Donít Ask: You Off-Road Dirt Bike Tech Questions Answered (Oct.)

Oct. 01, 2010 By Rick Sieman
If you choose to email a question to this column, 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.

I have a 1989 Kawasaki KDX 200 and was wondering if anyone would know what parts I could use from a 1985 KDX 200 on my bike. Thanks.
Needing exhaust
Robert Bexar

KDX 200

Here are the hard facts about the Kawasaki KDX 200. All parts from a 1989 to a 1994 are interchangeable. 1989 was the first year the KDX 200 was water-cooled. From 1983 to 1988, all the KDX 200 bikes were air cooled and virtually nothing is interchangeable. While the air cooled bikes were good, the Ď89 through Ď94 water-cooled bikes were definitely among the best bikes produced by Kawasaki.


SUBJECT: 2004 KX 60
sons bike new motor top and bottom was working good but now cilinder gets to much gas when u pull it over to check spark wont start
Danny Dury

The e-mail you sent to us is borderline babbling.  Just what in the plum-perfect hell do you mean by the cylinder getting too much gas?  I can understand pulling the bike over to get to the spark, because if you tried to check the spark while the bike was running, you'd be in a digital world of hurt. All I can make out from your missive is that possibly the bike is jetted way too rich. If youíd like to write back in some sort of rational manner, I'd be more than happy to answer your question.


i have recently purchased a 97 Kawasaki Bayou 220 it runs great lots of power but the engine has a loud tap to it. checked the timing chain seems to be in great shape. any info would be greatly appreciated

Since I have virtually nothing to do with four wheelers, this is most assuredly the wrong place to solicit an answer to what must be a straightforward question. Knowing nothing about the Bayou 220, it still sounds a great deal like something in the valve  train is out of adjustment or worn.

i have read ur article and im still a bit confused on what i should get. iahve no experince with dirt bikes. im willing to spend about 1000$. im a beginner. im going to be doing trail riding. im very athletic and sort of strong. im 5'5 and wiegh 160 pounds. im 14 so ya im growing at a steady
John Covacci

XR 200

All things considered, Iíd probably get something like an XR 200 for a starting bike. You could get a decent bike for something in the $400-$600 range. For $1000, you could get one of the nicest XRs imaginable. However, before you buy your first bike, try to ride it first. Assuming you can ride, that is. If you ride like you write, have a doctor nearby. 


When I shift my 2001 yz 125 out of first into all the other gears it sounds and feels like it is in the same gear.
Jacob Ponder

Maybe that's because it's still in the same gear. When you go to the next gear, does the bike increase in speed? If you go from first to second gear, you should be going faster. And if you go from second gear to third gear, the same thing should happen. It doesn't take a rocket science scientist to figure out if the gears are actually engaging the next higher one, or if you were sustaining in the lower gear. Use your head and not just your ears.


Yamaha Vintage ID Guide
1W2 is the prefix for the 1977 and 1978Yamaha IT175D and E.
David Riley

This information should help owners of Yamaha ITs a great deal. Thanks for keeping our readers up to date.


have 2 yamaha 100's vin #'s LS2-006087 and LS2-005280 would like to know year and model
Rory Straube

This is another street bike query.  Stop it!  The bike(s) youíre asking about are 1972 LS2 Yamahas.


hello i have just recieved a yamaha dirtbike and the numbers are LT2-
055899 AND I NEED THE SPECS thank you

Yamaha LT2 and LT3 specs are pretty much the same. I threw them in here for your edification. From the serial number you supplied, I assume your bike is a 1972 model. The 1973 versions start with number 105101.


