Ok, I might as well add to the wealth of information out there. Here we go with my review:

First of all let me say this, my 8 yr old 55lb son has perma-grin. He has had it out 5 times. 2x's at the sand dunes and 3x's on some 4x4 two track roads close to town. I'm not a proponent of sand dunes as we generally ride in the mtns (don't open until May 15th), but let me say this, the dunes are a great place for a youngster to gain some confidence in the forgiving sand. He's quickly learned angles, appropriate speed, body placement on the quad, and what his limits are. So with that said....

Likes:
-It fits my 8 yr old perfectly. He can stand up and shift his weight as needed.
-It came with a helmet, flag, and safety video. Helmet is not a bad looking black helmet. Better than my "old mans" helmet.
-Plenty of suspension travel in the shocks. When I sit on it at 180lbs, it squats about 2/3 of the way down. Soft enough to help him out. He's never complained about being banged around. Today at the dunes he used all 4 inches of the suspension travel on many occasions and it held up well.
-Chain tensioner.
-Complete floor boards. He plowed through a whole lot of mud today (on the way and back from the dunes) and walked away with only dribbles on his shoes. I even let him back in the truck ;-) ...and no troubles with water and mud in the cvt/intake area. I'm sure there's deeper water in the future for him to see if the floor boards are the actual limit for water. I'm sure they are.
-No maintenance--at this point.
-Speed. I clocked him at 32 mph with my SP 335 speedometer. Note...just had my sensor replaced last month for the speedometer. It does well once momentum has been established. I couldn't believe it went that fast!!!
-Tires. They did great in the mud and dug a quick whole in the sand (on many occasions). Plenty of traction.
-Horn. Yes, the horn. If I've gone ahead of him and he needs me, he hits the horn. Sure beats yelling.
-At the dunes...the two stroke is a blast. He has more fun there as it is essentially made for gettin' after it with the throttle. Plenty of power for him to get anywhere he wants. Just rap it out and he's there.

Dislikes:
-No reverse. If I could turn the clock back, I'd spend the extra for it. No thinking twice about it.
-No lights. Hasn't been a problem yet, but we often go for night rides or get in late when camping. I'll see how the future goes.
-Stiff throttle. At the dunes it's less of a problem as he's on-and-off the throttle. Trails...a problem.
-Little low end torque. He stopped in a rut about six inches wide and deep. Not stuck, but stopped. The left tire was the only tire in it. He tried to accelerate out of it, couldn't. I'm sure he took a ride or two off the CVT belt trying to get the quad to go. I preach theories of momentum to him now. He cannot stop on a hill, if so, I'm pushing or pulling. There's little slow and go torque in that 2 stroke. ....what do I expect, it's a youth 90.
-Racks. I thought he'd use them. "...no dad, you carry it on your 4wheeler".
-Decals for a speedometer. No need. It's just going to peel off someday.
-More clearance, Clarence. I've got 5 inches, that's good for most youth quads, but it's still not enough. He got high-centered twice today. However the tires are as big as they should be. I have to teach him how to negotiate 5 inch plus obstacles.
-Electric Starter. It's been finicky lately. For the last two rides it didn't work. May have been that battery sitting in the showroom for a yr...which I think it was. It starts now. It's also warmer now and batteries like warmer weather. Go figure. Kick start works great.


My to do list:
-Change out the sprocket to help out with the low end torque. Or remove a couple rollers. Haven't decided as of yet.
-Purchase some lights from Warn as they look like ones that would fit.
-Add an extender to the throttle or something of the sort. I'll have to look around. I bet the dealer may have an aftermarket setup.
-Next month have the dealer change out the oils and check the battery while he's got 'er in the shop.

Wish list:
I'm holding my breath for some manufacturer to engineer a 4 stroke 90 with 3 gears (reverse included), lights and full floorboards that is not a "knock-off" brand. That' the ultimate quad for our riding needs. I'd sell the SP 90 for one in a heartbeat. Mrs. Psycmike might have something to say about it, but I'd sure try.

There ya be. Hope it was helpful or informative.
For being good readers, here's the pics from my Moab, Utah trip last month. enjoy.[img]i/expressions/face-icon-small-smile.gif[/img]
http://client.webshots.com/album/330675273Mvsoaf
...but wait there's more....http://client.webshots.com/album/319761143hLQQzu

 

Hi,
I have a 04 predator 90. Same thing different plastic. Some of the problems My son has had with it are:

1. the spark plug cap. The cap on the wire has a bad connection since day one. Fix- got a new one NGK no more problems.

2. Low end torque. Fix somewhat fix, i replaced the reeds with power reeds from boyesen. What a difference. I also disconnected the oil injector because it was running rich. This woke it up.

3. Swing arm guard. Im looking at getting a new one. The stock one is beat to hell and when it bends it hits the chain tensioner. Fix- get a new one.

