Don’t Ask: Dirt Bike Technical Questions Answered

Jun. 11, 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 … I’ll leave your e-mail unedited, for what it’s worth.

Previous Don’t Ask Columns
May 2012

April 2012

March 2012


You wrote a column some time ago and it's one of my favorites. It's all about loading bikes up and how dangerous it really is. I'd love to read that, once again.

You've asked, you got it. Here it is:

By Rick Sieman/July 1981
(Notes: Way too much of this story is true. Honest to God, I think I got hurt more – and more often – loading and unloading dirt bikes. Follow along and see what I mean.)

There are those who claim that flat track racing is the most dangerous thing you can do on a bike. Others say that going flat-out in Baja is treacherous. Some mention ice racing on spiked tires as a sure path to the Pearly Gates. Their detractors point out the controlled lunacy of road racing and the close-in violence of stadium moto¬cross.

Hah! The most dangerous thing you can do with any racing bike, without exception, is to load or unload the thing—from whatever conveyance you choose. I have personally lost more skin, bled more blood, moaned louder and squeezed out more tears attempt¬ing to load a bike, than I have in all the races I have ever ridden.

And that, as I am reminded constantly, goes back a long way.

The single most deadly thing you can load a bike into is a van. Consider: Once I was rolling a bike up a loading ramp into the back of a Ford Super Van. As the bike was heavy, it took a bit of speed to get it up the ramp. Just as the bike started its upward path, a gust of wind blew the left door partial¬ly shut. My knuckles caught the lead¬ing edge of the door and both the bike and I came to an immediate and painful halt.

However, the right side of the bike had a bit of momentum in it and swung lazily over. An instant later, I was on the ground with the bike on top of me, upside down. Gas dripped steadily over what used to be a good pair of pants. Naturally, I couldn't move and no one was around. So, I just laid there for a while, hoping the pain would go away. It didn't.

Another time: I had a bike on a trailer strapped in place with two tie-downs. After getting all of my riding gear together, I rocked the bike a bit to check it and made a last-minute deci¬sion to snug it down a bit more. For safety, you understand.

First, a tug on the right tie-down. Then, a good strong pull on the left one. Sprannnng! The ancient tie-down snapped and the bike absolutely lunged off the trailer and pounded me dead-center in the fore¬head. As luck would have it, the end of the bar made the initial contact—and the bar had a thrashed grip on the end. For about a month after that incident, I walked around with a big circle stamped in the middle of my forehead. Folks must have thought that I was a member of some odd religious cult.

More? You want to hear more? Okay. I had two bikes in the back of that same cursed Ford van one day and it appeared that the lever on one bike might kink the throttle cable on the other. It was impossible to move either bike, as they were both snubbed down in place. So I leaned over the bars and released one tie-down.

Now, if I had done this in the mid-seventies, there would have been no problem to speak of, because back then all of the bikes had maybe seven inches of travel. Tops. But this was one of those 12½-inch Maicos. When the pressure was taken off those massive forks, the bike rose up sharply and pinned my head to the roof of the van. The bars were rammed across my throat and I was being strangled by my own 490 Maico!

To save my life, I had to turn my head sideways and drag my head out from between the bars and the roof. I left a trail of blood against the roof that is there as of this writing, as a mute testimony to the perils of transporting race bikes. My ears looked like liver for about two weeks.

Enough? No? Alright. How about this? Once I was pushing a shiny, new test bike up into the bed of the vomit-colored Toyota DB truck. Things went just fine until I stepped on a number plate that was laying on the tailgate. Don't ask me how it got there. Please. Anyway, the number plate shot off into the air like a frisbee, and my leg spasmed above my head like a ballet dancer with a bad case of the Mexican trots.

A portrait is necessary at this point, if you will. Picture a full-grown, 200-pound man holding onto a motorcycle with both hands. One leg, as stated, is high above the head and straight as an arrow—toes pointed. The other is tucked underneath like a flamingo of sorts. The entire body is horizontal and about five feet from the ground. The loading ramp has taken a walk off to one side and is sus¬pended in the air. Only the front wheel of the bike is touching the tailgate. The bike is also leaned over, much like a road racer on the banking at Daytona. Freeze this picture into your mind for a moment. I refuse to relate what happened a fraction of a second later. Suffice to say that I walked with a pro¬nounced limp for some time after the accident.
No more, no more! Well, one more; but this is the last. After having had my share of grief with that vile Ford Super Van, I started using a great deal more caution when loading the bikes. I welded a bolt on the end of the loading ramp and drilled a matching hole in the floor at the back of the van so the ramp wouldn't slip anymore.

