[John parker]

I have run a k9C cylinder with a BB insert in the head, the squish was tight .73mm I ran 2 base gaskets to get it to .82. The combustion chamber was 10.7cc. Great snap out of corners, good for shorter tracks but runs out of topend on longer straights. I do have to run a 50/50 C14 to pump gas mix, but I did run 20 litres of VP’s MRX02 to see how it goes,  wow, big power gains! My only fear in running a tighter squish is the rod streching during over rev and smacking the head. I put on just over 10 hours before doing the topend and have 16 hours on the bottom end, which is in need of doing now and have had no problems.

[John parker]

I cracked a cylinder on my K9C, I sent it off to Millenium with a new piston. They welded it, renicked it for $190 and worked amazing all year.

[John parker]

Thanks everyone for the help. I hope to see you guys out there September.

[John parker]

Hi everyone, I am somewhat new to karting but not to racing. I am interested in coming to the event at the Ridge on September 30. My friend and I would like to know what’s required for us to race, aside from the karts and gear. Do we need to pre register, if so home much. We have two ICC shifter kart and all the nesassary gear. Any information would greatly appreciated. Thanks.

[John parker]

[quote quote=58935]Good to see you are getting some track time. If you are talking about Vinny and Lorenzo Mandarino, yes they are great guys. If you know anyone looking for another ICC kart, I just happen to have a VERY nice one sitting in my garage. :-)) [/quote]

Yes I may know of someone. I will pm you.

[John parker]

[quote quote=58809]Hi John You have 2 options in the lower mainland. There is a track in Chilliwack http://www.westcoastkartclub.ca, and Italian Motors track just across the border at Sumas http://www.simaracing.com. The second option is the only track where they run the ICC engines. [/quote]

Thanks Steen. I am a member at Kart BC but not racing, we have rented a container at the track for storage and wrenching. During last summer I was going out too the track practicing 2-3 times a week with a friend, who like me also bought a shifter kart. We both new very little about the the sport, but got a lot of help from the owner of Vemme kart, super guy. We spent most of the Summer understanding driving, kart setup, motor tuning. We both concluded that we are going to race this year, probably both TAG and shifters baring and political problems. What we would also like is to run our shifter karts at a few road courses such as Laguna, ORP, The ridge. I come from a motorcycle back ground and have raced at these tracks and others through out the US and would love to try it in the Karts. So I am trying to find out if it is possible, and if not possible to race, then just to practice.

I have been down to Sima and seen there setup, it’s nice but a little pricey for what it is. We are going to run a practice day and race there this spring so may be we will change our minds.

[John parker]

Ok I now get what you are taking about, we were still not on the same page till now. When I was talking 125two strokes, I was comparing the cost of running a 250 four strokes to the 125 two strokes, not 450 four strokes. So if I understand you correctly you are running 450 not 250 four strokes? If that is the case then yes the cost would be lower than a 250f, because the motor is not being run as nearly as hard. So your not running against 125 strokes then? Again my ignorance of this sport is showing, but I have been following the European series which seem to be dominated by KZ and have herd little on 4 strokes except for a Swiss made 250 four stroke that was super expensive.

My 450 I ran in SM did require head work at the end of the season that was around the $500 plus a piston $450, not much considering the abuse but it was purpose built, Falicon Super crank, yo yo dyne clutch, 13.5/1 piston, bla bla bla head work.  But by the end of the second season it was a lot more expensive. So again if you are running on the same tracks as the 125 karts yes the 450 motors will last longer, but when they do go, and they will go, it’s going to be more money than a 2 stroke.

What are the difference with the new KZ that make it that much better than the K9c? I have checked the port timing, combustion chamber, Squish, even the piston I haven’t seen anything I would consider ground breaking the one thing I did see was the intake track and reed cage but really that would be minimal. Am I missing something?

[John parker]

Granted the European motors are way over priced for what they are, but used ones aren’t that bad in price. I have found 2 TM,K9C for $2500 Canadian this is cheap Considering there over all design isn’t that out dated to current models. New top AND bottom end replacements are no more that $1000 C, which would be a full crank rebuild, rod, piston&rings, bearings, seals reNik cylinder (if needed), me doing the work, Cheap!

