I am new to Karting and looking at buying a used 2014 Tony Kart roller that was set up for TAG and I’d like to convert it to 4 stroke, I understand a Motor mount will be needed and the sprocket location moved (probably other things too) and I’m looking for guidance on the process (can this be done at all for starters without chassis mods, cutting/welding).
I can’t answer the other question (re: '14 Tony Kart), but the answer to this question is a resounding “ehhh…”.
I’ve done it a couple times on a couple chassis, and sometimes it can be done but sub-optimally so. For instance, I cannot run the full gamut of ride heights for my daughter’s kart because the chain hits the crossmember at high ride heights. She is also constrained to run a 35-pitch chain and spec tooth counts, so I could avoid this with a 219 (smaller gears for the same tooth count).
For both hers and my old Praga, I was limited in my options for engine placement and seat position. Both had a narrow window where everything would fit, and my FS4 has a broader window. So it was doable but forced my hand for some other options like clutch inboard/outboard.
Some chassis are easier than others, but a 4cycle will easily fit on a 2014 otk. Some chassis do get tight on the rear crossmember but with mini gears that can be solved also.
1 Like
Make sure you have an axle that is setup for a 4 cycle.
What 4 cycle engine are you gonna use. For a 206/WF, all you need is 4 cycle engine mount and shifter rear axle. You can also have a machine shop to cut you current TAG axle with shifter/4cycle keyway location. Depends on how big your seat is, you can potentially bend your right side seat struct for extra room to run the clutch inboard.
The only changes that MUST be done are to run a shifter axle and 4-stroke motor mount. Typically people run an inclined motor mount like the Odenthal 8 degree. This mitigates the chain to cross-member clearance for most karts and gets the intake filter up and clear of the rear tire.
The only other challenge encountered is the left to right clearance for everything. On some chassis it can be tough to mount the motor where it clears the seat and the chain clears the seat post and the sprocket clears the middle/3rd bearing carrier bracket. Some people hang the motor off to the right quite a bit to make it all work out. We always bent the left side seat strut out a bit and shifted the seat full left and ran some spacer on the right side, then we ran the clutch with the driver facing the motor (inboard clutch) and the motor shifted inboard as much as the seat and seat post clearance would allow. This helps balance the kart a little more L to R.
Hi David,
I’m yet to see a two-stroke chassis that has been modified to take a 4 stroke like Briggs or GX200 clone.
Just ensure the engine mount has a good offset. I use one of these on the 2012 CRG. With the 17t clutch sprocket inboard the #219 chain misses the seat stay by a clear margin. Not close to rubbing on any part of the frame.
As Michael said above, make sure you have an axle with the inboard keyway present.
This is a pretty easy modification. Countless races have Ben won with 4 stroke engines on 2 stroke chassis.
I have drilled holes and used a shorter key to mount the sprocket inboard. It is not a big deal. Use a calliper to mark the Center to Center distance for your axle key.
The engine mount shown above will give you plenty of adjustment side to side.
1 Like
Thanks for all the input, seems pretty straightforward, I have a Mill, Lathe, Tig/Mig setups so I think it wouldn’t be too bad with what I’ve read here. I may get to look at/drive a complete Kart package this weekend at a local Kart track. Waiting for pictures/details but it may eliminate the conversion process, (they allegedly have a ready to run Kart (Briggs L206) that has a rock hit tube, track guy says fully functional/structurally sound in my price range so wish me luck…
1 Like
As you have surmised it can be done and is fairly common. While there are chassis specific for 4 strokes, it is usually more about different frame diameter tubes and eliminating the middle bearing support bracket.
I would add a few things. There are a lot of choices for motor mounts but the Odenthal as others are recommending is both very adjustable and strong. Two things that will be important. If you are a bigger guy things get tricky with fitting a seat and a motor. It will become a compromise for both seat and motor location. I don’t know if all clutches allow for inboard or outboard location of the driver, but getting one such as the Hilliard that does allow for this will give you more flexibility to line up everything.
On the complete kart you are looking at…What do they mean by a “rock hit”? If it is a bent frame member I would be a little skeptical.
I’m also trying to install a 4 stroke on a Cadet chassis.
Where can I purchase a 30mm axle that’s keyed for both 2 stroke AND 4 stroke?
Google “30mm kart axle 2 stroke and 4 stroke” and pick your poison. Quite a few options pop up
I believe all PKT axles are dual keyed. The 3.0 is a great 206 axle in most karts.
We dual key our factory OTK axles if you are interested in a factory OTK axle.