I had an extra section welded to the bottom of the ramp to guide the tires into the groove comfortably. No more slipping off this way. I bought a set of bungee cords to keep the doors of the van open and well out of the way while I was pushing the bikes up the ramp. I even went so far as to glue carpeting to the ramp itself, so the tires would grip, no matter what.
All bases covered, right?

It was a warm, spring day. I had to take a new bike out to the Dunes for a test session. The loading ramp was slipped into place. The doors of the van were carefully hooked back out of the way. All of the area at the back of the van was checked for dangerous debris.

Everything clear? Good. I clutched the bars and started pumping the legs. Bike and pusher picked up speed. The front wheel hit the ramp cleanly and the bike headed up the center of the ramp, straight and true. I kept two fingers poised over the front brake lever to slow the bike down when it was needed. That moment never arrived.

Somehow, some way, I had for¬gotten about the roof of the van. That cold, hard, unyielding roof caught me square in the forehead, putting a crease directly across the faint circular scar still there.

The bike had a great deal of momentum. So much so that, when my hands left the bars (involuntarily, I assure you), the bike hurtled all the way to the front and blasted a chunk out of the windshield and put the radio perma¬nently at 94.7 on the dial. FM, for¬tunately.

I refuse, absolutely refuse, to go into any more details. A man in my position deserves some respect! After all, danger is my business.


hey im 17 and 5'5 ish weigh 190 and am looking for a beginer bike i found a 225cc yamaha 2003 ttr for 2000 would his be good for me

It's Mr. Hey to you. The 225 or 230 would be the right height for you. The suspension on the TTR series of bikes is absolutely wretched. I did a project on the TTR230 and most of the time and money was spent on getting the suspension correct on the bike. I suggest that you read this series on our project TTR230 before you make your mind up on the bike.


I have a 1974 TM 250 I am looking to sell. How do I find it's value?
Brent Phillips

The bike in question is not a highly sought after collectors bike. The very next year, Suzuki came out with the RM 250, which was a truly great bike. It all depends on the condition of your 1974 model. If it's in excellent condition, it might be worth about $1500 to a collector.  If it's just in average condition and is running and is complete, it's really worth somewhere in the $700 range.


Hello. I find your advice both helpful and entertaining.

I recently purchased a "barn find" '76 KE175 for tame trail riding and short distance two lane commuting. It's in overall fairly good shape with 3000 miles, but it's been asleep a long time. I've put about fifty miles on it so far, it runs okay but not what I expected compared to my old RD250.

It starts fine, and idles a little rough but does not stall. It smells hot on rides over a few miles. It does not seem to have a whole lot of power (even for a 175) and seems to pick up power when I apply the choke while cruising. The biggest concern is accelerating off a light, I feel a "bang" that at first I thought was the transmission or clutch, but now believe to be a misfire (afterfire or backfire). Can you advise on where to start to isolate the issue? Thank you.
Vikki P

The best information you have given me on your 76 KE175 is that it seems run a little bit better when you put the choke on at cruising speed. This indicates that your bike is very lean at lower RPM. Now you may have cleaned the carburetor, but it's very possible you didn't take into consideration that the pilot jet has a constricted passage from the passage of fuel over the years. Yes, there is a buildup that happens over a long period of time from fuel flowing through various jets. Your best bet  (before you go changing the jet) is to clean it properly by soaking it in carb cleaner and running a small stiff bristle brush through the jet hole.  If the problem still persists, then go up one size bigger on the pilot jet and see if that solves the problem.


I have 1998 rm 80 that revs high. I have changed out seals on crank and checked all rubber at carb and idle. It was running good before I parked it.

Any time that any bike revs too high, check for some sort of air leak. It could be anything from a gasket on the reed cage to a simple thing like the carb cap not being tightened.


i have a kx 250 and one day after i got off the track i was cleaning it with my power washer and when i was taking it to my truck i shifted into second gear i hit the powerband and it was on the powerband for about 1/4 of a second and then it started to sputter and smoke came out of the pipe. i changed all the fluids and took of the carb blew all the jets and replaced the air filter and spark plug. it still wont hit the powerband, and on top of that my first race of the year is in 5 days.

