Don't Ask: Off-Road Dirt Bike Q&A (Dec. 2010)

Dec. 03, 2010 By Rick Sieman
Have a questions for Rick "Superhunky" Sieman, e-mail your Don't Ask questions to [email protected].

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 Don't Ask Columns:

November 2010

October 2010

September 2010

I have an opportunity to buy a 1980 Honda twincam 200cc. She says there is a small oil leak--also, that for that year it is suppose to leak to lubricate the chain?? Is that true? Also, what do you think is a fair price for this bike. Thanking you in advance for your attention.
D Esquer

It may come as a complete shock to you, but the name of the site is, not  The bike that you're asking questions about is a street bike, pure and simple. And as far as street bikes go, you couldn't ask for more dull and boring bike than the twin-cam 200 Honda. It weighs well over 300 pounds and has a pathetic 17 hp. It's so dull in fact, that the most interesting thing about the bike is in fact it does leak oil.


hey there, you wrecken it would be possible to Maori up a rm 125 top end to a 2000 rm 80 bottom end? just a random question? as im young buck looking for a challenge

Whatever gave you idea that you could put a ful- size barrel on a minibike crankcase defies logic. By the way, your spelling and abuse of the English language is interesting, to say the least.

My Name is Adam, I have Noticed you have a very sour taste about the yz490, thats a shame. From the track racing perspective, I would agree, But from the entertainment perspective I would disagree, I come from the stunt industry where pushing the limits and keeping people on the edge of their seats was my job, and for that the yz490 does it the best, Sometimes "Rick" the last bike standing wins, maybe if you have time you can check out my stunt bike "Venom" its easy to find google venom yz490, don't worry it wont hurt you.
Thanks sincerly
Adam T Dayen.

All things considered, the YZ 490 remains one of the worst bikes of all time. I had the unfortunate job of racing the test bike when it was brand-new, and in two 45-minute motos at Saddleback Park I tore off the calluses off both hands. The representative from Yamaha was there and he went through the jetting nightmare that is typical of the 490. In the cool morning, he had the bike running great. The minute the temperature went up 15°, the bike was almost un-ridable. Another 15° later in the morning and we had to re-jet again. By midday, the mechanic was into the jetting box once more. It was a heavy, poorly suspended, ill handling, vibrating SOB. The pros who did race the bikes had a complete re-machine of the top end and it bore no resemblance to the stock 490.


I have an '81 RM 465X. The gear shifter is stuck and I can't get it into gear. Any ideas what would cause this?
Mr. Taco


All things considered, the RM 465 is a good motorcycle with no real flaws, other than being a little bit heavy. Chances are the spring on the shifter pawl is either broken or has come loose, or the shifter pawl itself is damaged. Itís time to take the cover off and check things out.


i have a 1993 kdx 200 and im having trouble getting the rear fender off to replace it with a mx model thier is two bolts undernieth that just spin and spin and wont come out so i removed the seat and see they look like they go into a bar under their any ideas on the best way to get ahold of the nut or what ever is holding it together.

Since I have a 1990 KX 200, I know what you're talking about. The bolts go into little brass inserts that are molded into the plastic. Somebody probably over-tightened them once and caused the brass inserts to spin. Your best bet is to take a small drill bit and drill through the plastic and into the brass insets, then gently back off the bolt until it's free. I know this sounds like a weird way to get things done, but it actually does work. Good luck and while youíre at it, learn how to spell.

is the seat base on the 2006 crf450x the same as the 2006 crf450r, will they bolt up the same,

They have the same part number; thereforee, they must be the same. Go for it.


Hey my Kawasaki KX80's generator keeps seizing up. Can you help me figure out why?

Iím trying to figure out just what a generator is. Like many mini bike riders, you failed to give me any information that's helpful, such as the year of the bike and so forth. You have single handedly set the public's impression of mini-bike riders back a few decades. I hope you're happy with that. 


i recently purchased a yamaha 100 dirt bike the number i found on the right front fork is 427-000278 is there any chance i can get some information on this bike
Robert Lashley


The bike in question is a 1975 Yamaha MX100B. here's what I could find out about the bike:

ENGINE TYPE: Two-stroke single
LUBRICATION: Autolube and pre-mix
TRANSMISSION: 5-speed, left side shift
WHEELBASE: 50.8 inches
FRAME: Double loop cradle
FRONT SUSPENSION: Telescopic forks
REAR SUSPENSION: Swingarm w/Thermal flow shock
FRONT TIRE: 2.75x19
REAR TIRE: 3.00x18
CAPACITY: 1.59 gallons

Hello, I have a 1970 yamaha dirtbike and there is no gas going to the carb.. Any ideas on how to fix it? Also, do you know where to find a manual online?
Nicole Lamb

You're not really trying when it comes to finding a manual. A visit to eBay will find literally hundreds of manuals for your particular bike. As far as gas going to the carb, the first thing you want to do is take the fuel line off and see if gas is coming through the petcock. If it is, then you have to check the inlet of the carb, and this means checking the float needle itself. If the float needle does not release properly, then if it's stuck in the seat, you won't get gas flowing properly. At this point, you should remove the full bowl and see if gasoline does flow through as it should.


