Ask Sparks Racing

Which sport quad will hang with a built 400EX?
I had a deposit on a Raptor, but as soon as my buddy bought a 1999 400EX and had a 440 big bore put in it, I realized that a Raptor wouldn’t keep up with it. He has only raced a stock Raptor, but it wasn’t even close, in both drag and up Sand Mountain Not to mention, I like the Honda’s suspension better . How reliable is a 440 engine? Would an aftermarket pipe, properly jetted cab and filter system on a Raptor make it any closer? I am not brand loyal, I would buy the best quad available, should I wait and see the finished Cannondale? How soon could I expect to see something from Kawie, Suzuki, or a manual Polaris? I want to buy before the summer hits, but I am thinking that maybe I should wait? Can anything hang with a 440EX?
Thanks,
Kammon

Certainly the 400EX is a nice package and the 440’s run very strong. The Raptor has many nice qualities too. When you get to pepping up the Raptor with exhaust air box and jetting, it runs much stronger. It’s extremely receptive to these minor mods. In fact, you probably wouldn’t even recognize how it runs, it is that much better! Suzuki has certainly announced a very exciting quad for this coming spring. As far as any other company coming out with any great sport quads, your guess is as good as ours. There are a lot of options beginning to present themselves and making the right choice is part of the fun. It’s a great time to be an ATVer!
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A faster Honda 400EX
I own a ‘ 99 400EX and want more performance out of it. A K&N Air Filter with a vented box, carb jetted with a 152 main and 45 pilot, a complete Aftermarket exhaust is the only things that I have done now. What is your opinion on a .90 over kit. Is that too much to expect engine longevity, or would you settle with the .40 over. I have also heard that the stock rev-limiter runs the engine about 8200 RPM when it is capable of running almost twice that. Where could that be found along with bigger oil cooler to keep the engine running cooler.
Thanks,
JOSH FROMME

We find that .080 (416cc) is very reliable as long as you do it correctly. First make sure that you use a high quality piston, and the cylinder is bored and honed by someone with a good reputation. We have seen many less than quality bores sent to us by customers saying that they had some friend of a friend who used to be a mechanic do the boring. The stock rev limit is a little low and there are many aftermarket companies that sell CDI’s that rev over 10,000 rpms. An oil cooler is not a terrible idea, but the oil is not where the heat problem is on the 400EX. The 400EX desperately wants to be water cooled, but that is a costly modification. The solution is to cool the motor with race fuel. High octane race gas actually helps a motor run cooler. Now a stock motor doesn’t want the same octane that a 440 with 12.5:1 wants.
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CDI box dilemma
I have a ’91 TRX 250X. It has an aftermarket 280cc bore kit in it, aftermarket
all around cam and the aftermarket clutch and I was wondering if the stock 400EX CDI box would work with my 250X because I can’t rev the motor out and get the full use out of my cam with out the rev limiter kicking in with my stock 250X CDI box. Is it possible? If not, where could I get a CDI box for my 250X?

I don’t believe that the 400X CDI will work well on the 250X. There are High Rev CDI’s available. Shop around aftermarket performance shops to find one.
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Suicide jump threats on an ATC 200X
Sparks racing,
What’s up. I was just wondering I have a 1986 200X. It’s in mint condition. I have done nothing to it and the previous owner had no use for it so they did not ride it and kept it in storage. My question is if I should be able to jump it with no problem. Or should I get new shocks. The shocks are really good on it; there is a spring shock in the back and air shocks in the front. If I can jump what do you think should be the biggest jump I should take before it’s to hard on the machine.
Thanks Jake

I wouldn’t personally jump a 200X, but I am sure Curtis would go crazy on it. He won many races and got plenty of air on Honda’s mighty 200X. Jumping can be fun and dangerous. Whenever you ride, you want to make certain that your machine is in good safe operating condition and as far as jumping, whatever you feel comfortable doing should be your limit.
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Yamaha Warrior Mods
Sparks Racing,
I just got into the world of ATVing, and I am really starting to get into it and like it very much. I would like to know what could I do to my Warrior to make it have more power and speed. What parts are the best to make it
have more power and speed?