Overall length 75.2" (1,910mm) Ignition type Point-type magneto
Overall width 35.4" (900mm) Ignition timing 1.8mm
Overall height 41.3" (1,050mm) Spark plug type/gap NGK B8HS/.020-.023"
Wheel base 48.8" (1,240mm)  (.5-.6mm)
Road clearance 8.6" (220mm)  
Battery 6N4A-4D (4 amp-hour)
Fuse IDA
Headlight 6V, 25W/25W
Maximum output 10 bhp @ 7,500 rpm Tail/brake lamp 6V, 5.3W/6V, 17W
Maximum torque 7.0 ft.-lb. @ 7,000 rpm Turn signal lamp 6V, 17W
Maximum speed 58 mph Neutral indicator lamp 6V, 3W
Fuel consumption 152 mpg © 31 mph Speedometer lamp 6V, 3W
High beam indicator lamp 6V, 1.5W
Type 7- port reed valve  
Displacement 5.92 cu. in. (97cc) TRANSMISSION SYSTEM 
Bore x stroke 2.047 x 1.795"  
 (52 x 45.6mm) Primary reduction ratio 74/19 (3.895)
Compression ratio 6.9:1 Transmission/overall ratios 
  1st gear 35/11 (43.4)
  2nd gear 30/15 (31.8)
FUEL SYSTEM  3rd gear 26/19 (18.6)
Carburetor  4th gear 23/23 (13.6)
Manufacturer, model Mikuni VM20SH 5th gear 20/25 (10.9)
Main jet 130 (LT3=120) 6th gear N/A
Needle jet N-6 Secondary reduction ratio 49/14 (3.590)
Jet needle/clip position 4J13-2 (LT3=4JB-3)  
Cutaway 1.5 >  *
Pilot jet 25  
Air screw (no. of turns out) P/4   (LT3 = l1/2) STEERING 
Float level 21mm Caster 61°


I purchased an older yamaha with a number of 583-005265. Any idea what it might be!
Thank you

Your particular bike is a 1976 TT500C.


i have got a rolling frame tank etc of a 1977yz 250d model serial number 1w3-000250 what is it worth as it is and how much done up and how can i find out who owned it before and do you no any one who is interested in it and where can i get parts for it engine etc

If you have just a rolling frame without the motor, electrics, pipes, etc., then the very most you could get would be a few hundred bucks. Parts for Yamaha's are all over the place. Start with eBay and look for a complete motor there, but of you can't get it cheap, the bike is probably not worth fixing up for resale. You could end up putting much more money in an old warhorse than if you bought a complete motorcycle ready to go.


have a blue RD200 with the coffin tank, matching frame and engine # 1J1-000151. I would really love to know which sub-model it is.
Paull Chunn

I realize that this may come as a shock to you, but the name of this site is, not We don't do street bikes here.


im looking for rings for a yamaha yz 360 1974 any suggestions

Just about any part for vintage Yamahas can be found at the following place:

Toll Free Tel: 866- 455-6831 - Tel: 570-784-6831 - Fax: 570-784-6835
Address: 305 Montour Blvd., Bloomsburg, PA 17815
Mon, Tue, Wed, Thur, Fri 10am - 6pm, Sat 9am - 3pm
Eastern Daylight Time (GMT -4)


have a vintage yz 80 I think. Water-cooled. engine # 5x2-005181 Please tellme what I have and where I can find a repair manual.
Bro Dave

You have a 1982 YZ 80J.  You're not even trying. A simple trip to eBay will find a bunch of manuals for your particular mini bike.


Hi Rick:
I would please like to know the correct sag setting for the rear Fox Factory Dual shocks that I have on my 1980 Honda XR500. The riders who remember riding these old bikes are getting fewer in numbers but my XR500 is still being trail ridden. Nice simple bike with weak brakes.
Bruce Bodenhofer

Unlike single-shock bikes, dual-shock bikes never really had a sag setting that was recommended from the factory. However, I found that 50 mm of sag works okay for most riders. Try that and let me know.


i just got a 2003 klx 110 it was working perfectly fine until it started idling real hard like you were reving it and then u put it in first and it would move by itself. So i was trying to ride it back to my house then it just cut off when i went to kickstart it didnt really catch. It just goes down and makes a weird noise do u think i just need a new gear or is it something wrong with the engine. thanks for the hellp

You didn't include the name of your city and state in your e-mail. This is probably because there is a university in your area that specializes in Babbling Incoherently and you must have graduated with flying honors. Rarely have I ever received a communication like this. There is so little real information here that all I can do is shake my head from side to side, much like a confused water buffalo. Now go away.


