How can I get 30MPH out of an XC120? or faster

Drop it out of a airplane

Can't fit it in the cockpit of the Stearman with me.

I have it up to 15mph but thats still too slow for the young fella.

what mods have you done to the sled? I have done almost every mod available to my sons sled and its pretty quick. Next year I will be putting in one of my Kart motors in it. Its a Briggs Animal thats putting out about 16 hp.Depending on the mods you have done to it now a bigger motor might be an option for you as well.Contact REC. Motors they are very helpfull and have lots of go fast parts as well as drop in motors. The faster the sled gos the more you will have to look at stuff for the chassis, like carbides and studs...a shock in the back and a set of good shocks up front are a must if you want to be able to control it at higher speeds... rz

tow it behind a 340 or spend well over $1000.00 for a race motor. Way too much to spend when the lil guy is gonna outgrow the 120 in a couple of years. I've spent over 500.00 in making it go 22 mph (on radar)

my sons will go over 50, but that's with a 18 h.p. rec motor. we han't really found out how fast it will go yet. He gets a little scared when the rear end gets squirrley and we run outta room in the field by out house.

Gearing, clutching, Rec's valves and HD springs, exhaust. There are alot of things you can do and not spend alot of money. Are you looking for 30 on ice or in snow (deep or packed) makes a huge difference. There is also alot of friction in the drive train that can be fixed. Spin the track by hand and see if your drivers grab the track as it comes around. They actually hold the cogs of the track and slow it down. They can be ground down or remove and slide in on the shaft about a 1/16 and redrill. Clip every window, lots of little things can make MPH. I have one that will run 33 on radar on Ice, but only runs 24 in snow. Also ski's and placement is big on these little things. Hope this helps.

Indy, several ways to do it, but several things to consider. Theres many hot rod parts showing up for these sleds, many/most need someone well educated in small industrial engines to get the most out of. We build 120 engines for racing here in Wi and have been in the kart racing engine business for 20 + years. Several things you may want to consider. How much work can you do yourself? How important is keeping it trail reliable? We offer many parts for all of the 120 engines including cams and carbs that are abit further ahead then most of the stuff out their. A full built racing engine may not best fit you needs if just trail riding is the goal. As stated above replacing the engine with a larger engine may be the best and simplest answer. A Briggs Animal engine, about 10 HP on gas will bolt in without too much trouble, Cost around $500. and plenty of Hot Rod parts to make a reliable 25 HP from this engine, you will need a custom made pipe. Stock clutch will fit, there are many clutch options available that are far better then the stock ones. Gearing changes will also help.
Plan and research well and it can be done.
Bob Vehring
www.4cyclecentral.com

If you live in Canada you can go to Princess Auto and they sell the exact 120 honda motor that comes stock but its a 200cc made in china cheap motor that will bolt rite in for $120.00 and mod that. I now a guy who did that along with some other mods gearing, clutching,pipe, and just saw 38mph radar.

Do you mean that the whole motor is $120? Just bolt it in and the engine is tuned with the carbs and everything? Is this a faster/stronger engine worth the effort of putting it in? Meaning, enough of a performance gain? I am in Michigan (USA), will they ship to me if that is the price? Do you have a phone number or website for them? I would imagine that the 200cc motor would be all that we need for the yard and towing a plastic sled behind it. And then I wouldn't have to start changing gears and clutch to keep up with my growing boys! I would put better skis and carbides and studs on it. Also have been reading about putting a shock on the rear suspension. Anyone know what shocks would work on the skis for cheap?

Google Princess Auto and it should come up. I do believe the motor is complete!! I am sure you will need to do alittle tuning as well but a 80cc gain should be a good start.

E-mailed them and they say they don't have a 2.0 Honda motor and they don't ship to USA.
Anyone know where else to get a bigger motor that will just bolt in on the cheap?

I put the Honda rep 200cc $140 engine in the boys xc120. 6.5 hp then I by-passed governor to make ???hp. Sled flys with me on it and 12/28 gearing.

If you have a Ski-Doo mini, it drops in no problem- turn key, many have done so. It was a hassle to make fit and I don't recommend it for the Polaris. Techumsi (sp) make a stand up motor that is a direct replacement for fit and is 6.5 hp, saw it on sale for under $200.

There has to be a PricessAuto type store in USA selling this stuff. I went in there yesterday and picked up a new Comet clutch for the sled and a 12 tooth gear for it for less than $40 taxes in.

Not sure what top speed is as 120 speedo doesn't work. LOL

These engines are showing up in the kart racing world, be very careful, they claim to be a copy of the Honda, but as you see from the price, the materials used and the quality of work is very cheap, there have been numerous reports of the flywheel and its magnet coming apart, some as low as 4000 RPM. The damage from this, is or could be very severe, including possible injury. This is a serious issue in our sport. These are available at any place like Northern or Tractor supply as well as parts houses. Think very seriously about what you buy before putting your child, or anyone near by, at risk. A blown flywheel can kill you. Bob

That's interesting and good info. I was told that the GX series of Honda engines were made in China unlike most of their engines. These Chinese copies of the GX look the exact same but I expect they are a cheaper knock off at that price. The flywheel has a metal cover over it and I will inspect it and add something extra to ours just in case.

Bob

Many manufacturers now have parts ( or engines ) made in China, China is certainly capable of producing quality parts, if the price is paid for quality parts. Many other company's there make very cheap parts or again engines. There are as far as I know, many, ( over 50) companys making cloan engines that do look just like a Honda but the material used and the quality of parts is far below Hondas standard.
I'm not here to knock anyones product, but there are documented case in the kart world of the flywheels exploding, usually after the magnet which is glued in place and has only one screw holding it comes loose. Sometimes at no more then 4000 rpm. There are companys that make billet flywheels for the Honda engines. The stock steel cover will not contain the parts if the unfortunate happens. You could also look into substituting the Honda flywheel but I am not sure of how well it fits. Bob

The briggs animal is an awesome motor especially for the money. I had one in a cart and they make good power stock and have unlimited potential fairly cheap. We had one built with a dyno sheet of 19hp on pump gas. Better yet, for about a grand you can put in a briggs world motor.... I saw a 120 polaris with a hot animal and it was real fast.. I mean real fast probably close to 45-50. You should change the track drivers though because it was ripping the drive lugs off.

Animals are a very good choice and cheap for what you get, 10 HP to mid 20's. and much more reliable at that HP level. Goodwin has drivers that drive through the windows to solve the track problems with big HP.
Bob Vehring
www.4cyclecentral.com