I am the original owner of a 1973 250 AJS Stormer that has been in rough storage for over 35 years. I want to bring it back and would like information on parts availability. If you could forward me any information I would appreciate it. By the way, you's looks great and has made me more determined to restore mine.
George McCraw

Parts for the AJ gas are very difficult to come by. Luckily, many years overlapped on parts usage. As I recall, the AJS was a great handling bike with a very dated engine and it had marginal competitive horsepower. Try Vintage Iron for parts.

dear rick,
I have a 2003 cr 85 that ran mint when i got it. But went riding one day and got into a crash and broke my wrist. The gas i was using was out of a bike my friend had recently bought (also a honda 2 stroke). when my wrist healed checked my bike and the other bike and they both had a stuck throttle. they will not turn and the bike will not start. i checked the kick start and it is not stuck and it still has compression. If you could help tell me what is wrong it would really help me out.

You're not even telling me what the real problem is. Is the piston stuck in the cylinder? Or is the throttle just stuck? Or is the kick starter not working through the stroke properly? If the cylinder and pistons are stuck on both bikes, it's possible that the gas on the other bike had no oil in it. Of course, if the bike has been sitting for a long time with the gas on, it's entirely possible that the gas may have simply leaked and drained into the lower end of the bike making it impossible to turn over. I'm going to need more information and proper information before I can even give you any kind of an answer.


I have a 1999 suzuki rm 125, if i have a 1 gallon gas container, what would the oil/gas mixture ratio be? Im not sure as to how much the ratio is on a rm 125.

For many years on my two strokes I've run a 32 to 1 oil gas ratio with great success. I can't remember ever sticking a top in because of poor lubrication. My oil of choice was YamahaR, although there are other quality oils available. Just about all of these two-stroke oil containers have a simple chart on the back telling what amount of oil goes to what amount of gas for what ratio is needed.
USA Mixtures
Ounces of Oil to Gallons of Gas
Gas to Oil 1 Gallon
Gas 2 Gallons
Gas 3 Gallons
Gas 4 Gallons
Gas 5 Gallons
16 to 1 8 Oz
Oil 16 Oz
Oil 24 Oz
Oil 32 Oz
Oil 40 Oz
20 to 1
BEST 6.4 Oz
Oil 12.8 Oz
Oil 19.2 Oz
Oil 25.6 Oz
Oil 32 Oz
32 to 1
OK 4 Oz
Oil 8 Oz
Oil 12 Oz
Oil 16 Oz
Oil 20 Oz

i have 2 bikes 2 problems wondering if anyone can help at all i an automotive technician so i know my way around engines but have somethings giving me problems i have a 1990 xr 200 had an oil leak from the person before me andhe fixed it with my help bikeran great it leaked again and he tried to do it himself after that he brings it to me and say it wont run he thinks maby timing cause it was a base gasket leak ad timing chain had to be removed well after a look it turns over ok until it would spin quicker then the lower rod bearing would sieze so i riped the crank out tried to do anything to help itgo around consistantly but freed it up a lil bit doint wanna spend the money to true the crank lol so i put it bak to gether and itl fire bout 4 times and stop then a kick or 2 is really tough(siezed) and then itll go around afew more times without crap idk any ideas popstarting kinda works fires maby 56 times before siezing worse thinking about 6th gear dragging it with a 4 wheeler? idk other bike is an 82yz 125 basically my powervalve wss broken off like the linkage but it was a crack in the aluminum valve itself so i tried and tried keeps breaking with every repair so i guess is theremaby a sweet spot to put it to get overall performance or does anyone have 1 i could buy there outragous priced anywhere i go... even ebay over 100 bux...
Jake Niss

Rarely have I ever seen such a disjointed e-mail. You are obviously trying to work with a lower end that is flat worn out, and through a series of rather comical efforts, you're trying to make it get better. It just doesn't work that way. Youíre going to have to get the crank rebuilt and that is the sad fact of the situation.

As far as your power valve problem goes, just replace the entire assembly and quit trying to do shade tree engineering on fixing the problem. It sounds like you're trying to fix every problem without spending any money, and unfortunately, it just doesn't work that way.
I just recently picked up a 1994 Suzuki RMX 250. I'm trying to get my father back on a bike. My friend has a 1987 DR 200. He seems to like everything about it except it's got one problem. Its got a high idle. It starts to go to its original idle for a second or two, but then proceeds to return to its previously high idle. My guess is the idle jet. My friend is a decent mechanic and put a new piston and rings in it. He has also tried replacing jets and cleaning the carburetor. Do you have an idea as to what the problem would be?