Hi, I have a 1 year old 09 crf450r. All the fluids are good, the spark plug is good, pretty sure valves are good, and I haven't touched anything. When and only when the engine is hot (about an hour or two of riding on the track), it starts to bog. Should I just bring it in. I haven't brought it in since I got it. The bike gets about 2 hours on the track every 1-2 weeks

If you have about 20 hours on your Honda CRF 450, you're probably ready for a complete engine rebuild. This might come as a shock to you, but this is the reality of the new four-stroke racers that the manufacturers are trying to foist off on the public. For example, in the Honda CRF 250 manual, it states that after 15 hours of operation at the hands of an expert, you're ready for a rebuild. 30 hours is about the maximum you can go riding if you're not an expert. What will a typical rebuild cost you? Figure on about $3,100 bucks and that doesn't count the transmission or the clutch. So you can see if you ride your bike every weekend, you're looking at five or six rebuilds per year. This makes a whole lot of sense? No, but that's what they're trying to ram down our throats. It's really makes you yearn for the simpler days of the reliable, easy to work on, low-cost two strokes.


hi there was trying to track down a piston kit for a ZEE DEE mammoth 90cc? any help would be great thanks.
aaron shuttleworth


What you have here is another one of the Chinese rip-off bikes.  However, the only good thing about this one is that it has a 90cc Honda engine as the powerplant.
Since this bike is intended for a kid, the copy that came with the ad brochure is a bit odd. Check this out:
"This dirt bike is ideal for leisure use and can give a lot of freedom on the mountain or beach. This bike has a lot of tractor pulling torque. We were quite surprised the first time on the Mammoth. It flat out hauls butt! We tested it with the trusty GPS unit and it was blowing past 50 MPH with a 225 pound test rider. The exhaust note is something else. It's not a strangled cat sound. More like a deep rumbling throb that a good 4 stroke performance bike should sound like. This is not a putt putt 10MPH bike for 6 year olds. You could almost get on the freeway with it and keep up with traffic. You will be amazed with it. This is one of, if not the most popular kids (and grown up kids) dirt bikes we sell. Throw a couple on the back of the RV and you will have a blast. This is an awesome brand new in the crate 2004 ZEEDEE Mammoth 90cc with a reliable 90cc 4 stroke Honda authorized engine. Comes with kick starter, CDI ignition, 4 speed semiautomatic transmission, front and rear drum brakes, tool kit, instruction manual, full 3 month parts warranty."
Dimension (l x w x h): 63 x 26 x 35 (inches)
Wheel base: 41"
Seat height: 24"
Min. Ground clearance: 6"
Dry weight: 144lb
Transmission: semiautomatic 4 speed
Lubrication: Auto
Starter: Kick
Ignition: Cdi
Max. Speed: 35mph (factory says 35, in testing we have topped 50)
Fuel consumption: 120+ mpg
Front tires size: 250 x 14
Rear tires size: 300 x 12
Brake f/r: drum/drum
Hand/foot: hand-f, foot-r
Engine: 4-stroke Honda clone
Engine cooling: Air
Displacement: 86cc
Lights front/rear: None
Racks: None
Msrp: $1,595

When I ramp a hill my Yamaha TT-R 125 stalls and i think it is flooding the carburetor? How do I fix this?

Chances are very high that you have some crud or water in your float bowl and every time your bike gets at a weird angle, the debris momentarily clogs the main jet and stalls the bike. Take your carburetor apart and clean it and that should do the trick.


Hey Rick
A friend of mine bought a tore down kx60, 2000 model and the woodruff key keeps fallig out of the crankshaft, he spent about 1400 on all parts including transmission, crank , basically all new internal part, now I somehow got sucked into this thing, and he had not had the nut torqued down We have determined that it is working its way out from behind the pinion gear, ever heard of this scenario? I tightened up with an impact, still waiting on the end result, but the way he had it put together, it was not that loose, we have a manual for up to 2002 kx 60, but it really doesnt go into much detail on this. Any advice would be much appreciated. Thank you in advance.

