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Thank you Ashley Putteman 

Sounds like you have some bad gas. Well, maybe not you but your bikes do. First thing I’d try is draining the gas in all the bikes fuel tanks and carburetors. There is a small screw in the bottom of each float bowl. Loosening this screw will drain the fuel out of the float bowl. Once you get some fresh fuel in the tanks, they should start normally. If the fuel has been sitting too long, it can create some build up in the carbs as it evaporates. This build up can be difficult to remove. This may require removing the carbs, disassembling them and soaking them in a carb cleaning solution. This may best be left to someone familiar with this procedure.  

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Thanks a lot, Chris DiSpina 

The TM 75 was only made a few years. I’d be a bit surprised if there were separate manuals for any of them since the bike never really changed from year to year. If you can’t get an aftermarket manual (Clymer or Haynes), I’d think any year Suzuki manual should give most all the info you need.  

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Thanks, S. 

You need to get a service manual. The manual will give you enough critical info to make it a very wise investment.  

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First lets get our symptoms straight. If the carb were to dump fuel into the motor, it wouldn’t run right due to the over-rich mixture. If you had "throttle hanging open" symptoms, it might be due to something other than the carb. An air leak can give the exact symptom you describe. Usually an air leak will give a more consistent symptom but that is the first place I’d look if you’ve ruled out carb problems.  

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I’m not familiar with that particular model. The pipe basically comes in two sections. The front chamber section and the rear silencer. The silencer may be a repackable type if it is bolted or riveted together. The silencer center tube, or core, will have holes over the entire length of it. These holes need to be clear and unobstructed before new packing is wrapped around it.  

The front section of the pipe can be cleaned with a variety of methods, some being bordering on dangerous since extreme heat is used to burn out the carbon residue. The safest way is to have it soaked in a tank of cleaning solution. Try an automotive machine shop first. They usually have a vat to soak car engines in before beginning a rebuild.  

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No, first thing I’d do is go back down to a realistic main jet. Try a 170 maybe.

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I’d run a good quality oil (Yamalube 2R, Honda HP, Spectro) at 40:1  

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Check your reeds first. Plus you might want to make sure the exhaust isn’t restricted. Is the pipe smashed? Check the silencer. I’ve seen a silencer break internally and create a restriction that won’t pass much exhaust at anything much over idle speed.  

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I am also considering a Yamaha TTR90, Honda XR70R, or XR80R for my nine-year-old son's first bike. Any recommendations? 

Also, any suggestions on riding gear, trail tools, safety and performance equipment would also be appreciated. 

Best Regards. 

PS You have a great web site. 

Oh, sure. Butter me up before asking a question that a book could be written about.  

The XR and the DRZ are better play bikes. More for just cruising through the woods. They both can be made to work better for faster trail work but there are better starting points. The KTM is a good bike but most people find the 300 is a much better size for woods riding. The 300 runs very well and will have more than enough power for you, regardless of your size or weight. The Husky is along the same lines as the KTM but is more finicky to set up and parts availability is always a huge question. More than once, I’ve had to wait literally months for Husky parts. I owned a Husky…… once. Never again. Personally I ride a WR 400 bored to a 450. I love the WR, even with a stock motor. It is a bit on the heavy side but doesn’t feel too heavy when riding it. The performance of the WR is very good when de-restricted. You need to determine if you have an objection to riding a four stroke. Some people love them and won’t ride a two stroke after falling in love with their four stroke. Some guys feel the same way about their two stroke. Overall, the KTM 300 is one of the most versatile bikes available that doesn’t do anything wrong or objectionable.  

For your son, a lot depends on how big he is and whether he’s ever ridden a bike with a clutch. The XR 70 is a semi-automatic (no external clutch lever to deal with). The XR 80 and TTR 90 have a clutch. This may be a determining factor. Unless he is small, the XR 70 may be too small for him. Either the XR or the TTR will suit him nicely.  

