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June 1999

BF Knows!

From: LCL651
Subject: how fast ..?

Hi , several years ago I had a very successful hare scrambles, cross country racing I'm older an own a 1993 XR 600 (which I'm starting to like) its barley street legal and I would like to know just how fast I can run this thing on the road...?.70 mph just doesn't seem to get....!....I want more....can I have it...?...or am I dreaming....?


BF Knows:

Given normal aerodynamic drag, and an acceleration of one G, terminal velocity is around 240 mph. Naturally, you better have your compression damping turned way up for the G-out landing.

Don’t tell anyone, but I was tooling along a while back at around 95 mph on Skyline Drive on my ’86 XL600. Getting up to speed with proper overall gearing was no problem. It was getting the dang thing stopped with the whimpy front disk brake that was a problem. Also, if you gear up for higher top speed, first gear will not be low enough if you are like me and get suckered into riding on cliff-hanging ledges and over very large rocks.

From: LISK4
Subject: KLX300

Dear Conehead,

I'm extremely amused by your writing and almost roll out of my chair with laughter. Thanks for your efforts and time.

I am also considering purchasing the KLX300 but hear it has a problem slipping out of gear in high torque conditions. I also heard Kawasaki was working on it but can't find anyone with more info. Are you aware of the past problem and do you have any problem with your 98 KLX slipping out of gear?

Would greatly appreciate your response.


BF Knows:

My bike only slipped out of top gear once. I thought, "Oh $%#*. I got one of those @*&# gearboxes." It had around 700 miles at the time.

I had read about the possible gearbox problems, but also read that Kawasaki fixed it after the first year run of the KLX300. The bike now has well over double the mileage, and has never slipped out except that once. Draw your own conclusion.

The bike is my favorite all time dirt bike for the kind of riding I do. It is light, handles well, and is confidence-inspiring. And when you ride like I do, you need all the confidence you can get. Just be ready to pay for a pumper carb, header, and exhaust diffuser. The power delivery in stock form sucks.

Subject: Baja trip

I read your Baja ride report and it sounds like you guys had a lot of fun. Four of us here in Georgia are trying to put together a trip to Baja for the end of October. I read that you hired a guide named Richard. Could you give me his contact info or any other guides. Any other info or tips would be great.

I would greatly appreciate it

BF Knows:

Richard is our own personal find. Get your own.

Brad and I met Richard at the bar at Mike’s Sky Ranch four or five years ago. Actually, we were drinking and talking to some of his buddies when Richard rode in well after dark. Another guy had gotten a flat and Richard stopped to help fix it. We hooked up with Richard two years later.

If you can’t or don’t want to explore Baja on your own, you can get info on professional tours from Baja Designs 619-578-9111. Their Web site has a links page for Baja off-road tours at

Avoid the dirt road to Puertocitos. It is a bear. The paved road isn’t much better. Puertocitos is a hole, anyway. The ride from Tecate to Mike’s Sky Ranch, via Laguna Hanson, is the best. There are several rides around Mike’s Sky Ranch that are very challenging and very fun. It is all high country, so you may hit snow or rain in the early Spring or late Fall. San Filipe is a fun ride and a fun town to visit. Spring Break is the best time to go there. Lots of scenery, if you know what I mean. It is too hot in the Summer, though.

Pack light and bring dinero. Do not count on being able to use your credit or ATM cards anywhere except in the large cities. You’ll have to use cash for most purchases. US dollars can be used anywhere. You can barter in most shops, but not for gas or in restaurants. Pack most of your heavy stuff on your bike, not on your body.

Learn a little Spanish, be friendly, and show some respect. That will be returned in spades.

From: GS
Subject: Please help

I am currently in the process of buying a 98 CR250, however it's been sometime since l had a bike and there was a few questions l needed answering:

1) When l had my bike back in the early 80's you had to mix the oil with the Gas, is this still the case with new bikes. If so what is the best mix for a 250cr and what's the best oil on the market (I use to use rock oil back then).

2) Is there an organization I can join for motocross in the USA so you can register to race?

3) How often do the new bikes need an oil change?

Thanks for your help and this probably won't be the last of my questions.

BF Knows:

  1. Yes. 45:1. Red Line Two Stroke Racing Oil.
  2. Yes, your AMA local district.
  3. Read the manual. Jeez.

From: Phatkdx
Subject: XR100

My brother has a brand new XR 100. Sometimes, like the typical air-cooled 4 stroke, it is hard for him to start when its hot. I was wondering if I could change the jetting (i.e. richen) to make it easier to start when warm and to improve engine response. I have heard that Honda likes to run things lean for emissions.

Just Curious


BF Knows:

All non-competition EPA-era bikes are jetted lean. We mustn’t pollute.

Having said that, increase the pilot jet one or two sizes. Raising the needle one clip position probably wouldn’t hurt, either. If it blubbers or runs rough after those changes, put the carb back in its stock form and live with it. (Right Jay?)

Subject: hi

I would like to have a 4-wheeler please send me back saying yes or no.

BF Knows:

Yes, by all means, have a 4-wheeler. Let me know how it goes.


Why are the rear suspensions on bikes like the DT175 and the AG200 different than your standard dirtbikes? Is the performance of the different suspension any different?


BF Knows:

What are you talking about? The DT175 is a standard dirtbike. It uses the standard Yamaha mono-shock configuration prevalent in the late 1970’s. The AG200 is pretty much the same.

Today’s "standard" dirt bikes typically have their rear shock mounted in a near-vertical orientation in which a rising-rate linkage at the base of the swingarm is used. A rising-rate suspension linkage allows a bike to track better in fast harsh off-road conditions.

The rising-rate linkage is also more complex than the old-style Yamaha mono-shock. Maintenance is higher for the rising-rate because there are more bearings to grease. (Right, Paul?)

The triangulated swingarm on the mono-shock is also cheaper to build. To get the same stiffness on swingarms without the extra tubes requires the manufacturer to use large cross-section aluminum with tapered sections. Current dirt bike swingarms are much lighter than the old-style mono-shock swingarms, but they are also more expensive.

Given that the DT and AG are sold as dual-sport beginner bikes, I can understand why Yamaha went with the cheaper mono-shock configuration. Another riding buddy of ours has a 1979 Yamaha YZ490. He is never slow, and does not appear to be hindered by the mono-shock suspension. (He is sometimes hindered by his enthusiasm, though. That’s why we call him Loopy.)


BF Knows! - Bryce F. (Conehead)
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