ANY HELP WITH WHERE I CAN MODS FOR, YES A 90 CC YERF DOG WILL BE VERY HELPFUL. I'VE SEEN ONE PERSON'S POST OF HIM HAVING A K&N FILTER AND AN FMF PIPE. IM LOOKING FOR A GOOD PIPE, CLUTCH KIT, AND A 110KIT. BELIEVE IT OR NOT IT HAS A STRONG MOTOR AND PASSES MY OTHER SONS 2005 ETON 90VIPER DOWN THE LINE.

 

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Hey JBL,

Welcome to this forum.

Why the capitals in your post??? If wondering, capitals in posts mean you are yelling at someone - just in case you don't already know. If you post in capitals, it makes people hesitant to respond to your question...

For performance parts in Canada, your selection is "very" limited. Most mini-quad performance parts are shipped in from US or if lucky, sub distributed from another Canadian city. If getting parts shipped in from the US, be prepared to pay 2 to 2.5 times the US listed price. Good old dollar conversion, border crossing "brokers", double country shipping and Canadian sales takes loves your "shipped in" performance parts.

Please tell us what "region" you are located.. By knowing your location, some of us might be able to provide Montreal Quebec distribution centers and/or US sellers that are very close to your nearest US border. In you are in the US, we can direct you to the some Performance Consultants in your area.

Also, tell us why you want to increase performance and why type of riding you do. By knowing what type of riding you do and knowing what areas you want to "beef up", the experienced Performance Consultants might be able to recommend the best upgrade - for your unique riding conditions. Sometimes, doing inexpensive clutch mods are more critical then a loud screeming bigger bore engine. Especially in the lower ground speeds that involve soft sand.

Thanks for more info on your Yerf Dog 90, and how you use it.

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Sorry about the caps. But I live in the Los Angeles CA area and just getting around to riding in the local mtns. but have been to Pismo Beach a few times and look forward to our first trip this year to Glamis. But I've heard that the 2003 polaris has the same parts as the yerf dog, but I've only heard that from one other person in this forum. Thanks for your reply

 

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As a suggestion, contact Billy Holt at WRH Racing. He has different "Warp" bundles that could fit your 90. For more info on these bundled packages (for bottom end power and sand), surf: http://www.wrhracing.net/engine_kits

Note: There other Performance Consultants who have simular packages. Don't hesitate to check with those folks either.


To start, do investigate uni or other foam type filter upgrade. I've been told that foam filters work better then K&N for fine dust / sand riding conditions. Definately a Pipe replacement, cluth / roller upgrade (for higher rpm engine in sand) and a CDI upgrade (to go above factory MAX RPM limits). Adding higher PSI compression and performane reed installs with work great as well. When this is done, some carb re-jetting will be required.


There's a guy on this forum called Raptorlegs. He did some recent mods to his Polaris clone. I'm not too sure of the exact parts (obtained from Billy @ WRH Racing) but the end results was something about "his Polaris clone can not beat the tail off his 400ex". Not too sure if you want your mini to have that much power increase but if needed, it can be done.

Hope this helps....

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JBL,

While doing performance mods on your 90, there's a few safety things I'd also "highly recommend". They are:

1 - Make the front wider. With 1.5" wheel spacers (better yet, 3" A-Arms to reduce bushing and wheel bearing stress), your 90 will have less risk of tipping over. Especially on those sharp corners. If riding in soft sand, wider A-Arms would be much easier to control.

2 - Make a rear longer. Due to "more power" under the hood and your desire to do hill climbing in the mountains, installing a +1 or +2 Swing arm would reduce the risk of front to back roll overs. Especially with more power under the hood.

