03 Wombat rebuild questions

[ncwLoren]

What are the opinions on oil injection . I have searched and it seems that some love it and some don't. I plan on having the hole drilled in the transfer port so that I can use pre mix but for some reason I think I would still like a functioning injection system. That being said I understand that oversize pistons for the 03 are very rare so a seizure could be really bad, Is it worth the risk ?

Thanks, Loren

[Al Harpster]

This is a touchy subject.

I've taken the Mikuni oil pump apart & examined it.

It's a precisely built mechanism & is remarkably simple.

I don't know what you mean about drilling a hole in the transfer port.

My thinking is you can put premix in the tank today if you choose. Perhaps others on this forum can comment on the drilling you mentioned.

Check with Hodaka Parts dot com Missouri about piston & ring sets for this model.

[Dale]

The 03 Wombat is the only Hodaka model that requires a hole to be drilled when the oil pump is removed. This is for lubrication of the left side crank bearing. The 03 Wombat has 2 oil lines with one designed to provide oil to this crank bearing. This has to be accounted for if the pump is removed.

Regarding the question about trusting the oil pump, I have no issue with using them. I think it depends on how you plan to use your Wombat. If you are going to be logging any road miles then the convenience of the oil injection is a plus. If it is going to be a trail bike or occasional rider, then I usually remove the pump when I do a rebuild. I have no science to defend this decision. It just make me feel a little better.

[viclioce]

I’m in the process of an 03 rebuild right now. The piston was free & both piston & rings were in good shape.

When I last checked with Terry Larson, he had both new 03 cylinders and 03 std pistons in stock. If I were to have a damaged 03 piston, I would likely have the cylinder coated with Nickaseal (Sp?) and rebored to fit a std piston.

The info Dale supplied about the oil pumps is correct. Either they work or they don’t. As long as it works they are safe to use.

The drilling required to go premix is in the left case above the left crank bearing. The rest of the Hodaka models have a pre-drilled hole in the left case above the left crank bearing which allows premix to lube the left crank bearing. The Model 03 does not.

If you drill for premix, you can go to a single cable throttle and purchase an oil pump removal kit from Terry. I did that with my Model 99 Road Toads. But they already have the hole needed above the left crank bearing.

It requires splitting the cases and securing the left case and drilling the needed hole to allow for premix to reach the bearing. I don’t have a drill press to handle this type of procedure, so I passed on it. Victor

[ncwLoren]

Thank you all. I guess what I'm thinking is to have the hole drilled for the bearing so that I can run pre mix while I make sure the pump is working. I have talked to Terry about this and he' thinks there is no wrong answer. Either way is fine. And he does not have any oversized 03 pistons, which kind of ups the stakes a bit. The left side case on my bike was pretty roached from a thrown chain but I just happened to notice that Terry has them on sale for $50 a pair so that problem has been solved.

Loren