It definitely sounds like you have a small air leak in that DR 200. Where idle was a constant and now goes to a higher rpm that indicates an air leak. Check the top of the carb, the rubber boot going to the inlet manifold and very possibly a head gasket or a leaking base gasket as the cause of the air leak.


hey i have a 2005 crf230f and the back shock is really bouncy what could be the problem would the shock be busted??

First off, you have to consider the fact that the CRF 230 shock is simply and purely trash. I know, because I have a CRF 230, and tried to make the stock shock work. Springs and things of that nature failed. Eventually I gave up and went to a Works Performance shock and the difference was absolutely amazing. You really ought to read our series on project bikes on the CRF and consider doing the same to your bike.

I am a bit vertically challenged and looking for a seat that might be an 1/2" or more shorter. I love the bike (CRF450) but I feel like I am way up on top of the bike. Any suggestions are welcome

You could always cut the saddle down a bit, but there's not much to trim on the new generation saddles. Your best bet would be to go to a good local suspension shop and have them take about an inch out of each end of the bike. This will require different springs and adjustments.


hey im 13, 5`0 150 im sort of stocky but need somthing for a begginer and that will last me to a height of about 5`5, i was think maby in the range off, 100 to 175 am i correct in this thinking?

It 175

PE 175

Think about a Yamaha IT 175/200 or a Suzuki PE 175. Both of these bikes are fairly low and have excellent motors for learning riders. Shop around and you can get them cheaply.

SUBJECT:  Wide-Open Bog
i have a 2000 kx 125 and everytime i crack it wide open it bogs out. it also bogs out if i ease the throttle until its full pinned and as soon as it's time to hit power band it bogs out. i have cleaned the carb and need help or advice whether to jet it out or go down a size on the jet

If the bike is running clean before the problem started, chances are that one or more of the jets have varnished up to create that problem. It sounds like you've have dirt or water in your float bowl, but since you cleaned the float bowl, you can eliminate that possibility. Therefore, the only thing left is the jets. Clean them out and chances are your problem will vanish.


I was riding my 2008 CRF 100 today, like I have done, every Sunday with my family for the last year. Well, I had been going down a straightaway & I put on the brakes, made a turn. I came to a stop.Then I went to put it in 1st. The bike would not go into gear, I let off of the clutch & the bike kept running, like it was in neutral. I turned the bike off & my son went & got my husband. He tried to start it & it has no compression. You can push the kick starter, all the way down, very easily. Although when you push the kick start all the way down (at the very bottom of the push), the back tire moves in forward motion. It also will not go into any gears, other than what seems like neutral. No matter up or down, the bike always rolls like it is in neutral. My husband says he's never seen a bike do this. Any help or suggestions would be greatly appreciated. Thanks so much!
Kelly Bunn

Sounds like you ran it out of oil. They've been building that 100 motor since 1970, and it is pretty much indestructible. That's the only way you can kill one, other than running it over with an M1 tank.

First the shift drum seized up, then when they shut it off, a valve stayed partially open (seized in the guide). The rear wheel spins because of the friction between all the gears and the non-primary start shaft & gear.

Betcha if they check the oil there will be a tiny drop of crusty black stuff at the bottom of the dip stick.

Get the first four years of DIRT BIKE Magazine on discs. Those early copies are getting hard to find and the ones in the first year (1971) are going for big bucks. Hereís what you get:

*   Every issue from June of 1971 through all of 1974. That June í71 issue was the very first issue. I worked on all of these magazines until that last issue in 1974. Youíll see a big difference in content in that last issue and the ones that preceded it.

*  Every issue has every page included. All the color pages are reproduced in color. You can print out every page if you want to, since the issues were produced in Picasa 3 format.

*  Or you can put it in your computer (or CD/DVD player) and simply enjoy a slideshow of each and every year. There are seven discs included in the package. Each disc contains one-half of a year (six issues) in order. This comes to about 4400 pages total.

Hereís how to work the discs: Pop a disc in your computer and open it. An icon saying PICTURES will appear. Left click it.
Another icon will appear naming the disc (ex: DIRT BIKE 2nd HALF 1974). Left click it. This will bring up a bunch of dates/icons. Left click on the first one.

This will open up Picasa 3 and the first page of the magazine. Go to the bottom of the photo with your cursor and this will reveal the tool bar for Picasa 3. Itís self explanatory. You can make the page bigger or smaller, rotate the page, edit the page in Picasa, advance to the next page, make a slideshow out of the magazine by clicking the arrow in the middle, or simply print the page out by going to the down arrow (far right), click it and follow the directions.

The seven disc set costs $70 plus $5 for priority mail.  So get your very own piece of history.   go the STORE for  details. Newsletter
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