Riding gear. Boots, helmet, goggles and gloves are mandatory. Riding pants with knee and shin guards are next as is a chest protector. Some guys swear by riding with elbow guards but I don’t use them. Get a fanny pack made especially for enduro use. This will have small elastic bands sewn in to hold the tools stationary while you ride. Otherwise, the tools will flop around and be extremely annoying.

  Tools are another theory entirely. You’ll never be able to carry everything you might need, so I use common sense. I carry an 8mm and 10mm combination wrench, a 12x14mm open end wrench, an axle wrench designed specifically for a fanny pack (Enduro Engineering or Fredette Racing Products make these), and a small and medium flat blade screwdriver. I also have a long handle Snap-On ¼" drive ratchet handle. With that I have an 8mm, 10mm and 12mm deep six point sockets and a 6" extension. Plus a ¼" drive magnetic socket made for ¼" screwdriver bits. The bits I carry are a #1 and #2 phillips, a 4mm, 5mm, and 6mm allen head, and a #2 flat blade tip. I also carry a 6mm short socket for removing main jets. A small assortment of nuts, bolts and washers comes in handy. Some guys go so far as to carry a chain breaker and a flat repair kit. I prefer to run Bridgestone ultra heavy duty tubes (4mm thick rubber) for flat prevention and take my chances with chains.  

Performance equipment depends on the shortcomings of whatever particular machine you choose and what your priorities are.  

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Thank you for your help!!! 

This is a first. Rebuilding the crank and not putting in new crank seals. Before you change anything, you need to replace both the crank seals. A crank can seize because of wear and age. Sounds like your ’96 model was due for a crank from the amount of hard hours on it.  

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Thank You, Pat Smith 

Sounds like you have internal shifting problems. The clutch won’t give the problems you are experiencing. This is best left to a professional.  

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 Jason E 

Sounds like you had a seizure. You need to do a compression test to determine whether your compression is within Honda’s specs. I think you’re going to find some top end damage.  

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A shop manual will be well worth the money you spend. Get one.  

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Thanks. Nate.

  Nope. The ’88 and ’89 RM 125 take different reeds.  

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You need to pick the bike you want and have it lowered. This is by far the best way to get the results you want. Lowering the suspension needs to be done internally to be done correctly with no adverse problems (safety or handling) stemming from having it done wrong. A good suspension specialist should be selected for this. I know Jeremy at MX Tech can do this. He’s done plenty of these. Try www.mx-tech.com for more info.

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 Thanks so much! Jay Stephens

  I’d check the main crank seals. These can leak, even with that low a mileage due to age and can give the exact symptoms you describe.  

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-Kurt B 

You have an air leak somewhere. Use a can of aerosol carburetor cleaner and spray around the cylinder base and carb boot with it idling to help pinpoint your leak. Also remove the left side case cover and check the crank seal under the flywheel. You can use the carb cleaner here also.  

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Scott McEnespy 

The ignitions should interchange. The only difference will the be absence of the lighting coil for the EXC lighting. The lighter flywheel will help with the snappier throttle response but it’ll hurt in greasy woods conditions. I think I’d get the jetting sorted out on the EXC before I ruined a perfectly good SX. A stock EXC runs very well when running up to its potential. You might consider a few mods first. I know the Delta V-Force reed works great on the KTMs. A very good mod for the money. Set the reed petals on the low tension setting if you try the V-Force. And as always, rejet to compensate for any mods you do.  

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Thanks, STeWART Bain 

Yes, that was supposed to be fastened to the cylinder. The Yamaha service manual will be a big help. Get one.  

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Your low speed jetting is too rich. Leaning the pilot jet will be a good place to start. There are any number of good jetting guides on line. There is a good one on Eric Gorr’s website. Go to www.eric-gorr.com for more info.  

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THX MAC. 

Use the aerosol carb cleaner trick explained briefly above ( UNNECESSARY HIGH REVING '78 TS-250C SAVAGE). I agree, you have an air leak. Don’t overlook the crank seals.  

