Don't Ask: Rick Sieman Answers Your Dirt Bike Questions

Sep. 03, 2013 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.

Have a question for Rick ďSuper HunkyĒ Sieman? E-mail questions to [email protected], Attn: Donít Ask.

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my 2001 honda 125r has a motor knock its not real loud but idling you hear it when reving cant hear it is this normal
It sounds like you have the connecting rod starting to wear out. When a rod bearing is a little bit on the loose side, you can hear it knock slightly at idle or very low revs. However, when you raise the RPM, the bearing stays in contact with the crankshaft more and you canít hear the knock. Unfortunately, it seems like itís time for you to take that motor apart and fix it right up. After all, itís more than a dozen years old.
hey you  just where in a hell do you get off talking to people the way you do, I mean just because a guy rights you an email that isnít quite perfect you rag all over him, who gives you the right to do that huh? I mean where do you get off really.
LA California
This column receives a substantial amount of mail, and unfortunately a certain percentage of it is nearly indecipherable. The emails that are sent by people who can barely read are worth nothing more than ridicule and yours just about falls into that category. Now go away and donít come back.
I want to drill out my 125 main jet to 130 equivalent, what drill size should I use?
greg black
Before you go drilling out the jets in your carb, consider the following: not all carb makers use the same measuring system for their jets. Your safest bet, if this is the route you want to go, is to put a drill bit in the 125 main jet that just fits perfectly. Then, locate a 130 main jet and carefully insert another drill bit in there until you get one that just fits. Then, you can go back and drill out your main jet. One word of caution: make sure that you scribe the new size on the jet in some fashion, so that in the future you or the next bike owner knows what heís dealing with.
I am in the process of restoring a 1978 Yamaha yz400 with my foster son. We are 85% complete but there are three items we are unable to locate thus far. With your reputation and years of experience I thought it wouldn't hurt to try. You just might be able to help us complete our project.
The items we are looking for are 1. Stock or performance exhaust pipe 2. Air bock w boot and brackets & 3. a kickstand. I know this email is a bit random but I my foster kid and I know we are on the final stretch and the bike should be done shortly. If you are unable to help us but can point me in the direction of someone who may, I would greatly appreciate it. Thank you for your time and have a wonderful evening.

Thank you,
#Eddie Quiñones#

Apparently, you havenít tried eBay. I went there and typed in 1978 YZ 400 and got 2813 hits. Virtually anything and everything was there and the prices were all over the place.
Hey Rick,#

Got a 1998 RM250 that smokes like a freight topend,no difference.then i replaced the crankshaft seals thinking i was taking tranny fluid,no difference. Exhaust is freshly repacked and mechanically the bike is very sound. smoke and congestive running are the symptoms i'm having. It will not idle or come on the pipe at all.#    

I have been using my service manual to the "t" at this point & am getting discouraged. Oh wise one,i was told about you by my buddy Tommy....he say's that you know the answer & i should ask you. He also told me to read the funny answers you give. Funny stuff Rick#.
#Ryan Colinger
#Lynchburg, VA
Possibilities include a clogged-up exhaust port, mis-adjusted oil pump for the crank lubrication, worn-out gasket between the transmission and the crankcase, pipe is clogged up with muck and it smokes from all that muck. You didn't give any performance information, good or bad. Itís possible that something is wrong with the carb. Lastly, Iíd really need to know what kind of oil you run and what ratio you run it at. For starters, I would run a good mineral oil at 32 to 1. Then put a fresh plug in the bike and take it for a run. If the plug comes out black or wet looking, your problem is with the jetting. Take it from there.
Hi Rick, I wasnít sure if you still answered questions in Off or not so rather than doing the research to find out I thought Iíd give this a try:
Whatís the deal about a 1974 and a 1974 ½ Maico 400 and how do I know which one I have?
Dan Hilland

1974 Maico

1974.5 Maico
As you can see from the photos, the only real difference was the rear suspension.  The shocks were moved forward and the travel was dramatically increased. This was the beginning of the long-travel wars and for a period of time, and the Maicos were definitely at the cutting-edge.


Im 5'6 i weigh 145 im a girl and my family is a racing family i need to know what size bike i need i have a honda 100 but i feel its to small im 13 years old.                                   
Toni Young
For your height and weight, I would assume that your strength is above average. For trail riding, or just all around having fun on a bike, I think a Honda XR 200 or 250 would be about right for you. If you are thinking about racing, then a decent 125 two-stroke would fit the bill just nicely.

My bike was running so rich in oil that oil started spitting out the tailpipe. I went ahead and put a little bit of unmixed gas in the tank and swished it around a little then started it. It starts easier now and it runs a lot better. Still nice and smokey exhaust but no more oil spitting out. I should probably check the jets sometime so I know what mixture to make that'll correspond with the jet size. I just got the bike by the way so I'm still learning things about it.

One of the things you ought to learn about your bike is the year, make and model. How in the hell do you expect me to give you any kind of a rational answer when I donít even know what youíre riding? Does your bike have oil injection? Well, if it does, chances are the injection system is set too high. Or maybe the ratio of oil to gas that youíre using is all wrong and youíre leaning out the mixture by putting straight gas into the tank.
I have a 05 crf 230 an need new front forks im looking at a set of 2001 xr200 forks was wondering if the would fit or would it need mods an what mods those would be

Youíre really in luck, as we did a project Honda CRF 230 in Off a few years ago. In there, we spent several issues on options on frontend swaps and how to do it. To access any back issues of any project bikes that we have done, just go to and look up in the projects section and youíll find exactly what you need.  We still have our 2005 CRF 230 and ride it to this day.  With good forks and good shocks, itís a delightful bike. Stock, it leaves you cold.

Hereís a link to a list of many of the stories in that build:
Looking good.
Thanks for the kind words. Our series of project low bucks bikes has proven to be very popular with readers. What we are trying to do is make riding affordable. Not everyone can afford one of the new $8000 four-stroke hand grenades. There are plenty of decent low-cost bikes out there. If you use your head and pick wisely and are willing to do a little bit of work to make it right, youíll end up with a darned good ride for very low bucks. The Suzuki PE 175 you see right here is the perfect example. You can check out the recent story for the project here (Lowbucks, Part 4), and stay tuned for the wrap-up story next week. 

am looking for a 110 kit for a Yamaha yg1

Just what makes you think that youíre going to find a big-bore kit for a bike that was made in 1963, and a more or less street bike in actuality? I went on eBay and found many parts for that bike, much to my surprise. I even found piston kits at one, two and three sizes over stock. That would make your bike a little bit bigger, but certainly not the 110ccs that youíre looking for.

Hereís something to put over those bullet holes in your living room or garage: Four great posters of legendary MX bikes. These posters are 2 x 3 feet in full color and printed on heavy-coated stock. They feature: Bob Hannahís lightning bolt OW40 Yamaha, Joel Robertís famed RH 72 Suzuki, the red rocket Hondas of Brad Lackey and Jim Pomeroy, and the Three Decades of Suzuki poster. You can have all four for twenty bucks ($20) plus $7 for mailing in the US, in a sturdy protective tube. Info at

Have a question for Rick ďSuper HunkyĒ Sieman? E-mail questions to [email protected], Attn: Donít Ask.

Previous Donít Ask Columns:
August 2013

July 2013

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