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View Full Version : getting my 150 crossfire up to 40mph


Beefcake
07-24-2010, 08:15 PM
my tomberline crossfire 150 has great acceleration but the top end just isn't enough. I'm about to install a uni air filter, gut the exhaust and install a 130 main jet in the carb. I know this will get me a little more top end but I'm not expecting much. I've been checking out the heavier slider weights for the variator but I'm wondering if they are worth the trouble. I would like to do a 175cc big bore kit, but I don't really want to split the crankcase or atleast any time soon since I just installed new rings on my 150 set up. Is there any kind of internal gearing in the CVT I can change to get the extra mph's? I've been looking and can't seem to find any.

ckau
07-25-2010, 06:30 AM
There are several internal trans gear sets available ranging from a 13/40 [torque] to a 16/36 [speed]. These can be found on most of the scooter sites. http://www.scooterdomain.com/category_s/739.htm
Install is easy, a press is helpful but not necessary. Keep in mind scooters and buggys are two different worlds. what gives performance in a scooter might not work in the buggy due to the weight difference. You will do better gearing for torque internally and experiment with weights and external gearing for speed.

kliff
07-25-2010, 07:29 AM
Like ckau said, scooters and buggies are VERY different animals, if in only their operation.
For the most part, a buggy is on and off the throttle continually on trails.... the river bed at St Joe is an exception to the rule.
Most scooteristas pin the throttle and hold it, mile after mile, after mile, in the daily commute, or weekend pleasure ride. Gearing becomes a key to valve life, by keeping rpms under 7500. With gearing, and more importantly variator, a relatively stock (uni, exhaust, & jets) can pull a 250lb passenger at 57mph, at or about 7300-7500rpm. The guys that go for unlimitted CDI's and shot for hiway speeds without this driveline tuning, usually end up cruising at 8>9000rpm, mile after mile, and seldom more than 1>2K miles on the odo, before a valve spring gives up, and the top end is lost. My personal scoot runs out at 57mph/7400rpm, with 1500 clutch and torque springs, 115mm variatorand 14gr DRP sliders. But remember there is NO further reduction beyond the gearbox. The wheel mounts directly to the axle shaft, and is about 18" tall. It and I together only top out the scales at 475lbs, frontal area(wind resistance) could only be about 1/3 that of a buggy.

If you want top speed, the gears and sprockets are out there, but at what cost? My scooter is set up to be comfortable doing what I do, cruising at 45-50mph, with a little left on top, and a stock rev limitter in place.

My buggy will be set up for tight wooods, a cruise speed of 30-35, top end maybe 40, NON regulated CDI

Different worlds, different requirements. Build what you want, cross over if you wish, but remember 5 minutes of WOT, 8000rpm+ on a scooter, has done as much wear and tear on a set of valve springs, as probably a season in the woods with your buggy, even though it may have seen some 9000rpm+ "bursts" that never lasted more than a few seconds.

Buggies can get away with lighter variator weights, and non-regulated CDI's because of the area of operation, they are used in. Up and down on the throttle, 2000rpm> 9500rpm for a few seconds, back down to 4500, yadayadayada, that's what these things do best, and live the longest doing, as long as clean oil is in the sump, the valves are adjusted, jetting is spot on, and intake filtration is at a premium.

chuckorlando
07-25-2010, 06:22 PM
Agreed with both above. If you dont want to split the case you can go with a port and polish and a11 or so cam. This will give you more internal torque and allow you gear exrenaly for top end. Out side of engine work your basicly stuck with top or bottom and not much of both. I also agree with running these to hard for long shots. I had a fully maxed out gy6 till this week and It has run over a year with zero issues. Thats from staying on the valves, good oil, and knowing when to let out of the gas. If you know your motor you can almost hear the valves start to sing when you need to let out

SYCARMS
07-26-2010, 08:11 AM
Also agree, a good port and polish and cam. Where are you located? TOM

Beefcake
07-26-2010, 11:18 AM
I'm located in Wilmington, NC. Does your company SYC sell the cam I need? Anyone know of a good place for buggy P&P services? I guess I could check with my local machine shops.

chuckorlando
07-26-2010, 05:21 PM
SycPowersports or Tom is the guy who built my motor and can likely get you what you want

SYCARMS
07-26-2010, 05:41 PM
I do stock the cams and also do case boring and head porting. You can call me at 662-301-1563 if no answer just leave message and I will get back to you. TOM

EJ Mac
08-01-2010, 02:23 AM
I also agree with everyone. Speed is nice in an environment like the flats at St. Joes but the torque and trail running, hill climbing, and berm jumping are much more fun than running WOT. Those scenarios is one of the reasons I am finding it hard to decide whether or not to sell my Hammerhead it does great on the trails and berms (unless you don't commit when following ChuckO over a drop off from Hell) and will run well over 40 on demand. There is plenty you can do to liven that 150 up.

olderthan
08-01-2010, 09:57 AM
get tom to do a port and polish head for you
then decide if you need more