Well there are definitely performance shops out there that can help you make your Warrior run better. It can benefit from exhaust, carburetion, air filters etc. etc. The list could go on for some time. Find a reputable performance shop and talk to them.
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400EX carb question
I have a 400EX and it has a 440 kit 12:1 piston, over size intake valve,
port and polished, Aftermarket cam, Aftermarket exhaust, Aftermarket CDI box, 36 mm Lectron carb. I was wandering if that carb was better than 39mm Kehin PWK carb. Like that one on the Yamaha YZ400 because we have both but we are having a lot of difficulties with the Keihin. At first the engines sounds fine but when you start getting in it wants to pop on top end. If you have any ideas let us
know.
Thanks

I would consider the choice that Yamaha made for their YZF426 and the choice Honda made for their CRF450R as a good recommendation. If your FCR is popping, it could be lean and sounds like it needs to be jetted.
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A better 400EX pipe
Dear Curtis Sparks,
I have recently bought a TRX 400EX, and I really don’t know which exhaust brand to buy and I would like to know which is your choice on the best all around performing exhaust. If it’s not to much trouble, could give me the two best exhaust system. Also what other motor mods should I do to it if I intend to start racing. Thanks with any help you can give me.
Dominic

Well, that is a tough question to answer. I would say do some homework to find the best exhaust. Read some magazines, (ATV Sport did a big 400EX pipe shoot-out a few months back). Ask some other riders, look at what the fast guys are using and then call some of the companies that seem to be at the top of their game. Take your time, and do some research – exhausts for the 400EX can $450 – $500.
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Replace the valve springs too?
Dear Curtis Sparks.
I plan to race a couple of TT races this year. I have a 400EX. I just put a cam in my 400EX. Is it necessary to put new heavy duty valve springs in. Some people say that it will ruin the cam. Is this true or not?
Thanks
Jeremy Berger

Each cam will have a recommended spring kit. Sometimes that will be a stock set up, sometimes that will be a heavy-duty set. Check with the shop that sold you the cam for their recommendation.
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Which reed cage is best for the R?
I have a ’88 TRX 250R, mid range porting, bottom-mid pipe, 35mm Air Stricker. Now my question is what reed cage would you recommend? I have a ’88 CR 250 reed cage & a Boyesen rad valve (04A). Which one will work better, or would you recommend something else? I am looking for a good MX package.
Thank you for your time,
Ernie

I would think that you would get better performance from the CR assembly, but you can answer that question simply by running both set ups. Whichever one you like best, well it is the one for you to run. That is basically how a performance shop figures out these questions. Just try it and see how it runs.
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Getting a better holeshot
Dear Curtis, I own an ’86 250R. I have a lot of trouble getting off of cement starting pads, but my friend won’t tell me how he does so well. Could you please tell me what the
problem is. I am running a stock rear sprocket and a 14 tooth front. I
run 18-9.5-8 turf tamers on the rear. I run an aftermarket exhaust with a silencer, a stock carb and a K&N air filter . I am 5’9″ and 165 lbs. Please
help. It’s greatly appreciated.
Thanks,
TOMMY METZ
007

Lots of horsepower and lots of practice. As far as specific tips, watch the guys that get off the pad well and ask them how they do it. Usually if you watch and ask long enough, you will get a good idea of how to do it. And make sure to practice often. Considering that at no other time during a race can you pass 19 guys at once, the start is very important.
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Wanta be racer
Hey I’m wanting to get into quad racing because I have a 250R and my friend Hollie Shartzer keeps on telling me that I should race. I know I can beat almost every body out there but I don’t think that my 250R is going to be competitive Could tell me the basic parts that I should buy so I can get into racing.