Let's play detective a bit, shall we? Your bike ran okay until you hit it with the power washer, and then it ran but wouldn't take on the power band when you tried to rev out. Don't you think it would have something to do with the fact that you blasted the motor with high-pressure water? Chances are 10 to 1 in my book that you got some water in the carb.


my honda cr 80 1982 wont shift into 4th onwards 1,2,3 working perfect but once i try any higher gear it just goes into neutral? any help please?
stephen walters

Let's see now ... ‘82, ‘92, 2002, 2012. That makes your bike about 30 years old. Considering the fact that most minibike riders are truly wretched in the maintenance department, I would guess that your little bike is simply worn out. Probably the dogs on the top gears are badly rounded.


Hey Rick,
I'm looking into buying an 03' xr250r from my friend. It's in great shape and I love the bike, but I'm buying it primarily for driving to and from work because my truck's killing my bank account. As of now, it still has its off-road tires, but I'm thinking that I'd like to put on some sort of tire that would be better for everyday driving on the road. What i'd like to know is whether or not I have to stick with the 100/100-18 rear and 80/100-21 front tire sizes that are listed as it's stock specs. If not, what other sizes could I put on the bike?
Thanks for your time and help!
Jake Baker

Even though the XR is in great shape, why would you want to have an enduro bike for riding on the street? The XR is a pure dirt bike and would probably be illegal to ride on the street in stock form. You’d be much better off with an XL 250. However, you can find trials-type tires in both 18-inch and 21-inch size. These work just fine on the street and adequately off road. There are a few states where you can make any dirt bike street legal by adding a small mirror and some sort of lighting system.  So before you purchase the XR, check with your local Department of Motor Vehicles on the rules and regulations.


I just got a CRF 230F to ride with my kids and have the same concerns as most others on this website. If I was looking for a set of CR 250 forks which year model would be best to minimize my change over...
Thanks Phil...
Phil Hurta

Actually, we got our best performance with a set of CR 125 forks. You can use anything from a conventional set of telescopic forks from the mid-80s, to a modern set of upside-down forks. When you take into consideration that you can get a good used set of conventional telescopic CR 125 forks for minimal dollars, I would recommend that would be the way to go.


my 2001 suzuki rm 250 with new crank and piston ran smooth for about 4 hours of riding time then bogged down an wont crank
Richie Harper

Now what exactly am I supposed to understand from the limited information you gave me? Did the pistons stick? Does the engine spin over and doesn’t fire? Is there some sort of mechanical noise? How about a usable clue before I give you any sort of reasonable answer. Now go away.


Are the illiterate people writing in or is it rigged and done for comedy … i ride yz 80 over bored/re-thingyed and ports played with by the way your site rocks

Lest you think I'm just having fun with this column, all you have to do is read the e-mail above yours. That, unfortunately, is all too real. If I decided to include nothing but stupid e-mails each month in this column, there would be no room for rational letters.


But i got a 1980 suzuki rm80 2 stroke air cooled engine and i was wondering the fuel mixture i got the cheap walmart brand stuff i know its not good to because u have to run richer but whaht would u guys suggest???
Benjamin Murray

I always try to run a good premium brand two-stroke oil in any of my bikes. However, there've been times that I had to pick up some kind of generic two-stroke oil. At this point, I looked for the boating industry standards on the side or back of the can or bottle. As long as this is on the container, it's probably a reasonably decent oil.


i have a chance to buy a mx 100cc dirt bike but don't know where i would get parts for it or how good of bike do you think the mx is ??????
A few letters back, I was asked if I made up the truly dumb emails for cheap laughs. Again, sadly, I must confess that this is real.

Matt, if you want to get any kind of information, you have to give some basic facts about your potential bike. Like what year, what brand and so forth. Now go find the other dummy and stand in the corner with him.


on the the bick it has 393-008520 can u tell what it is or where to find info on this?  it was given to my grandson and he whats papa to fix it for him!!! any info will be a great help?????

Once more, into the breech. No clue as to what kind of bike or even a ballpark guess on what the year is. Get together with those other two dummies.


I have a dirt bike with vin # 462-004640. Could someone tell me make, year,model? Thanks Ron
Ron Johnson

Did you even try to look at the tag on the steering head of the bike and at least find out what brand it was? Nope? Is it too much to ask for that?


hi, I am relatively new to motocross, in fact I have only been on my friends 125cc ktm through some fields. I was wondering what a good starter bike would be good for me to start racing with and at the same time be competitive, I spoke to a mechanic who said I should be looking to spend £900 minimum for a racing dirt bike.