Rebuild my YzF250 motor top end, $400 just in valves, not including guides, springs, seals, retainers or machine work that maybe required. Realistically $1000 is what your looking at for a full rebuild. This is just to head, I still haven’t touched the borrow end yet, no labour with that price iether. MotoX teams operating cost went through the roof with introduction of 4 strokes purely on motor costs! I have rebuilt so many of both 2 and 4 strokes, there is no comparison to cost, the amount of parts alone used in a 4 stroke tells you there not cheaper.

Just as an added note: I ran an AMA road-race team for 2 full season so I know the cost related to racing. Two riders, 4 bikes all 600s so is fully awear of costs related to racing and motors.

[John parker]

What we have here is a communication issue not tech issues. I was under the impression, given the title of the thread (4 stroke shifter karts) that you, Chris were talking about 250 four stroke motors for karting not 2 stroke, big difference. So with that note I agree with you. My issues was referring to running a 125 smoker to a 250 four stroke.

[John parker]

Hey Chris, your experience and mine is vastly different in both cost and time on both 4strokes and 2strokes. I have to change my top end on my YZ250 at least once a season, I am unsure of how much you ride or how hard

Admittedly my Karting experience is limited but my mechanical experience isn’t. I have an Italkart (shifter) with a K9c motor. I replace my top end after 30 litres or roughly 3 hours. That process takes about an hour going slow, cost me 125$ (no wrist pin cage) in parts and I am back in the game, pretty cheap. Bottom end after 70 litres or 12+ hours, 300$ and 5 hours of work, again cheap. I guarantee a 4 stroke won’t be nearly that cheap in both time and parts.

As for my CRF 450s, one is SM with a purpose built motor ($5,000 in motor work, yea it’s a grenade,haha) the other is MotoX only with motor work of just a cam and minor head work, pipe and tuning. Run too hot on the stock Honda motors and kiss those shit TI valves good bye, recut the seats and new valves $300 plus time and on 4 stokes it takes WAY more time to do work. After 60 plus hours, bottom end and top end. Piston$350+ bottom end package from hot rods$600, if you need reNik the cylinder ad another $300 we haven’t even talked about the valve train yet. Now on all my YZ250F i have owned I check the valves 3-4 times a season, with at least on adjustment, (more time wrenching). By the end of the season I need a total top end (valves) freshen up valves, maybe be recut the seats, depends. New Crank and bottom end, and have gone through 2 Pistons. All of these are basic needs required to prevent a catastrophic motor failure, and this is at MotoX where we don’t sustaine long periods of high RPM. If I was to run these motors like they would be run in karting it would be safe to say your maintenance  would be double that, and remember I do all my own work, factor is someone who has to pay for labour and I thinking, “stick with the 2 strokes” ).

[John parker]

Hi all, I am new on here and new to karting and I have been following this thread, it’s interesting. I come from a moto background and I can tell you straight up, 4 strokes cost bucks! If you think maintains 2strokes is bad wait till you have to do a rebuild on those. I have 2 crf 450’s and a YZ250F and a YZ 250 two stroke. All of my 4strokes are for sale, it’s just too much time and cost to justify it, and I do all my own wrenching. They have one good point, torque, that where it starts and ends. For moto it helps for sure, they can mask  your lack of skills, unlike a 2 stroke. One other thing to remember is in moto they aren’t wide open as much as they would be on a kart so valve adjustment time would be more frequent. Also the different manufacturers use different quality TI (Honda cheap, Yamaha expensive)in there valves so depending on the manufacturer valves may not last as long, like Yamaha. My opinion, leave karts with 2 strokes.

[John parker]

[quote quote=57655]http://www.kartbook.net/forum/topics/the-ryger-2-stroke-engine This will be the future if it honestly exists. [/quote]

I am pretty sure this doesn’t exist. It has in the spec 54.2 mm stroke. Well at 17,000 rpm the piston speed would be in excess of 6000fpm, WAY above an an acceptable reliable design. The rods wouldn’t be the issue, Honda built its oval piston motor back in the 80’s that spun well over 30,000 rpm the rods weren’t a problem. The piston speed is the real issue with the deign. Yea that motor in the above link, given the specs is a pipe dream.

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