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Thanks for your help, Kenn

I’ve never heard of a shock called a "Stiffie". You have a shock with a "Stiffie" sticker on it. Any decent suspension shop should be able to look at your shock and tell what kind it is. Parts are available for any shocks that are intended to be taken apart.  

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Thank you for your help. -Ian

I’d recommend at least a 125 to help with your gearing problems.  

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Any help would be great...gary 

Sounds like you have a bearing going south. Yes it is fixable but may get expensive. I’d look closely at the bearing the main transmission shaft rides on (the one directly behind the clutch). Also look at the needle bearing the clutch basket rides on.  

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Thanks for any info! AL 

Your KX is a very good bike. Good power and fairly reliable as far as KX’s go. The previous owner upgraded because your KX is now 4 years old (an eternity in dirtbike years). Sounds like he did most of the mods you’d need. The V-Force does great for an all around improvement in power output. An aftermarket silencer won’t make any earth-shattering changes in power. Gear oil. I’d use whatever makes the transmission shift best. Chances are that will be Type F automatic transmission fluid. I don’t care what the printed mags say, do NOT use Dexron fluids. Type F is the one you want. The parts guy will just shake his head if he hears of you using ATF in your gearbox. He wants you to spend $6 a quart for an oil that makes it shift worse. ATF works exceptionally well and protects more than adequately as long as it is changed before it gets burned from high heat. Some clutch abusing riders need to change it a bit more frequently since they generate much more heat with slipping the clutch. Even without a lot of clutch abuse, I’d change ATF every other ride or so. The nice thing about it is that it is so cheap you can afford to change it frequently. One of the leading causes of transmission problems is contaminated oil. Changing any oil frequently will help eliminate that and also prolong clutch life. Spectro is fine but mix it at 40:1. The BR8EV plug is a waste of money. I’d run a BR7ES unless you’re running continued high rpms (desert racing or a very fast mud race) and then go to the BR8ES. The cheaper S series plugs are more resistant to fouling, regardless of what the manufacturer claims.  

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THANKS Sam Strickland 

The ’96 KX is more than adequate when in good condition. For $600 there is something very seriously wrong with that bike. I think I’d shy away from that one. You’ll end up regretting it.  

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Thanks Guy 

It isn’t "normal". It is due to being jetted too rich. With a few hours on your CR, it is broken in and can be run as hard as you like. Your low speed jetting is too rich and needs to be corrected before the spooge will stop. A one step hotter spark plug will also help reduce/eliminate the spooge.  

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Gary 

The carb could be gummed up or possible some corrosion has developed on a critical electrical connector. My money is on a gummed up carb.  

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I have noticed that the front sprocket has begun to wear, giving the teeth a shape similar to an ocean wave. Is it time to get a new one? Can I reverse it to make it last a few more weeks while I get a new one? 

Thanks - Hawk 

Follow KTMs recommendations for chain tension. Check your owners manual. Your sprocket is getting ready to break the teeth off. Change your chain and sprockets together as a set. Reversing the front sprocket will only result in the teeth breaking off faster.  

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The clutch is dragging. That can happen from any number of causes. Dirty oil (or the wrong oil), warped clutch plates, a grooved basket or hub are a few of the more common reasons to check for. If your clutch cable is stretching, that can aggravate a dragging clutch. You may have a combination of things adding up to the problem your having.  

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Thanks Paul 

Welcome to the club. If you find the magic answer, let everyone know. Any of the aftermarket pipes can help but mostly just rearrange the power output. I’d try a different reed cage. The V-Force is a proven product. Chances are you’re going to end up sending the cylinder off to get ported to get acceptable results. Eric Gorr is one of the best in the business for porting as well as being one of the most reasonably priced. A 2mm overbore is a great way to get some much needed power out of that motor. Check with Eric at www.eric-gorr.com for more info. A call on his phone will generally result in a quicker answer to your question.  

