Vintage Dirt Bike Q & A

Does anyone have any idea why water or condensation would form inside the Left side cover? I had the side cover off 3 days ago to replace the points. I sealed it back up with a greased fresh gasket and the rubber seal for the primary wire was intact. Everything was dry when I took it apart, and the only thing I added was a light coat of axle grease to the gasket, and a light coat of cam lube to the cam. I also put one drop of 30W oil on the oiler felt on the cam, because it looked very dry. The temp was about 80F degrees when I buttoned it up, with a dew point of 56F, so it wasn't extremely humid. After replacing the points and setting the timing to 2.3mm BTDC, The bike ran fine at mid range and WOT, but was very sluggish on picking up RPMs from idle. I pulled the side cover off yesterday to double check the point gap and timing, and found almost 2 cc's of clear water in the side cover. I had washed the bike after riding it and letting it cool down, but used only a light mist to rinse this area, so I doubt that this is where the water came from.

Could this be condensation forming inside this cover, or, since after washing the bike, I let is rest on the side stand and any water not wiped up that was on the engine casings allowed gravity to let it run down to the Left side cover and somehow infiltrate the new gasket? I'm hoping that it was the latter, but with all of the knowlege and experience on this board, I am hoping that this isn't indicative of some more serious problem that someone may be familiar with.

One other note. When I first started putting this bike together, there had been some clear water in the crank area inside the casing halves. I never split the casings, but while the jug was off, dried all this out. The crank seals seem to be OK (no excessive smoke, or problems idling or running that would indicate a problem), although I've never pressure tested them, and the casing halves seem to be sealed. I don't know where the clear water there came from originally, but I assumed condensation from sitting for years was the blame at the time I found it. I had just put fresh Castrol 10W40 in the gear case when the points were replaced, and the bike was only run for about an hour and a half. The trans oil had been replaced about 2 months before that, so I don't think that contaminated old oil caused a problem. However, when I went to pull the plug on the Right side cover, to check the oil level, I found that I must have overfilled it slightly while it was up on a center support, and was slightly overfilled when setting level on both wheels. Anyway, the 30 cc's or so of 2 day old oil that came out was somewhat gray and discolored. If this bike was liquid cooled instead of air cooled, I'd suspect a cooling system problem, but I am a little stumped as to where this water is coming from.

I'm hoping this isn't something nefarious. Any ideas?

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Steve Amling

1976 CR 250M
1980 Yamaha DT100G
1980 XR 200
1981 CSR650

My bet it's water from washing the bike. A simple test would be to dry it out and ride the bike again without washing it to se if water or vapor forms. But more than likely it was from washing the bike. For what it is worth I always pull the side covers on all my bikes after washing them to let the flywheel and stator dryout. You do not want to have rust forming in here. This only takes a a couple of minutes but can save you money in the long run. Terry

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Terry Moody #48f
3x 74 Honda CR250M Elsinore
74 Honda XR75
73 Honda QA50
78 Yamaha YZ125E
78 Yamaha YZ250E
78 Yamaha YZ400E
79 Kawasaki KX250
79 Honda CR250R
79 Suzuki RM400
80 Honda CR125
2x 83 Honda CR480R
98 Kawasaki KX250

Thanks for the feedback Terry. Hopefully, it was only water from washing it. I have to pull the cover again any way to play with the timing again, so I'll check it. After putting in the new points, and timing it as per the manual, first, the power band seemed to be from mid to full throttle. I retarded it abit, and now it seems to hit the power band at lower throttle, and bogs a bit at full throttle. I've never had this kind of trouble getting this timed right before.

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Steve Amling

1976 CR 250M
1980 Yamaha DT100G
1980 XR 200
1981 CSR650

Hi Steve

I noticed you have the manual for that bike. Any chance you would like to sell me a copy?

Rowdy
mailto:plwright@bigpond.net.au

As long as I have a particular bike, I have to have a manual for it. The manual I have for this bike is a Clymer
http://www.clymer.com/Book.aspx?bid=496&title=Honda+125-200cc+Elsinores%2c+1973-1980

But, the Clymer manual usually isn't my first choice. For the Elsinore it is a little confusing by including MR's, MT's, CR's, 125's, 175's and 250M's and 250R's all together. You have to make sure you are following instructions for a 250M, because if you aren't careful, and take your eyes off the manual for a second, you can easily find yourself looking at instructions for a MR or MT, or a 250R, or even a 125 Elsinore.

I normally prefer the Haynes' format, pictures, etc... to the Clymer, and they are a little more specific to a bike, than Clymer's shotgun approach. Not to mention, they are usually a little cheaper.
http://www.themotorbookstore.com/hon250el.html

There are used Chilton's manuals for the 250M that pop up on e-Bay from time to time and they are good too. I never used the one for the Elsinore, but have had them for other bikes over the years. When I first got the CR250M, I had a Honda shop manual for it, but have no idea where it went over the years that it sat before I got around to actually working on it.

Good luck on your restoration. But, definitely get a manual of one sort or another, before you get too far into it.

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Steve Amling

1976 CR 250M
1980 Yamaha DT100G
1980 XR 200
1981 CSR650