200cc ATV Jetting

Haqerzmer · 07-12-2010, 09:21 PM

Hi to all!

I just bought a 2009 200cc ATV, model is West Coast TrailBlazer, anyway, chinese made. The setup is very similar to the 200cc GIO Beast. I bet they are identical, i guess just "branded" by different companies. Anyway, after putting it together (loctite everything baby), changing the oil to a 15w40, started it right up no problem, but like everyone else, the atv idles very poorly. I actually have to loosen (almost completely off) the mixture screw just to have it idle. Every forum that I read seems to recommend that I get the mikuni carb for a 250cc (pz30) as an upgrade to make it better. I agree, but my question, do I really need to buy the new carb? how about just jetting the stock carb? Obviously I have to make the pilot jet bigger, and probably the main jet too. Well, even when I buy the mikuni carb upgrade, some members here still re-jet the carb with 110 main / 25 pilot. I can't seem to find a thread where as they kept the stock carb, but just re-jet it to make it run like a pro!

TurboT · 07-13-2010, 12:47 AM

Quote:

Originally Posted by Haqerzmer

Hi to all!

I just bought a 2009 200cc ATV, model is West Coast TrailBlazer, anyway, chinese made. The setup is very similar to the 200cc GIO Beast. I bet they are identical, i guess just "branded" by different companies. Anyway, after putting it together (loctite everything baby), changing the oil to a 15w40, started it right up no problem, but like everyone else, the atv idles very poorly. I actually have to loosen (almost completely off) the mixture screw just to have it idle. Every forum that I read seems to recommend that I get the mikuni carb for a 250cc (pz30) as an upgrade to make it better. I agree, but my question, do I really need to buy the new carb? how about just jetting the stock carb? Obviously I have to make the pilot jet bigger, and probably the main jet too. Well, even when I buy the mikuni carb upgrade, some members here still re-jet the carb with 110 main / 25 pilot. I can't seem to find a thread where as they kept the stock carb, but just re-jet it to make it run like a pro!

There's nothing to say you couldn't try it if the stock carb uses the same jets the mikuni uses.

I would break it in some first though with a few tanks of gas and a fresh oil change before you get too worried about how it runs on the first day.

Forum member W&G has a stock carb in his Beast and it runs like a champ with no jetting done to it. Just a lot of fiddling to get it just right over time.

Weldangrind · 07-13-2010, 12:04 PM

I've had so many carbs apart lately that I can't remember for sure, but I don't think I rejetted my stock Beast carb.

The stock carb will perform nicely, but it's a bear to start and warm up. Also, TurboT's quad pulls him uphill faster than I can go (and he's a giant). I have a Mikuni to install, it's only a matter of time. I also have a Monster muffler for it.

I'm sure that you could remove the jets and take them into a local bike shop to match them up. I can't recall if they're the same as the Mikuni, but probably. I got mine at Clearbrook Yamaha in Abbotsford (really good guys there).

I believe that the Mikuni is a better quality carb. I think that the casting and design is superior to the stocker. If you can get a Mikuni cheap at www.giobikes.com , then why not?

TYE · 07-15-2010, 09:33 PM

i got a pz30 mikuni but rejetted with a 22.5 main and a 110 needle and it runs awesome. Jets are so cheep you could try your stock carb but a larger air intake makes a big difference. good luck

waynev · 07-15-2010, 10:16 PM

Quote:

Originally Posted by TYE

i got a pz30 mikuni but rejetted with a 22.5 main and a 110 needle and it runs awesome. Jets are so cheep you could try your stock carb but a larger air intake makes a big difference. good luck

22.5 pilot jet and 110 main jet, right tye?.

TYE · 07-15-2010, 11:56 PM

right, needle? anyways this set up is great i finally finished my rewire and all is now good.ill try to post a vid soon

waynev · 07-16-2010, 10:33 AM

I'm running pretty much the same as tye, i have the Mikuni PZ30, performance CDI, NGK DR8ES-L plug, beast performance exhaust with the muffler subbed out for the Monster muffler and a UNI air filter, with this setup i had to goto a 25 pilot, 110 main, jet needle is on the 4th groove down, and A/F screw is about 1-1/4 turns out, this has worked great for me, easy starts and great power.

07-12-2010, 09:21 PM	#1
Haqerzmer Join Date: Jul 2010 Location: Surrey, BC CANADA Posts: 1	200cc ATV Jetting Hi to all! I just bought a 2009 200cc ATV, model is West Coast TrailBlazer, anyway, chinese made. The setup is very similar to the 200cc GIO Beast. I bet they are identical, i guess just "branded" by different companies. Anyway, after putting it together (loctite everything baby), changing the oil to a 15w40, started it right up no problem, but like everyone else, the atv idles very poorly. I actually have to loosen (almost completely off) the mixture screw just to have it idle. Every forum that I read seems to recommend that I get the mikuni carb for a 250cc (pz30) as an upgrade to make it better. I agree, but my question, do I really need to buy the new carb? how about just jetting the stock carb? Obviously I have to make the pilot jet bigger, and probably the main jet too. Well, even when I buy the mikuni carb upgrade, some members here still re-jet the carb with 110 main / 25 pilot. I can't seem to find a thread where as they kept the stock carb, but just re-jet it to make it run like a pro!
	0

07-13-2010, 12:04 PM	#3
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	I've had so many carbs apart lately that I can't remember for sure, but I don't think I rejetted my stock Beast carb. The stock carb will perform nicely, but it's a bear to start and warm up. Also, TurboT's quad pulls him uphill faster than I can go (and he's a giant). I have a Mikuni to install, it's only a matter of time. I also have a Monster muffler for it. I'm sure that you could remove the jets and take them into a local bike shop to match them up. I can't recall if they're the same as the Mikuni, but probably. I got mine at Clearbrook Yamaha in Abbotsford (really good guys there). I believe that the Mikuni is a better quality carb. I think that the casting and design is superior to the stocker. If you can get a Mikuni cheap at www.giobikes.com , then why not? __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

07-15-2010, 09:33 PM	#4
TYE Join Date: May 2010 Location: waterdown Posts: 90	i got a pz30 mikuni but rejetted with a 22.5 main and a 110 needle and it runs awesome. Jets are so cheep you could try your stock carb but a larger air intake makes a big difference. good luck
	0

07-15-2010, 11:56 PM	#6
TYE Join Date: May 2010 Location: waterdown Posts: 90	right, needle? anyways this set up is great i finally finished my rewire and all is now good.ill try to post a vid soon
	0

07-16-2010, 10:33 AM	#7
waynev Join Date: Aug 2009 Location: London, Ontario Posts: 1,097	I'm running pretty much the same as tye, i have the Mikuni PZ30, performance CDI, NGK DR8ES-L plug, beast performance exhaust with the muffler subbed out for the Monster muffler and a UNI air filter, with this setup i had to goto a 25 pilot, 110 main, jet needle is on the 4th groove down, and A/F screw is about 1-1/4 turns out, this has worked great for me, easy starts and great power.
	0