrow afternoon. Stay tuned!