Donít Ask: Rick Sieman Answers Your Dirt Bike Questions

Jul. 05, 2012 By Rick Sieman
If you choose to email a question to this forum, then you must conduct yourself accordingly. Therefore, the following rules are in order:

1. Do not write your email to me IN CAPS. If you do so, I will print out your question and do terrible things to it.

2. Do not request a personal e-mail response. Since I get thousands of questions each month, trying to answer them all would cut deeply into my leisure time, which I value more than your current state of confusion.

3. Try to spell at least in a semi-correct fashion. If you choose to mangle the English language, expect no mercy from this quarter. You might be mocked severely.

4. Do not ask for me to send you copies of my many manuals and literature. I am not in the library business, nor do I want to spend the bulk of my day at the copy machine just because you're too lazy to ask your dealer,  or look around a bit.

5. Don't bother me with truly stupid questions, like how to get 50 more horsepower for a buck and a half

6. Now that you know the rules, think carefully and have at it!

Oh yes Ö Iíll leave your e-mail unedited, for what itís worth.

Previous Donít Ask Columns
June 2012

May 2012

April 2012

I bought this earlier this spring - minus an owner's manual. What weight oil should I be using and how much when I change the oil? Thanks.

Jerry R. Williams
Lafayette, CO

The manual calls for 0.9 liters of 10W-40 weight oil. However, if your little 90 has a lot of miles on it, I wouldnít hesitate to use 20W-50 in the warmer months. Just a personal thing I would do. If your 90 is perfect, then stick with the recommended oil.  


Mr. Sieman,
I have a 1985 Kawasaki Kl 600. It works great, former owner did a good job building it. I would really like a street legal two stroke. What would be your thoughts on a Kx500 engine swap into said kl? 


I have never been a fan of the KX 500. It was a vibrating fool and then the vibration put your hands to sleep after an hour or so of riding, even at trail speeds. It took a mighty kick to get it lit and sometimes it would bark back and almost take your foot off. The KL 600 had an electric starter commencing with 1985. A street bike should be easy to start, easy to ride and pleasant to ride. The KX 500 motor fits none of these bills.


Hey Mr. flunky
Just where do you get off telling people that there bikes aren't so good, huh?  I mean just because your real old doesn't mean that your all that smart.  I'm only 17 and I'm smart.  I am smarter than you about bikes.  I've owned seven bikes since I've been 12 years old so I think I know what I'm talking about. Why donít you just retire?

Billy the kid Martin
LA, California

So you've owned seven bikes? Why, that's amazing! Thatís just about how many I have in my garage right now. During my more than 50 years of riding motorcycles, I have owned hundreds of different bikes. In the process of ownership, I have learned a few things enabling me to pass some of this knowledge on to other riders. However, since you know it all, my suggestion is that you go away and don't come back until you manage to grow up. Thank you and goodbye.


Hi Rick,

First of all thanks for all the good work cover the years. I purchased first Dirt Bike magazine (the one with the ďhow to slideĒ article) back in the early 70ís and thought it was the best thing Iíd ever read. You guys were the first to say it as it was, not as the manufacturers would have you say it. My bike at that time was a Norton 99 and after reading your magazine, I immediately headed to the fire trails (well power transmission line tracks actually) and thrashed the poor bike until its valve guides fell out. Since then itís been a sporadic succession of on and off road bikes Ė but have settled on a mix of KTM 4 stroke and KDX 2 stroke bikes to feed the off road bug.

My question concerns the fork supports which are fitted during transport between the front tyre top  and the lower triple clamp underside. They are claimed to save the fork seals, but I cant see how. In fact I cant see any real usefulness for them other than making it easier to tie down as the forks donít get compressed so much. Do they really serve a useful purpose or are they just more fad junk?

Thanks , best regards and please donít stop writing.
Steve McKenzie (East Taieri, New Zealand)

Actually, these supports keep the motorcycles from moving around while being transported. With the rigid piece between the front tire and the triple clamps, the forks cannot go up or down as a transporter hits bumps, or takes corners. I agree with you that saving the fork seals is nebulous, at best. But for people who transport bikes for a living, these things do actually work.


Hey Rick ...
I figured you would a good guy to ask ...
I have heard of a Publication on the Torsten Hallman HL500 `s ....
Have you ever heard of this Book ?
Do you know the Name of the publication 7 or the Author ?
Any Help would be greatly appreciated !
Mark Allan Palermo.

Mark, I did a ton of research on this and no such book exists. There are, however, some records of what Hallman did to the stock motor to make it live. Here are some comments by a man called Big Sven:

ďNice looking bike, but the only real good thing about it are the Ohlins shocks. If that's a standard engine it WILL break. The rocker arms snapped like glass and there was something seriously wrong with the lubrication system and the gearbox shafts bent under full throttle, causing teeth to strip from the cogs.

