OK - I knew my Trail Blazer wasn't going to break any land speed records, but now I've really had it. Went to the local riding area last night, they have a nice 1/8 mile drag strip. Some kid was out on his totally stock Blaster looking for a race. He looked my way and I thought "this should be fun, I think I can actually take him..." - famous last words of a sucker! If it had only been a 1/16 mile race I might of had a chance as I pulled him off the line big time - but come time for top end..... well, let's just say I was done and he kept right on screamin. Before all was said and done, he took me by 4 lengths.

Now - in my not so expert opinion, I think my TB is running pretty good right now. The jetting seems good and all. So how do you get some top end out of this swine? If all the answers involve $1000 and 3 trips to the machine shop.... forget it - I'll save my money and buy a 400ex.

 

00TB250,

Try a VM34SS Mikuni carb on your machine. You can usually pick one up for less than $200 new and usually as a give away from people who have moved on to bigger and better carbs on their 400s. It'll really wake the machine up. To get the most of the carb, I'd recomend a U.F.O. (Ultimate Flow Optimizer) from Thunder Products. Hot Seat sells them for around $30. It is $30 well spent, while it doesn't add more horsepower, it does make a 34mm carb more efficient and makes the engine quicker to accelerate. It basically makes the round slide carb act like a flat slide carb.

I had to gear down from a 12/42 to a 12/38 combo to make the machine less wheelie prone. Even with the gearing change it still wants to wheelie. The gearing change will give you extra speed without losing and quickness. In other words, it'll be just as quick (time wise) as a stock Trailblazer, just a lot faster (more MPHs). As yours is a concentric drive model, you have it even easier. You can change the front sprocket up one tooth and get basically the same gearing I have.

Porting is also an option, as are head mods. Neither of these alone will break your bank account. Just be prepared to pay for premium gas. If you go with a porting or head mods don't forget the Wiseco piston. The stock one won't stand up to all of that pounding.

Hope this helps!

 

Mike, what are your thoughts on adding the 34mm carb without any porting or head mods?

 

Just a couple of quick comments;
Mike geared his quad UP, not down as he said. Going from a 42 to a 38 tooth rear sprocket is gearing up.
Second, while modifications to the head, (I assume he means shaving the head to increase compression) will create more stress on the piston, porting won't. What porting will do is give you more power at higher revs, at the expense of power at lower revs. Higher compression will give you a boost across the rev range.
A cheap and simple tuning trick with two-strokes is to double up the base gaskets, which will raise your intake and exhust ports. You have to shave the head to bring the compression back to stock, but unless you shave alot you can use your stock piston. This will give you a boost at higher rpm as well, but it's alot cheaper (though less effective) than a porting job.
Porting will give you a very good gain, but you have to be sure and find somebody who knows what they're doing, cause if not they could screw it up and you'd lose power.

If there are many snowmobiles around where you live you should be able to pick up a used carb for really cheap, and yes, it will help alot even without the porting.

 

don't worry about top speed. You have better acceleration and more power. That is more important than top speed. How often do you ride at top speed? probably not too much!!

 

It's just the idea of getting beat by some kid on a 195cc quad....

 

I wouldn't let it get you down. Blasters have a six speed tranny, and weigh about a third less than the "Blazer". If you really want to get smoked by one, challenge him to a race through tight woods.

 

00TB250,

Yes, I heartily recomend it. In fact Celeste's Trailblazer doesn't have porting or head mods and the before mentioned gains are without porting or head mods. I've had my Sport ported and the difference between the unported and ported was night and day.

thenewfiebullet,

You're right, I geared it up and not down. I keep getting the two confused for some reason.

Second, I believe that the porting could cause a piston failure with the stock piston for two reasons. Remember the ports are not only higher, but wider too. If a ring were to get caught in one of the ports it could very well lead to a shattered stock piston (along with the ring). The softer forged pistons will surely bend but not break. I've seen the harder cast (stock) pistons punch a hole through the cases, especially when they jam between the crankshaft and the case.

Next, if you create more power (it doesn't matter what the RPM range is) there will be a significant chance of failure with a stock piston. Most of the problems I've seen happen, come at higher RPMs that most aftermarket pipes operate in. Add more horsepower to the mix and you're asking for trouble. The cast piston is simply the weakest link. My dealer won't even replace a stock piston unless it's warranty work and even then they will ask if they can put the Wiseco in.

 

Mike, you make a good point about the ports being wider as well, though that would only be an issue if you're doing a pretty radical porting job. With the TB I'd reccommend just cleaning up the ports for better flow.

Hooking a port with a ring is nasty stuff though. I lost a cylinder once because the stupid retaining pin backed off, allowing the ring to tun, which allowed the end of the ring to hook the exhust port and made a real mess. The cylinder was nikasil lined, so there was nothing that could be done with it, though it was tore up so bad I doubt it could have been salvaged anyway.

I also noticed that you didn't mention clutching in your list of mods. How come? THat's the one thing I really like about Polaris' drive system.

 

I live in Sidney, Oh and I'll do your porting for you along with guilding you w/ your mods. Contact me at newdslover@yahoo.com.