New 4 Stoke Class for 2009

I finally found time to get stuck into my HF motor today and popped out the governor, etc. I have a few of questions.

- What are you guys doing for a throttle cable hookup ? The guy on the video had some little fabricated brackets. I'm looking for an off the shelf solution as I'm lazy and can't be bothered to fabricate my own. Todd, do you have a solution ?

- Gas tank. Are we going to run the stock tank or ditch that and use the proper on chassis tank ? That cap on the stock tank looks like it will leak like mad once the fuel starts sloshing around.

- Air filter. Stock or something better ?

- Exhaust (as above)

- Dan , where did you get that cool clutch/chain guard ?

- I see Dan's motor has a cool exhaust and a different carb. Will our rules allow those kinds of mods ? (Just wanted to check before I buy any go faster parts that will not be allowed)

- What happens when you store one of these karts stood upright on it's tail ? Does all the oil fall out the breather on the cam cover ?

Simon.

PS That video made me laugh every time he mentioned the 'blower cover'. I'm more of a turbo kind of guy myself, but a blower on a kart would still be cool ;-)

Hi Simon,
I bought the "Chain Guard Plus" for my kart, it's supposed to keep the block from twisting, I don't really think that is going to be a problem with Box Stock, but it also raises the motor on the mount and I did need that. It's about 3x the cost of the other chain guards, I wouldn't buy one again unless it's for a modified motor. From what I understand, any 4 stroke chain guard will work on the clone, mine was from a Briggs Animal. Here's the link:
http://www.fastermotors.net/Chainguard.html
The stock exhaust might be a challenge, I know on my kart it's going to be blowing hot exhaust right by my arm. If you read the clone forum, the guys in the South get burned pretty regularly by the Exhaust, that does not sound to fun to me.

I found a guy in the South that will build pipes for us with muffler mount for $35 each, maybe less if we do a group buy of 10 or more. I posted some pics of one without a muffler mounted to an engine and one with a muffler by itself at the bottom of this post. Also on my kart I have some issues with clearance with the stock muffler. My personal feeling is that we should allow aftermarket pipes and filters to let the motors breathe a little better and prevent burns, plus they just sound cooler with a pipe! Here’s a link to another pipes that’s even cheaper that Karl found, check out the heat shield, I would prefer to buy a pipe that give performance over a shield to prevent burns!, but maybe that’s just me!
http://www.geckermotorsports.com/BoxStock.htm

There is another set of rules that may be as popular or maybe even more popular then the BSP rules, you can read them here, thanks to Jason for that! I personally like these rules better then the BSP, but I will go along with what the majority wants. If we do go with aftermarket pipes, I think we should spec them and maybe the club could do a large buy and we can buy them from the club?
http://www.thunderhill-speedway.com/Blue%20OHV%20engine%20rules.html

Gas tanks mounted on top of the motor has never seemed like a good idea to me. When we brought in the Honda GX120 into quarter midgets, we had a rule the tank had to be mounted in back of the seat. That was fine in quarter midgets, the tank was higher then the motor and could be gravity fed. Clone carbs are not pumper carbs like we are use to in 2 strokes, if we do mount the tank under the steering column we would need to have an external fuel pump. They cost $20-$30 and both Walbro and Mikuni make them. I don’t know if there is any performance advantage to that, maybe someone else could comment. If there is not, maybe we could leave that as a non tech item. I do think we should leave the stock carb on there, some rules allow the jet to be reamed out, I’m not sure on that one, I guess that’s why we need to test these motors and the sooner the better IMO.

Not sure about what happens when you stand them on there end, but another thing we will have to address is the need for a catch can from the breather port on the vave cover. It’s one thing on a dirt track to spill a little oil, I don’t think we would be very popular with the rest of the club if we oiled down the track every time we ran! That’s a pretty simple fix that can be as simple as soda can with a hose going from the valve cover to it held on with zip ties.

Maybe I should set up a poll about the pipe and tank on here?

Ooops, I almost forgot the pics!

Most tracks running clones started out using the original BSP/FKA rules and then tweeked on them either in the interest of safety or local racers interest. Dan's suggestions are sound ones and they all address the very same safety concerns that I have. Obviously we are not alone as Jimmy Sims (BSP/FKA) annouced some of the rule changes over the weekend (see rules update below). Pipes should be no problem as they are already being made to spec by a couple of different mfg. Here is just one example; http://www.geckermotorsports.com/shop/details.asp?prodid=CP-750&cat=524&path=524
Addition of a fuel pump is inexpensive and easy install as it is a simple hoses to carb setup (no pumparound or return to fuel tank). I'd like to use an after market air filter for the simplicity (stock air box is a PITA to work around) and racier look. Personally I like the rule changes as outlined below. What do you guys think?

WKA has not made a new class for clones and has not set any rules. What they have done, is approve Conditional Use Of Non-Karting Engines In Local Option Classes (07.17.2008) See link here at: http://www.worldkarting.com/pg/news/2008-07/clonemotor.html

This is important because we run under WKA insurance on racedays!

After the anouncement was made in mid July there was a lot of controversy from WKA tracks concerning the mandated SFI approved flywheel for engines spinning over 4,500 RPM. After the WKA announcement Tom Cole of ARC Racing had testing performed on a stock flywheel where one was spun up to 11,000+ RPM before any problems were encountered. Now Tom could have just laid back and sold a bunch of flywheels but instead he supplied the parts and paid for the test to prove the stock flywheel was ok for box stock racing!

