The One That Almost Made It
We love a good resurrection story here at Valleyfair — and this 1995 Yamaha Kodiak 400 had all the makings of one. We picked it up from the original owner with a familiar tale: it had been run out of oil. It wasn't running when it arrived, and honestly, the prognosis wasn't great.
The Diagnosis
A seized cylinder. Compression was at zero — not low, not marginal, zero. For a lot of people, that's where the story ends. Not for us, that just increases the challenge and the reward
The Treatment
We soaked the seized cylinder in kerosene for a full 24 hours. It's an old trick, but it works — slowly coaxing the piston rings loose and breaking down the carbon and varnish that had everything locked up tight. After the soak, things were moving again.
Compression had climbed from zero to 50 psi. Better, but still not enough to run reliably. We splashed some quality oil around the cylinder walls and kept working it with the pluf removed. rolling it over and letting the ol dry engine get some lubrication.— and sure enough, compression crept up to 100 psi. We were in business. Note if you try this, roll the engine over with the pull start so you do not overheat the starter.
Will It Start?
Once we had compression it was tine for fuel and spark. We tested a new plug and had lots of fire....this always makes me happy as I hate chasing weak spark. Then we cleaned the carb, installed a new carb kit, fuel filter and new lines. So many times I have faught with an engine tht won't start only to have it be a bad fuel line. Save yourself the time, just clean all that sytem. Well guess what! It fired up and ran — and for a moment, it felt like a win. But then came the smoke and the clatter. A little smoke after a long sit isn't unusual; sometimes the rings just need some miles to seat back up. We ran a heat cycle and let her cool, then set the valve lash and changed the oil. At this point it was tine ti get the oil / Karosine mixture out, it will have cleaned everything. We kept running it for a few cycles, all the gears work, lights work, rear brakes and 4wd all good but no matter how much we were hoping the rings would free up they didn't. In fact, it got worse....much worse!!
Tear Down
We pulled the engine apart to find out why — and the answer was not pretty. The piston and cylinder were very badly scored, and the bottom ring and oil rings were completely seized to the piston. Maybe the cylinder could be bored out but honestly the parts are reasonably priced and we decided since the rest of the machine works very well that th eold bike was worth a new cylinder and piston. Running out of oil had done serious damage, but the old bike has lots of life left if we just give her a fresh start.
What's Next
We've ordered a brand new top-end kit — cylinder, piston, and a full gasket set. This Kodiak is getting a proper rebuild, and when it's done, it'll run better than it has in years.
Stay tuned. This story isn't over.