However I am not quite there yet because instead of sponging the cash off my dad I started selling my things and am now at about £600. I am looking at about £900 max and I am 13, I am also 5ft6 if that helps, thank you.

At your height, you might consider getting a bike in the vintage category. The conversion from 900 pounds is about US$1400, and at that price you could get a very good vintage bike. It would be easier to learn on. With a modern tall bike, you're going to spend a lot of time floundering about. 


where do i find factory specs for the jets setting on 1982 rm125

Pick up a manual to get that info. You can find them easily on eBay.


My motorbike is a yamaha DT250B form 1975. VIN: 450-223442
I need to find out the build date of the motorbike for rego purposes. Is there an official document I can get which gives me this information?

The most reliable method to get that date is to read it on the steering head tag. Take a picture of the tag, save it and print that out. Voila, you’ve got an actual copy.



Hi Rick,
considering im not using that 86 KX 500 for anything but fun?
Im gonna get a good 74 elsinore 250M,  and a 74 Maico 400 for long open area's, Ill put the elsie in local AHRMA event's. cant wait to ride a maico after all ive heard about thier frame geometry and linear power delivery. like the saying goes,,, your either riding a Maico, or chasing one!!!!!
Maico Nut

Excellent choices. The Elsinore is light and fun to ride, while the Maico is plenty fast and close to magic in the corners.


I have an 81 YAMAHA IT 250 basket case that I am putting together. I really don't care to restore it, I just want to get it running. What parts,or maybe what part DON'T interchange between the IT'S and the YZ 250&465's? I need a complete ignition ,will one off of a 465 work, or should I stay with the IT on ignitions. I want to keep that big flywheel. Also, I read the rear shock on an IT is about an inch shorter than the YZ, if this is the case, is it cheaper to buy a used YZ shock or to have the IT modified? Thank you oh GREAT ONE.
Daniel Sandberg

There’s a tremendous amount of interchangeability between the IT and YZ models. I would go with the YZ parts on suspension components and just use anything else to get it running.


I've got a that I've owned from new. It still looks new and runs fantastic. I took very good care of it, with the exception of it wasn't always off it's wheels all these years. The only mod I ever made was changing to Boyesen reeds and what a difference it made improving a broader powerband range. My problem is the monoshock. It just doesn't have the same rebound as when it was new. For example, when I apply weight it doesn't rise back very quickly into position. I've tried adjusting damping by turning clicker clockwise for firmer counter clockwise for softer but I really can't find any differences unless I;m missing something here?

My question is, can these be rebuilt and with what kind of success or should I just be looking a new performance shock and does one even exist and if so could you recommend? Perhaps these can be tuned up by changing it's oil and would that correct responsiveness ? Also, as you know their is a canister on the frame just under the tank which contains nitrogen canister likely still pressurized not sure what kind of precaution should be taken when handling. Any advise is greatly appreciated, thanks you sir !
Jim West

Your best bet is to get a rebuild from Works Performance.  Contact Gil at 818-701-1010 for info. Their shock mods really work.


hi i have purchased a yamaha f1se with vin number 3f6116308 i need to find a registration number for this bike
Michael Hill

Perhaps I’m the only guy in the world who doesn’t know what a Yamaha FLSE is. Please enlighten me.


Hello, i just got a "free" 97 suzuki DS125from my uncle im not sure on the story on it what i know now is i have spark but i don't you know the old hold this in your hand and touch the ground yepp shocked me but the only way i can actually get a spark is if i hold the center post on the plug to a ground and i mean hold it on i get just a little spark. not what i should i tried the new plug that is the right one gaped right rechecked wireing and and all looks good except the spark. any ideas this thing has sat out side and hasnt been ridden in at least 10 years... HELP please.
Tyler Jessen

If you can get spark sometimes then check out the spark plug cap and the plug wire itself. Somewhere, something is loose.  But not as loose as your writing style.  Full of second grade typos and no caps on the “i” are maddening.


Re: Kawasaki KX250
I have one of these for sale. Has been in storage for 20-25 years. Many unused parts. Wondering what I should ask for it?
Don Graves

Assuming that the bike is 15 years old, that would make it a 1987 model. Assuming that everything is in good shape and the bike starts and runs, probably about $700 to $800. 