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With all the baffles in place, the XR 250 will run that way. If it had contaminated fuel, it would run more erratically. Your ’86 XR 200 was no slouch. That bike was intended to compete with the likes of Kawasaki’s KDX 200. Your XR is meant to be more of a play bike  

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You need to make sure the motor is in good overall mechanical condition. Once that is done, make sure the silencer is in good condition (fresh packing and core holes are clear and unobstructed) and then concentrate on getting the jetting sorted out. Your symptoms describe a worn out top end to a tee.  

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I am 6', 170 lbs. (no gear). I ride pretty aggressive northeast woods trails that really are a mix of every imaginable terrain. My primary concern though is to have the best "woods" handling possible, as that's the majority of my riding. If you could possibly give me a ballpark setting to get me going and I can fine tune from there, that would be outstanding! 

Also, I have been unable to find all but the most basic information on the RMX. I know they have stopped importing them, and I love the bike, but would I be better off keeping it as it's a respectable bike, or should I sell it while it's still in great shape and possibly purchase something else? All I was able to determine before I bought it was that it is essentially an RM factory tuned for enduro style riding (which is exactly what I wanted) and that it is all but bulletproof. I have the majority or major aftermarket items including a full exhaust. I have removed the airbox lid (what an improvement!) and I have heard about replacing the head gasket with an RM gasket to increase compression. is there anything else I can do to help squeeze more power out of it w/o doing a full rebuild? 

Thanks! Morgan 

The head gasket for an ’89 RM 250 will help bump the compression to give a substantial increase in midrange and low end. An aftermarket reed cage can also help give a good performance increase. Your suspension can be made to work and work well. I had a ’96 RMX and had Race Tech Gold Valves in the forks and shock. They made a big difference. One thing I did was run the forks up in the triple clamps to help cornering. I had them raised up 10mm over the top clamp. But it needed a steering damper to compensate for the added instability from the sharper fork angle. But that thing cornered like nothing else. That bike would slice and dice through the woods like few other bikes. The specific suspension set up depends on many variables such as your weight and what some of your priorities are (plush vs. firm, etc.). Start out with the rear spring sag set to 100mm, set the compression clickers a bit on the soft side and run the fork oil at the high end of the specification.  

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Thanks! Wayne - Vancouver B.C. Canada

There really isn’t any cost effective way to lengthen the suspension. Your best bet is move up to an 80.  

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I'm seriously considering buying a pipe but am confused about which type; I mostly do trail riding but am starting on the motocross tracks. Is it true that an aftermarket pipe can give an increase of 9 hp? If that's correct that's about a 20-25% increase in power? Also if I do buy a new pipe would I be better of buying a new aftermarket muffler to go with it, or stick with the stock? I wasn't considering the muffler until a short while ago when my present muffler blew out everything but the outer casing. Apart from being obscenely loud I noticed a sharp increase in power especially in the midrange, until then I didn't think mufflers really make such a difference, what do you think? 

Also, what do you think about Boyesen reeds, do they make a noticeable difference? What about cylinder and head work, someone told me that modifying the engine would result in a shorter engine life, is this true? Would any of these mods make the bike more unreliable or put a greater strain on the engine? I plan to hold onto this bike for the next 3 years so I don't want to run into expensive engine repairs. Your opinion would be greatly appreciated. 

Thanks, Alex Ritchie 

The stock CR pipe is one of the best available for overall power output. There isn’t a pipe made that’ll give your CR anywhere even remotely close to 9 hp gains. Get a good aftermarket silencer and keep it repacked properly. An aftermarket reed cage can work wonders also, but only if you rejet to compensate for the mods. Cylinder and head mods are a very good value if done by the right person who knows what they are doing. They give good increases in power with virtually no decrease in reliability. The one mod that can reduce crankshaft bearing life (among other things) is increasing the compression too much. This can result in having a hand grenade that is waiting to go off. Head mods are generally done to help reduce/eliminate detonation.  

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Tell me what you think... DG 

I think you need to get a service manual and check the electrical components according to the manual with it in a failed state. In other words, ride it around until it is acting up and then check the resistance according to the chart in the manual.  

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