3 - Install DRLs (Daytime Running Lights). We installed DRLs and LED combo tail light on our Pred-90. I can tell you from experience, DRLs "do" reduce injuries. They allow a young rider to be seen much faster and thus, lowers the risk of head-ons with oncoming riders. If you want to install your own universal DRLs, surf: - Press Here -

4 - Install a univeral handle bar braket and driving mirror on the handle bars. Since a mirror could get snapped off by tree limbs or accidental roll overs, the mirror doesn't have to be a high quality. We have a plastic assembly mirror on our Pred-90. It allows my son to quickly see who might be sneaking up behind him. To me, this low cost safety install is worth it.

5 - Install a Whip flag. Our Pred-90 has a whip flag and yes, it does allow him to "be seen" much faster.


Hope these safety improvement suggestions help as well....

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spike 99,

I really do appreciate the help. I've actually spoken to Billy at WRH Racing and he is very helpful. It sounds like he's the only one I've been able to locate using this site so far. You say that there are other performance consultants, but If you have their web sites, I'd appreciate it. Sounds like you've fixed up your 03 Polaris, was it worth the money? Billy's mods will cost about a grand. So not certain if I should just get a new Kasea or Viper 90 with a 110 kit and pipe and all for 3 grand.. just a thought, but hate to spend all that money if I can get away with the yerf dog.

Thanks again Spike99

 

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I can't tell you why others upgrade their minis but I can tell you the reasons why we upgraded certain parts of '03 Pred-90. Each of our upgrades are based on Mechanical, Safety &/or more bottom end POWER increase improvements. Ideas that could be applied to your current mini and/or a new one.


Here's a list...

- Spring Loaded Chain Tensioner. I'm lazy. Hated adjusted our chain after every 3rd trail ride. Today, we tighten its chain in the spring and in the fall. And that's it. "No fuss / no muss" the rest of the year. Besides that, a chain under firm "spring" tensionion reduces the risk of it coming off and reduces chain / sprocket wear. Funny thing is, the '04 and up Pred-90's now comes with a factory chain tensioner. If your mini doesn't have a Spring Loaded Chain Tensioner, I'd recommend you install one. This is one of the best upgrades we've done to our Pred-90. Surf:

http://community.webshots.com/album/108721500mjHKZk


- Installed a rear push bar. This rear bar allows me to pull our Pred-90 in / out of the mud and snow. And, makes it much easier to load on our trailer as well. Much better then its factory 6" rear steel frame loop. And, this rear push bar also provides better support for our Pred-90 rear fenders. To me, a rear push bar is a "must have" on the Pred-90 brand. Surf:

http://community.webshots.com/album/284404321yqauIv


- Upgraded to Custom size sprockets and thicker Heavy Duty Chain. This lowered its tops end speed (from 30 down to 24 mph) but gave our Pred-90 much better "momentim" power on our technical trials. Especially for the ups / downs little hills that have a stream crossing in their valley. Surf:

http://community.webshots.com/album/284402100NAfkOS

Note: Many thanks to Billy Holt at WRH Racing for helping me with this upgrade.


- Designed / Installed Skid Plate. To me, a definate must for our technical trails. With a skid plate, the mini's low profile rolls over logs / rocks instead of its belly digging in. Surf:

http://community.webshots.com/album/284493780TASOxK


- Removed its Oil Injection. This reduced approx. 50% tension on the thumb control. Today, both my kids concentrate on driving instead of looking at their thumb, and trying to re-postion an over sore hand. Surf:

http://community.webshots.com/album/130997005nxNiAA

Note: Many thanks to Billy Holt at WRH Racing for helping me with this upgrade.


- Installed DRLs (Daytime Running Lights). To me, they are a must on all trail riding minis. I see the '06 Pred-90s now have DRLs. Not too sure if their '06 light assemblies will bolt directly onto the 03 - 05 Pred-90s. Finally, someone is realizing the increased safety with DRLs and combo tail light. Surf:

http://community.webshots.com/album/283371980xEWfck


- Installed Left side Driving Mirror. With a universal bracket and inexpensive plastic mirror, my son can see who may be sneeking up behind him - on our trails. Instead of turning his head around every minute (or so), he simply looks in his mirror. If someone is behind him, he turns his head to comfirm, he slows and pulls off to the side of the trail. The person goes by and he double checks for followers, then we continue on our way. This mirror dramatically reduces others sneeking up behind us. To me, this should be mandatory on all trail minis.