ďThe fit of the various engine-parts wasn't good, you needed to strip the engine and check and mod it as best could before ever taking it out on the track, cylinders were often found to be leaning over, not square to the cases, for example, and the conrods could be bent (as well as being 2-3mm too long for effective power-transfer). Racing engines they were not.
Hallman drew-up blueprints for a dedicated racing engine, knowing the Americans liked big 4-strokes, but Yamaha vetoed it. The famed 3-valve head was a spin-off from this, he made various bits to show the Japs. The 3-valver gave a slightly better throttle-response and acceleration, but Hallman's test-rider told me if it was his money he'd stick to the 2-valver. Hallman had designed his new engine with the cylinder leaning BACKWARDS, to improve the inlet angle for best performance, but to fit the head to the standard engine he had to bend the inlet to fit the carb into the frame, thus the inlet didn't flow as well as his original design. But. I'd dearly like to see Hallman's 4-stroke engine design! I'm sure THAT was a right cracker!Ē

As you can see, Hallman knew what to do to make the engine live and perform well. There is no book on the bike. The knowledge and the secrets are in Hallmanís mind.


I don't know where you get off bad mouthing three wheelers. I bought a Honda 250 wheeler a year ago and it has been very reliable. In fact it is much faster than my buddies dirtbike. I go out to the dunes all the time and just eat those new dirt bikes a live. So how do you explain that? As far as I'm concerned you can just kiss my *** and you can go to **** you big ***** you.
No name given

Dear Mr. no-name, it might come as a shock to you, but the only all-terrain vehicle that was ever voluntarily removed from production was the three-wheeler. There were so many lawsuits against the manufacturers of three-wheelers, they couldn't justify producing them anymore. The three-wheelers invented a new type of injury called the three-wheel break. In that, the rider catches a leg under a rear wheel and breaks it severely. When the wheel rolls off the broken limb, the two broken pieces snap back together and create terrible damage to the tendons and ligaments. Often it took many operations to repair the damage.  Operations meant lawsuits. Take it from there, bozo.


I have a atc125m I have recently redone the topend becuase it wwas smoking and spitting out oil it starts and idle fine all day bit wont go in or out of gear its like the shifter is stuck and when you go to give it has it just bogs down like its jammed up. any iideas would be great thanks.

So you have an ATC 125. That's well and truly fine, but I think it would have entered your mind to tell what brand and year it is? Actually, the only thing jammed is your thinking process.


I have acquired a yamaha enduro 2 cycle motorcycle serial # JT1-205342 would like to get a manual if possible? and would like to know where to get parts?

There are several sites on the Internet that specialize in mini cycles and three that concentrate on the JT1. Just do a Google search on it. As far as getting a manual, eBay more than likely will get you one.


Hello Rick.
While surfing the web for Hodaka related information, as I was not sure how these engines arrived in Portugal, I found this page. As I have some photos of a Forvel with a Hodaka 125 engine and a road test published in a portuguese motorcycle magazine of the time ANFESA was building the RT125, also with Hodaka engine, I wonder if You would like to have some photos of the Forvel and a copy of the ANFESA RT125 test.

Regards from Portugal

Paul Stannard, the owner of Strictly Hodaka, made the trip to Portugal and found a bunch of bikes. They were originally going to be sold in Portugal but that never happened. Paul was able to buy a number of these units and you can reach him at Tell him Rick said hello.


We bought a 97 blaster with a motor from a 2000 Blaster on board. The previous owner rebuild the motor and had a bored over 2mm it has a 40 mil carb. The bike keaps fowling plugs. We are using the stock ngk plug. Also the oil is blocked and we are running 40/1 mix. Any suggestions
Lenny Hutchins

It just sounds like a simple matter of leaning out the jetting. Start with the main jet and keep going down one size at the time. Each time you do a main jet replacement, put in a fresh plug or clean the existing plug out with contact cleaner so you can get a good reading on it. A good reading in this case would be chocolate brown. Once you get to that point, youíre home.


The idiot looking for an exhaurst pipe just needs to go to his nearest "deler". Jeff Edwards says he's been reading Dirt Bike Magazine since 1968. Tell him I will give him $750 for each Dirt Bike Magazine up to the 6/71 issue. I don't care if htey are dog eared and ragged. I'll buy them all.
Hell, I'll pay more than $750 for each dirt bike Magazine. Why? Because the magazine didn't come into production until June of 1971. I have to know since I was the editor of that magazine.