What do you have is a worn-out seat for the woodruff key. If it's worn and sloppy, there's no way that the woodruff key is going to stay put in position no matter how much you tighten it down. You're looking at new parts at this point.


i have a 1984 yamaha yz80 dirt bike and it has no spark if you could help me i whould apperciate it if you could help me get spark back in it and let me ride thank you
Cody Burk

With the rather limited information that gave me, it's virtually impossible to troubleshoot your bike. Why don't you start out with the basic stuff first? Remove the spark plug and put a new one in place, then see if you have spark. That would be the first step. If you've got a nice fat blue spark at this point, you could forget about anything else and you're ready to go riding again. Failing that, you should check all of your connections on the entire wiring system for corrosion, rust, or water. Anything in the system like this could cause a complete lack of spark. Take it from there.


i have a 1999 yz 125 and the kick start gets stuck when the bolts are tightined but when really lose it doesnt get stuck why is that thanks
Tyler Edawrds

It sounds like you have the kick starter positioned too close to the engine side cover and when you tighten it down, the kick starter is rubbing on the cover. Take a screwdriver tip and leave a little bit of space between the cover and the kick starter when you tighten everything down and it should work okay.


The right side of my 1977 Hodaka 250 SL gets covered with black oil after even a short ride. Yes, I know it's old, but I have a fondness for old two strokes.

My exhaust pipe has the inner pipe in place, but no spark arrestor/silencer. I
have thought the oil injection may be rich, but with the amount of oil I'm
seeing, I would expect to be fouling plugs, and I'm not. I think the previous
owner may of rebuilt the top end using a Suzuki piston and rings. Is this
kosher? Is it possible that crankcase oil is sucking into the exhaust pipe when the piston is at the top of it's stroke? Is there a difference in piston skirt
length with a Suzuki piston? I can't ride the bike like this, oil was running
down the rear shock and started pooling in the rear wheel and dripping off the license tag. Any ideas? Anyone
know a good Hoddie mechanic in Florida?

You probably have a sloppy fit with the exhaust pipe. Check out this and the problem should go away. It is very possible that you are sucking trans oil through the engine because of a bad seal.


re: 1985 Honda XR 350
Does anyone know ify there is an electric starter kit you can add to this bike?

I know of a few starter kits that are available for the XR 400, but am not aware of any made for the 350s. You might consider adding a compression release to the XR 350 for easier starting.


i have a 1990 ktm mx 250 and am trying to find what years/what bikes have the same forks i've called the local dealer and they have been less than helpful both front forks a shot due to accident and would like to find a suitable replacement for the bike to rebuild from

All you have to really do is measure the forks and any fork that will fit into the triple clamps would be a direct replacement. If you go to a much newer fork than is currently on the bike, you might also have to replace the front wheel if the axle sizes are different.


Hi there just wondering if you could help ive just resently brought a yz 250 2001 old i know but just getting back into it as had a few years off.The problem is i cant seem to bleed the front break i took the master cylinder cap off cracked the bleed nipple till i was geting a steady flow of fluid comeing out to flush all the old fluid out i let about 4 master cylinders full of fluid run through the system then done the nippel up pumped the leaver and nothing so pumped the leaver hold it in crack the nipple do it up again release the lever i reapeated this procedure over and over so any clues as to what the probblem could be would be a great help thanks for your time
Ross Smith

Do you realize that you have not only butchered the English language with this e-mail, but you have spindled, mutilated, raped and pillaged it as well. Normally, I would give a rational answer to a rational question and bleeding the brakes falls into that category. However, your rampant abuse of the written word almost defies description. For that reason alone, I will not answer your question, and instead I will print your e-mail out and do terrible things to it.


I'm rebuilding a 1986 CR500, and had a question about springs and sag. The original (I guess they're original) springs are sacked and the bike sags a lot. I ran Race Tech's spring calculator for my weight (230lbs) and it recommended a .45 and 5.6 spring set. They no longer offer a 5.6, so I ordered the next closest spring which is a 5.0 (which is stock). For Hare Scrambles/GNCC type riding, do you think this will be sufficient? Does the .46/5.0 combo sound like a bad idea?

Also, I have a set of 1986 and 1988 CR500 fork springs, and was wondering if I couldn't run the .46 in one leg, and the .38 in another (if warranted)?

And last, how much sag do you recommend? I've been finding various answers to this, and would like a little input if you would.'

Thanks sir!

1986 CR500

The best, all things considered, would be to use fresh stock springs front and rear. At the rear, you can compensate for your weight by the amount of preload and sag in the shock. 100 mm of sag would be about right on the rear.  Up front, start with fresh stock springs, but you may have to raise the fork oil level a bit to compensate for your body weight. Try this first.