4. Chain tensioner wheel sticks. I clean it every ride and lube it. Fix- get a different brand then polaris for a chain tensioner. Maybe hotseat.


Thats about it. Nothing major. The only time he could not ride with it was because of running rich and fouling plugs. Once the spark plug boot was replaced never had a problem. Also never fouled one after that and the oil injector was removed.

If you need any help let me know.
Bob

 

Bisho 12,
In your post you mentioned this:
Pardon my ignorance, but what are reeds? Are they anything like rollers? Do they allow you to maintain a slower speed with higher rpms to negotiate techinical terrain? That's what I need for my son to ride many of our trails that are technical. How are you cleaning the chain tensioner? Did disconnecting the oil injector help with the stiff throttle cable? I probably won't do that, but you never know.
Thanks for your input.

 

Reeds are the intake valves on a 2 stroke. They are under the carb. As far as the lower speed higher rpm, i believe its the clutch that will do that. Your best bet is to ask spike about it. I have not changed the gears yet. The oil injector i think is a must.

As far as chain cleaning or tensioner cleaning i use a wire brush. The stiff cable is not a issue for my son. He has never said anything about it. When i disconected the pump all i did was take the plastic drive gear off the pump and put the pump back on. The cable is still working on it but no oil tank no lines. You have to plug up the line on the carb from the oil injector too.

 

Thanks, bisho 12.
There are only a few things I'm willing to tinker with for two reasons: My mechanical prowess is suspect. Secondly, if I can find a 4 stroke that meets my our riding needs better than this SP 90, I'm on it. Not only that, I have a tendency to screw things up once I begin working on them. You've seen it before, take the box of parts to the mechanic and ask him to put it back together for ya. That's me. I've had some discussion with posters regarding rollers and taking 1-3 of them out and that making a difference on the low end power. The trails aren't open yet (May 15th, too much snow) so I'll get it out then and see how it does on our trails.
Again, thanks for the input.

 

.

Reed cage is located between the carb and the engine. It bolts onto the engine and is behind the intake. The reed cage holds the reeds. Many say that reed upgrades will allow 15% - 25% more mixed fuel to enter into the engine. The end result is snappier throttle response and a litte more HP. Many also say that that on the Polaris 90 models, the air flow bottleneck is the Pipe, Air Filter, Reeds and Carb. Air filter is the biggest bottleneck. If you upgrade the pipe and air filter, some upgrade the Reeds. Some even upgrade the factory carb to a 20mm in order to gain even more airflow through the engine.


To obtain more details of how a 2 stroke engine works and it's Reed postion, surf: http://www.atvriders.com/articles/twostroke.html

To view what a Performance Reed block looks like, surf: - Press Here for picture -


Hope this helps...

.

 

.

To give your Polaris more "bottom end" power, there's a few things that can be done. They can be done individually or combined together. Each has their pros / cons:

A - Change the roller weights. This is a change on the CVT system. Basically, it makes the engine rev higher before engaging its belt drive. For someone who's looking for 0 - 8 mph "more power", this is the best option. However, it does involve changing its CVT system. Many new mini-quad owners are uncomfortable with this low cost "internal adjustment" change. But if you go slow, many say this is your best 0 - 8 mph gain. Espeically for the trail riders.

B - Change the sprockets. Smaller on front and larger on rear. While doing this, should also replace its "average" quality chain and install a higher quality HD (Heavy Duty) chain. This is a good change for folks targetting 8+ - 20 mph "power gain". The HD chain upgrade is also better for heavy weight riders - like my 135ish lb 10 year old son. This is an "external" change and easy to do. But, it gives very little 0 - 8 mph gain. At 0 mph, there's NO power gain at all. At 8+, the stock engine has higher RPM and thus, has better momentum on the trail (when above 8+).


There are other upgrade options that will help with bottom end power as well. Upgrades such as Air Filter, Pipe, reeds, bigger carb, higher compression stock engine, clutch kit, big bore head/cylinder upgrade with higher engine compression, etc. As a suggestion, contact a Performance Upgrade Consultant " like Billy Holt at WRH Racing at billy.holt @ wrhracing.com " for experienced upgrade recommendations. Each upgrade option / parts bundle has their own pros / cons and isn't always best for all "trail riding conditions". For example, pipe upgrade is great but terrible if you have a very small back yard, or lots of people population in your trail riding area.


Hope this helps as welll...

.

 

Instead of throwing the baby out with the bath water, you might talk to your dealer about doing a few upgrades for you. While a pipe and clutch mods aren't cheap, they would more than give you the power you're looking for.

Hey I can ride my kids up the ramp into my Ram from a dead stop, spinning like crazy all the way. Probably overkill for your purposes, but the potential is there.

 

raptor legs whaat springs and weights are you using?

 

Been a while since the install, but yellow torsion spring, white clutch springs(on aftermarket clutch) and I think 5 gram rollers.