- Installed 53mm Cylinder / piston with 150 PSI compression (kept stock pipe, air box, carb and CDI). Installed this "internal engine" performance upgrade to obtain more "bottom end" punch for our mud, snow and sand conditions. Due to POWER sprockets and factory CDI, our mini only goes MAX 24 mph. But its bottom end has much more Power. Great for those "help - my rubber boot is stuck" type of mud trails.

Note: Many thanks to Billy Holt at WRH Racing for helping me with this upgrade.


- Installed Foot retainer bars on the running boards. A few times, my son's feet slipped off the Pred-90's running boards. To stop his feet from sliding off, I installed safety bars. I've also seen racers install simular running board lips as well. To me, this "higher lip on the running board" should be mandatory on all minis - that come factory with running boards. Surf:

http://community.webshots.com/album/284377392himalK
http://community.webshots.com/photo/...90216069eeexWK

Note: Many thanks to Billy Holt at WRH Racing for helping me with this upgrade.


- Installed 1.5" wheel spacers. If we had the extra dollars, I would have installed 2" A-Arms instead. A-Arms make the mini less tippy and doesn't put more stress on its bushings. Less tipping means less "roller overs" when doing donuts & fish tails. Our son hasn't tipped his mini since installing 1.5" wheel spacers on the front. From a lessons learned, I'd recommend 3" wider A-Arms to everyone. Being 1.5" wider with less bushing / bearing stress (compred to using wheel spacers) would be much better. Surf:

http://community.webshots.com/album/209852103mosGcm


- Designed, created and installed Custom foot brake. To me, all minis must come with dual control brakes. Some kids adapt to foot brakes and others to hand levers. From before and after comparisons, both my kids are definate "foot brake" riders. They control its new foot brake much faster & better then its factory hand levers. Perhaps one day, minis will be mandatory with dual control brakes. To me, they should be. Surf:

http://community.webshots.com/album/242848150eXxxII


- Installed Grease Zerk within the factory Swing Arm. For water / mud trails and/or lots of jumping, this grease zerk allows us to inject grease back into its Swing Arm bar / bushings. Thus, its chain keeps aligned because its bushings don't wear out "as fast". I'd do this "low cost with high benefit" mod again. For details, surf:

http://community.webshots.com/album/284538349PdZJcL



As noted above.... Our many mods were applied to make our mini SAFER and to create more POWER without making it go faster. Actually, our Pred-90's top end speed is now SLOWER then factory. On our trails, we rarely go above 20 mph. Our average down the straights is 12-15 mph. Most of the time on the trails, we're in the 5 - 10 mph range.

Sure wish the mini-quad factories would apply these safety items at their factories. Sure would reduce accidents and thus, create "lower accident stats to our sport".


To answer your question.... Each one of the above upgrades WAS worth it. Especially since our Pred-90 is in the midst of being OFFICIALLY passed down to our 8 year old daughter. All safety upgrades will benefit her - who will probably drive our Pred-90 for a very long time....

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Jbl Billy at WRH is excellent, as is Rich at Hetrick Racing Both those guys will do a good job with parts and service. for dunes a really good port job will work really well. I'd save the money from the 110 kit and get either Billy's, or Rich's pipe,clutching for about $300 and get a 20mm to 28mm carb kit for $250 and with $150-250 porting you'll have a screaming dune bike. For the dunes you dont have to have as much bottom end torque since the tires will spin. Stay away from the FMF its just a straight pipe and a silencer. The WRH,Hetrick make REAL power and have expansion chambers. The yerf dogs make good dune bikes since they have the 28 tooth rears sprocket and wide seat good luck.