86 CR 250 with a ton of problems

Well I bought the bike, it was a great deal. It started up first kick every time. Only problem was there was water mixing with the oil.

Well I decided to take the jug off and take a look. Turns out when they rebuilt the top end they reused the gaskets so I figure that could be one reason oil and water is mixing. Another is the hairline crack in the cylinder sleeve. The bottom end feels good there is no play in the crank.

Could it still be a bad waterpump seal making water and oil mix still? Or was it most likely the crack in the jug? The cylinder head looked pretty rough too.

What should I do? I can't find any machine shops to re sleeve it other than online. And it looks like it would be just 100 bucks more to do a big bore kit with it. Should I send it off and pay 3-500 dollars or just junk it out?

Also the powerbands weren't opening all the way up when I was riding it around. No idea what would cause that because I put a brand new reed cage in it and cleaned the carb. It's jet is size 60.

So what should I do? Are there any machine shops that wouldn't charge and arm and a leg to re sleeve it? Should I junk it? Or just save up again and buy a newer 2 stroke?

Remember, a 2-strokes crankcase is seperate from the transmisson. There is no oil in the crankcase but there is oil in the transmission so when you say water in the oil you can only be referring to water in the transmission oil. To continue, the crankcase is seperate and sealed from the transmission so things that would put water in the crankcase like cracked liners and bad head gaskets will not put water in the "oil".

Now I will be helpful. Water cooled Honda bikes generally have a tell-tale under the water pump cover. There are actually 2 seals on the water pump shaft with a small void space between them. There is a hole drilled from the outside to this void space. If the water pump seal fails, it will leak water through this space and you will see a drip from under the water pump cover. If you're getting water in the oil without a water pump seal failure, it's because you have pinholes (caused by corrosion) in the side cover. That vintage of Honda happened to use a magnesium side cover which was very prone to corrosion. The pin holes can be repaired by bead blasting and epoxying.

You'll have to get the bike resleeved to repair the crack, this should cost around $200 including the price of the sleeve and then you will have to buy a new piston. The water pump repair will cost a bead blasting and some epoxy.

The "powerbands" or more commonly called power valves are not opening is because they are either carbon fould or set up improperly. You have to pull the right side cover, pull the cylinder, set the power valves up in the open position, install the cylinder, install the right side cover, adjust valves until the close fully with the engine off, and ride. These years were notorious for sticking valves due to carbon deposits. After changing to good quality synthetic oils I haven't had to clean the power valves in the last 3 pistons.

Don't think this is going to be a low maintenance bike because it is an old bike. If you ride it hard it will require just as much maintenance if not more than a new bike. My 87 burned up it's last piston in 2 months which was 25 hours of riding. I am constantly going through chains and clutch parts. The rear suspension linkage requires constant maintenance. The forks require frequent oil changes because the springs rub on the sliders and put shavings in the oil which plug up the valving.

Don't think this is going to be a low maintenance bike because it is an old bike. If you ride it hard it will require just as much maintenance if not more than a new bike.

Thats just what I was going to say.

Yeah, but they are damn cool bikes to have!

I ride the piss out of my 87, the last piston lasted 2 months and I'm due for a new crank. I go through fork oil ever 4 rides or so, shock oil makes it about 4 months. Chains and sprockets depend on the season. The linkage and swingarm bearings require constant attention. The clutch is another major issue. They're damn cool to have because they make great mid-range which supprises everybody on the track when you pull them on the corner exit on a conventional fork bike. They'll get you at the end of the straight, though.

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