I have a 1980 yz50 i need a exhaurst for and dont no what to look for can you help?
Seeing that the “exhaurst” is missing, you might consider looking for an exhaust pipe. They can be found right next to the “exhaurst” section.


I found an old Yamaha'72 JT-1 competition.I would like to restore it for my Granddaughter. It's pretty much complete but not in running condition. have any suggestions where to find vintage parts if needed. I have not yet had a chance to get into it yet,but was told that it ran a few months ago.
David Beard

You should no problem finding parts. I checked on eBay and found 1251 parts and manuals for the JT-1. You might also check out the following: The Vintage Japanese Motorcycle Owners Group Forums-viewtopic-Help


Hi Rick,
Regarding Sam Chesters KTM 300 that will not rev out, I had a similar problem with a 1999 model turned one of the copper wires coming out of the SEM ignition stator winding that connected to the ignition coil had broken inside the insulation. This wire, i think it was the blue one controlled high rpm spark.

Took some time to find as it looked perfect, changed plugs, and had the carby off a dozen times!

Hope this is able to help.
Dave Batten

Excellent tip, Dave. We’ll pass it on to our readers.


i still can't find this vin number anywhere it is a older yamaha dirtbike a 125cc with the vin of 1w1-002239

According to my Yamaha charts, your bike is a 1977 YZ-125D and the numbers started at 1W1-000101- 015610.


Hey, Rick!
I'm an old DB reader from about '68, and love your column. Just wanted you to know that my wife Betsy owns the largest used bike parts network in the country. It's called Just type used motorcycle parts into Google search and it's usually the #1 hit. It consists of about 100 used bike yards all over the country, and it's a great place for people to find a part for just about anything. Just thought you'd like to know, and maybe pass it along when appropriate. I envy your life and experiences, and hope that someday we can meet up!
Jeff Edwards

You got it.  We’ll pass this info to the ORC readers.


Re: 4-Stroke Maico
Reading the Don't ask questions and replies with a lot of amusement from time to time,

i just saw the pictures of the four stroke Maico.
Don't know who build it and don't even know wether it ran before it exploded.

But if you are interested in seeing an Maico that really performed, i'll give a link to the german rugginose forum... http://rugginose-deu/

It was build and ridden by Egbert Haas.
Makes for interesting reading, DT.


Hey i got a 1983 kdx 200 off this guy who blew the top end...and im just wondering i got it priced at about 310$ to fix but is it worth it good bike? no? just let me know please?

Nope, just part it out on eBay.


Re: '85 Yamaha YZ490
i have qustion about i keep fouling plugs im using ngk b8es plugs and red line oil 32 1 ratio
Kenny Nutt

Since the YZ490 is a leg breaking beast at best, consider fouled plugs a plus. If it doesn’t run, it can’t hurt you.



I found a vintage yamaha bike at my uncles house... just wondering if I could find some info on it. Didn't see the VIN on your list. 1M1-101257 is what i got off the frame. It's not all there and I was just curious about it.

The charts say that you have a 1978 DT250E.  They started their numbering system with 1M1-100101.


You may have seen this already, but on the chance that you didn't.  Have a question about the exhaust mod,  Project TTR230 Part 3.

You demonstrate how to remove the center baffle and drill out the spark arrestor as well.   Are you recommending that the center insert be removed, and in addition the spark arrestor be drilled out?   

Part 3,  where you went through rejetting the carb.   Couple things,  found it easier just to pull the airbox,  three bolts and hose clamp vs removing the intake manifold.  Pulled the snorkel,  and drilled the airbox,  and am awaiting delivery of the 38 pilot, and 130 MJ.  Believe the previous owner went up 1 tooth on CS sprocket, which may be fine for our app. 

I've got the plug out of the fuel screw and set it at 1TO, but how would you access that while installed,  the cam chain tensioner and crank vent hose make it nearly impossible to reach?   Might fool with the needle to see if it's adjustable others have used washers if it isn't.

Will be interested in any other mods or update you have,  not a bad little trailbike.
Ron Boals

All things considered, the Project TTR230 was a success.  We turned an ill-suspended trail bike into something fun to ride.  Sure, things are congested on the bike … getting to the carb is a real nightmare. But once you get it dialed in, you shouldn’t have to mess with the internals much.  Yes, we drilled out the exhaust completely, as it’s not required to have a spark arrestor here in Arizona.

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 … 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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