I would ask Hollie. She has done well for herself this past GNC season getting her first TT national win. Keeping your quad in good running condition is the most important part. Beyond that, you will want more horsepower and better suspension.
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More out of my Recon
I have a 2000 TRX 250 Honda Recon and I want to spiff it up. The only thing that I found I could do to increase performance is an Aftermarket exhaust. Do you have any ideas on how to make my quad better?
Sincerely,
Mark

I am sure that there will be performance shops that will offer some modifications for the 250EX soon. I would expect that an exhaust system would make more power.
Ask Sparks Racing

A better pipe for my Banshee
Hey guys, WAAAZAAAAAAAAAAAAAAP?!
First of all, awesome site! I’m 14 years old and ride a 1996 Banshee. I have some questions about pipe/silencer kits. I ride in the woods (but not tight, technical woods) mostly, and occasionally open fire road type places. I currently live in NJ and will be moving to Rhode Island this summer. Sound output is a concern, but not the first priority. Should I buy a low, mid or bottom pipe? Do you know if Rhode Island has sand dunes, if so I would buy the top end? Should I really spend the extra money for a spark arrestor? I wont be able to buy two sets, so the correct set would be crucial. All the manufacturers claim their pipe kit is this best, but what brand/model would be best for me? Is there anything else I would have to buy with the kit? One other thing, which company has the best-looking, longest lasting chrome? On a particular aftermarket company’s website, they admit the chrome will flake (not much of a selling feature).
Cameron “Barrel Roll” MacDonald

PS- I Got my nickname from catching a sapling tree under my right a-arm doing 30 mph, and doing a complete barrel roll in mid air, The quad landed fine, but I hit the ground so hard my shoes flew off. BE SURE to use the chin strap up on your helmet every time you ride, I didn’t and the mouth guard on my MX helmet split my lip, ripped the crap out of my nose, and knocked my unconscious for 5 minutes (blood pooling in my eyeballs was not a soothing site from my mom)

I can say that the Banshee in desperate need of bottom end for most trail riding. I am not familiar with Rhode Island, but I can tell you all about California riding areas. I would only recommend a sparks arrestor if you ride in an area that requires spark arrestors. Of course every company is going to claim that their exhaust is the best. I can’t recommend a particular companies exhaust over another. Just do your homework and find the one that is best for you.
Ask Sparks Racing

Let your Raptor breath
Hey sparks, I bought a new Raptor about a month ago. This past weekend I put an aftermarket pipe on it. I love the performance increase but now it runs like it needs a jet kit and an air filter to help out the pipe a little bit. Do you know of any companies that currently make a jet kit or filter for it? Also I was at the track this past weekend and my Raptor backfired and blew the carbs out of the rubber boots, and its never done it before what do you think caused it?
Thank you for
your time.

The Raptor exhaust and air box are suspiciously small. I say that because I can’t imagine Yamaha would build this great machine and put an undersized exhaust and poorly designed air box on it without a good reason. I think Yamaha was trying to detune the motor a bit. So the Raptor will respond really well to oversized exhaust systems and larger, better-designed air boxes. As the backfiring goes, I understand that the automatic decompression on he cam operates when the motor is running below 850 rpm. If your bike’s idle is set below 850, then it will probably backfire. Also, the carb clamps can be tightened more if you shorten the spacers on them.
Ask Sparks Racing

ATV Scene is proud of our collaboration with one of the most successful, knowledgeable and respected race teams in the history of ATV racing! Curtis Sparks has brought a lifetime of know-how to the sport. Before, during and now after his personal racing career, he has fine-tuned Sparks Racing’s products and services resulting in some of the best performance products available on or off the race track!

Here’s your chance to get your ATV to run like a top pros. If you have a technical question (or any other question) for Curtis or any member of the
Sparks Racing Team, simply click on the e-mail link below and submit your question. Your questions will be answered in upcoming issues.

(Please try not to aim your questions directly about Sparks Racing products. Instead be less specific so your question can relate to all ATVers – not just ones that own a particular Sparks Racing products).

Send your question to asksparksracing@sparksracing.com. For a look at what’s available from Sparks Racing, check out their web site at
www.sparksracing.com

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