My name is Jeremy Keleher. I live in Guelph, Ontario, Canada. I just purchased a bike a month and a half ago, i got to ride it six times and the bottom end blew. Would love to replace it with a new motor. Could you help me locate one. Thanks.

Jeremy Keleher

Oh, so you'd like to replace the mystery motor in your mystery   bike, would you? You don't think it would help a little tiny bit if we found out what make year and model you had, do you? Nope. I thought not. Not go away until you grow some brain cells.


I had a Gemini Boss 80cc dirt bike when I was 11 years old (1971). I want to find another and rebuild similar to what I had. The engine was not yamaha it was a San Tong and most everything else is a JT1 Yamaha. I managed to purchase the owners manual yesterday which should provide good info during the rebuild. Do you have any knowlwdge on this bike that I can start my research project with.

The Boss Gemini 80 - and many other small bikes - were powered by a Phoenix F480 or F500 engine, also known as the Fuji 80 and 100. They were used in the Alsport Steen, Bonanza, Chapparal, Condor, Barnt, Cycle Trend, Bandit Trail and MX, Foray Sno-cycle, Fox, HPE/ElGato, J.C. Penny Tigre, Rupp, Toyoda and, of course, the Gemini.

The company was located in Vancouver and for all we know, they still might be in business. For what it's worth, the address was/is: Gemini Ind., Ltd., 2525 Stephens St., Vancouver, B.C. Canada.

The compact two-stroke engine came in a four-speed and five-speed version and was sold by Pabatco in Athena, Oregon, as the U.S. distributor. These are the same folks who sold the legendary Hodakas.

Hi I was just wondering if you have ever heard of a mini bike called an Eastern Star. Made in Taiwan in late 60s early 70s.

Sue Kirwan

Howís this? An actual photo of the bike.


Have a 1984 YZ125,,,looking for a good aftermarket pipe,,can't find anything that goes back to 84 for this bike,,any ideas? Thanks.

Again, I must reiterate that I have been able to find parts for almost any older bike by going to eBay. I'm not joking about this. Heck, I was actually able to buy a piston and a connecting rod for a 250 Greeves quite easily.


In the TTR project, one thing I've found it that the stock chain guard/guide is a joke, it may keep out wayward sticks and weeds, but really doesn't act as a guide similary to the ones on the WRs. I was able to find one at have it on order, but it appears so be what I have been looking for. They also have them for the CRF230.

Ron Boals

Thanks for the feedback on the TT 230. It turned out to be a very good project. We never had any trouble with our chain guide, but there aren't very many sticks and weeds in the Arizona desert.


i have a 1992 honda xr250r that me and my father rebuilt after we got it for free from a friend who crashed head on with a quad on it. it was mangled and we brought it back to life. i have blown it up and bored it to a 280. and now that i have grown i still need more power. it has 13/48 gearing i am about to go to 13/45 in hopes of going faster, but i can tell it needs to breath. i have opened the airbox up as much as i am comfortable with and now im looking at exhaust and jets. i have searched all day for slip-ons that will fit it and havent found any. it has a "e.a.r. soundtrapp" on it. what are some slip-ons that will fit it, and what jets should i run with them?
brett whitaker

All you have to do is check that exhaust tip has the same OD as the ID on your new muffler. The XR250 is not a highly stressed machine, and most any exhaust muffler between 12 and 18 inches long will do the job. As long as it fits on the pipe, chances are it will work okay. As far as jetting goes, it's virtually impossible to tell you what to do depending on the kind of muffler you get. 


hi i am a 16 year old and have had this (vintage to my knowledge) yamaha 650cc dirt/road bike in my basement and because i was unsure about the wireing i have not run it but i am curious what does the engine need to run? (kickstart)
Noah Matthews
Considering the fact that Yamaha did not make a 650 dirt bike at all, chances are you have a street bike stored in your basement. Get down on your hands and knees and take a look at the steering head on the bike. Right there, you'll find a little plate or tag of some sort that will show the year and model of the bike. With that kind of information I give you a rational answer. Without it, you cannot ask a rational question.


My new book, THE LAST RIDE, is at now out. It's fiction and starts in 1969, when an 18-year-old kid just out of high school gets a chance to ride his Yamaha 250 DT1 from Pennsylvania to Los Angeles Ö all off-road.  His adventures are truly amazing. The book then jumps 40+ years where the same person, now in his 60s, wants to get that old Yamaha back in his possession and return it home by riding it all off-road across the country again.  The book is $15 plus $2.75 for mail anywhere in the US (or $5 for Priority Rush mail) and for more information, the email is: Newsletter
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