New Project Bike, SMC YB150

[kens]

A new brass crush washer will solve the problem if there's no strange issue with the valve cover casting. No worries about taking the screw out and it should be a very simple fix. Hight-temp RTV would be a good and cheap solution since you shouldn't need to mess with that screw much, if at all.

Unless you add an external oil cooler that is. Hmmm...

CC

Whats your thoughts on aux oil coolers on 200 -250cc bike carl ?

[CrazyCarl]

Well I'm not an oil cooler expert but I do know cooler oil is better than boiling oil!

There's a lot of things involved in adding an oil cooler. The frame has to be ready to accept a cooler..as to the clearances like tank, plastics, wheel and header.

Then you'd have to be sure the oil pump can handle the extra volume. Someone PLEASE correct me if I'm wrong but a higher volume of oil and passages would create a lower systemic pressure.

You could always tap in somewhere with an oil pressure indicator and make sure the oil pressure doesn't change much. At the same time, you could run an oil temp gauge to find out how much cooler your engine is running.

For racing I think this would all be extremely valuable info but the cost/complexity may not be worth it (probably some added weight as well). Some additional input from more experienced members in this field would be really helpful.

CC

[barnone]

ACDNate,
You have an interesting build going on. I remember you from ADVrider where you reported on your purchase of this bike.
BTW, in case you don't know, another site that might help you is http://planetminis.com/ .
Good luck and I will follow your build here.
Another BTW, I ordered the BMW GS mini clone that was mentioned on your ADVrider thread to bust some BMW chops. I'll report on it here on this site once I get it.

[ACDNate]

Adding an oil cooler wouldn't be a huge undertaking really. I've added oil coolers on older bikes using oil filter adapters that gave an outlet and inlet. As long as you add additional oil to fill the increased volume of the cooler itself, pressure wouldn't be an issue. There would be a slight loss of pressure but typically less than 1-2 psi tops.

In a small displacement engine I can't imagine you would really need one unless you were doing some kind of endurance racing. It wouldn't hurt but probably wouldn't be necessary.

Thanks, Kens I wasn't familiar with those abriviations.

Barnone, you're gonna have the BMW loyalist in a tirade when you post pics of that thing! :)

[ACDNate]

Also of interest I got a call this morning at 830am from the dealer. All the repairs are done and the bike is ready to pick up. I was rather shocked since I just dropped it off Weds. Not too many dealers will get a job done that fast. Going to pick it up tomorrow am and will be putting the bike in the dirt sunday :)

[ACDNate]

So I went and picked up the bike yesterday. Took it out this morning for some fun in the dirt. Boy it's been a long long time since I've been in the dirt. It rained a good bit yesterday so the dirt was soft and tricky. Somehow I managed not to kill myself. Did get me and the bike pretty muddy along the way. Didn't take any pics but my buddy did do some video with his Iphone. Video montage to follow

Everything worked as expected for the most part. The carb will need some work though. The bike did not want to catch an idle off of choke. Ran and idled fine at the first notch of choke. I'm thinking I need to bump the jetting up a bit. Any input?

[CrazyCarl]

If its a problem at idle, changing jets might not do much for you depending on the type of carb you have. What does the carb look like?

You can always try to back out the Air/Fuel mixture screw a bit. It may be set real lean at assembly.... that's been known to happen. Also, did you adjust your idle speed?

Fork seals okay so far?

CC

[ACDNate]

The carb is a knock off of a Keihin Round slide carb common on dirt bikes.


I'm much more familiar with Mikuni CV carbs. So to richen the idle mixture screw backs out, same as CV's?

Forks did well, with no signs of any weaping. Definitely need to get the heavier forks for a guy my size. Had a buddy who weighs in around 170lbs and he found the forks to be pretty well setup for his weight. He too commented on the rear shock being too soft.

[CrazyCarl]

Oh yeah, I've had a bunch of those carbs. In China I found a carb which basically dropped right in to my Honda clone 150 and it kicked ass. Wish I could remember the number. It had a slightly larger diameter slide tube and an accelerator pump. More power on both low and top end... especially top end. Not sure if I have any pics of it either. Hmmmm...

Anyway, yes, with those carbs screwing them out will richen the circut...they're quite simple designs. Might want to check current position against seated first and all that jazz.

CC

[ACDNate]

I've got to pull it out and get some bore measurements, but I believe I'll be going to a Keihin in short order, just don't have a lot of faith in knock off carbs.