I have a 1975 honda mt250 elisnore i'm having some trouble with the turnsignals they light but won't flash. the winker relay has 2 connections on it with wires connected to it but a third wire [green]which i believe to be the ground isn't connected to anything can you please tell where on the bike it would connect to.
thank you
Richard Cook

A ground wire can hooked any metal surface that eventually hooks up to the frame. That would be the handlebars, swingarm, etc.


i have been restoring a 98 suzuki ds80 and i rebuilt the top end completly thought that was the problem and after i did that it was reving out high on its own to, but not sticking, that was the seals and gaskets in the bottom end, if i gave it the slightest bit of throtle it would revout really high, after all new seals, gaskets, bearings, piston rings, she runs like a top,

There's no question about it; you have an air leak somewhere. When the throttle is not sticking and the engine revs way too high, that's a dead giveaway for a serious air leak.


I just got a 1994 KX 80 from a buddy of mine. this bike has been sitting for about six years and just needed the top end rebuilt. So I rebuilt the top end, cleaned carb, jetts, fuel tank, air filter, and rplaced fuel lines and spark plug. I can"t get it to start? Compression sounds good, got a spark, fuel appears to be getting to carb. Help!

KX 80

Whenever you have all the necessities for a bike to run properly in place, it must fire up. You have fresh mechanical parts, clean carburetor, proper jets gas flow, clean filter, and a spark plug that works. The only thing you haven't covered here is the timing. If your timing is off, all those things are meaningless.


Speed Shifting/Power shifting (No Clutch)

What are your thoughts on doing this/ I am 47 years old. Race 79 and 88 YZ 250's. Will this do damage to my tranny?

Any suggestions on better suspension for the 79? The 88 runs and handles pretty good as is,

Since youíre doing vintage racing, you have to remember that you are riding older equipment and that getting parts for this equipment is becoming harder and harder. In the old days, I used to just take my Maico and just clicked through the gears and not use the clutch. Now I race a 1983 Maico and I take a little time and use the clutch each and every time I shift. I don't want to go through the expense and hassle of trying to find new gears for my 490.  Just a bit of advice.

Trials riders run mixures as high as 125 to 1 with no apparent ill effects. Do air-cooled 2-strokes have different oil mix requirements from water cooled engines due to greater clearances? I remember Preston Petty (of fender fame), one of the US's best early MX riders around 1970, advocating 10:1. His Maico smoked like the devil as he beat all comers! It's a very mirky science!
Jack Atkins

Preston was an advocate of very high oil-to-gas ratios, and on the bikes of that time it seemed to work fairly well. However, for my entire riding life, I have used a 32 to 1 mix ratio quite successfully. And for most of that time I used Yamalube R two-stroke oil.


I have a 1990 suzuki dr350. I dont know much about bike engines but what had happened is I blew a gasket on the kit start side of the crank case. I did the gasket myself, put it all together the way i thought it went but now when i try to shift i the shifter does not spring back. The bike still shifts but now when i shift (say I'm shifting out of 2nd) i have to step down on the shifter before i can shift up to 3rd
Ian Berry

1990 SUZUKI DR 350

It sounds a great deal like you have parts rubbing on each other because of incorrect mounting, or improperly tightened parts in the shifting linkage. Also check out the spring on the shifting pawl.


Great article: Loved ever line, and y 1981 Maico 490 is very hard to start too, I bought it new and still have a very hard time getting it to kick over. I am always the last to get on the trail embarassing to say the least. Some times it takes me 45 min and 75 kicks to get it to start up. I have plenty of spark and gas...I even prime it directly into the spark plug hole at times.
Any advice?
thanks Russ

1981 490 MAICO

One of the tricks riders used to do was to lean the bike over until gas poured out of the carb. Then the bike would start on first or second kick. Or just simply do what I just did my 490 Maico: I put a 38 mm Mikuni carburetor on the bike and it starts right up.


I just bought a KTM 520 and it makes a knocking noise but when I pull in my clutch it goes away. Do I need a new clutch or what might cause that? Any help would be appreciated!

It sounds like a bearing on the clutch basket is going south. Iíd check that first.



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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