See following links:
http://karting.4cycle.com/showthread.php?t=203981&page=1&pp=30
http://karting.4cycle.com/attachment.php?attachmentid=2286
http://karting.4cycle.com/attachment.php?attachmentid=2287

After the results of the flywheel testing it was reported that WKA sent out postcards to all of ther sanctioned tracks concerning flywheels. Tom receive a post card from WKA marked Jul 30 2008 stating;

The ARC or stock flywheel may be used in the unaltered BOX STOCK Clone engine at this time. Additional updates will follow based on further testing and evaluation.

Lets hear some comments on what you folks think about the new changes to the BPS rules. Or we can put it to a vote as Dan suggested.

~Karl
Karlznet@aol.com


______________________________________________________________________


BPS/FKA RULES UPDATE

There are a few changes to the Box Stock class that Jimmy Sims is going to announce at the next FKA race this Labor Day weekend that will be implemented in the next few weeks. These changes are based upon racer's experiences with the engine with respect to safety, comfort, and reliability and are also intended to make a necessary change in the appearance of the engine so it does not so closely resemble the Honda.

You may make these changes and run them legally anytime after 9/1/08.

1 . The fuel tank will be removed from the engine and will be replaced with a remote floor-pan mounted fuel tank and a pulse-style fuel pump. The pump may be pulsed from either the crankcase, or the rocker cover as seen here
You MUST change to the floor pan mounted tank before the first race of the KOC series, which is 9/20/08.

The rest of the changes must be done before 1/1/09, but may be done anytime after 9/1/08.

2. Carb Main Jet will become non-tech

3. An Air Filter adapter of 1.375" max length and pod-style air filter (like what we use on flatheads) will be allowed. ARC #6931, AGK #AGK100 and Pulse Racing's "cup" style are all legal air filter adapters, or, you may make your own.

4. A spec. muffled header pipe will be allowed. The pipe, excluding a small flange for muffler attachment, must be single stage, 3/4" O.D. steel. The entire length of the header including the muffler must be no more than 14". The muffler must be one of the following or a duplicate:
Briggs #89966
Arnold (by MTD) #—105 (can be found at Lowes and Tractor Supply, etc)
Rotary #11270, or #1270 (same as Arnold) OR #12294, or #2294 (same as Briggs)
Muffler attachment is non-tech, but the complete muffler must remain attached and intact.
The header pipe is to be wrapped up to the fat part of the muffler.

The pipe we are using is based upon the design by Dan Lemke at Pulse Racing, but may be made by anyone. I have them in stock now at ARC. You can also get them from PEC, Gecker, Dan Lemke and others.

I also like the Gecker pipe and will be ordering a couple soon, but I feel the pipe choice should be left open. With the new spec being round tube 3/4" od, lawnmower muffler, and a 14" overall max length, your not going to see an advantage from one mfg to another. I think this spec was made for a few reasons; so the backyard mechanic could hack up old lawn furniture and weld up a pipe with a 5 dollar muffler from home depot (don't laugh it's being done), so there is no big HP/RPM gain over stock muff, but mainly to keep the more expensive RLV combo or any other manufacturer from becoming the sole spec pipe supplier.

The stock fuel tank has been an on going issue with southern and midwestern racers since the start of Clone Racing. The main reason for doing away with the stock tank is safety, plain and simple. Leaking caps, petcocks and split seams have seen most folks switch to OEM Honda tanks at roughly the same cost as a buying a fuel pump, hose and a barbed fitting for a pulse line. In addition the location of the tank makes for very awkward driving for us shorter drivers (you'll see what I mean when you get yours mounted up).

The stock air filter is very good design and likely to flow as much air as an aftermarket, it just seems to be a pain to work around. True, the spec pipe/aftermarket filter combo may change the HP/Torque curve slightly but gearing properly to utilize avalible torque is going to be key here. Over-reving with the stock exhaust/filter only makes more noise leading to more frequent valve spring replacement. Stock valve springs are cheap (5 bucks?), Finding someone with strong thumbs to help change them is going to be the biggest challenge.

~Karl

Dan Chase wrote:
Maybe I should set up a poll about the pipe and tank on here?

Yes, we should figure out what everyone wants to do as the choice of pipe has an impact on what chainguard/heat guard will fit best.

Stock tank vs on chassis tank probably isn't so critical to nail down. Maybe we can leave that as a free choice ? I did notice in the 4-cycle Stock Box Project forum that one of the clubs in the south east were mandating the use of the chassis mounted fuel tank.

If we are voting I would vote for a spec exhaust/muffler and free choice on gas tank.

Simon.

I gave my friend "Tommy Bondo" an old Emmick? basket case to put the Honda GX200 he built on.

Once he caught wind of the clone revolution he scraped the Honda and got a clone engine.

Tommy, being an "outside the box" kinda guy, found himself an e-start clone engine.

Below is a shot of the Box Stock Clone "TAG" he is putting together.

why you funning me like that Karl, could have at least let me scrape the rust off her and put the spindles on the right side before posting a picture! just kidding, just to hot last few days to get motivated, she'll look better by sunday, and yes I'm cleaning the bench

I wonder if this is what they meant in Star Wars when they talked about the Clone Wars???

Jason, how does the tank location work out with Thomas' arm? It sure looks like the seat is a lot easier to mount!

Tom, I love your TaG clone!

The tank does not seem to be a problem with the arm on the cadet kart, but I don't feel good about those cheap tanks full of gas on top of a hot engine! I believe the tanks can be removed and a pump put in for the tank between the legs. This has no performance value and is safer in my opinion!
Eventually this will have a full set of guards and heat shields. Clutch, exhaust, rotor guard, and so on. It will probably be one of the Club karts. Safety first!


One of the things that I am not sure about the fit on the full size karts is that kwik-link. It is awful close to the upper thigh when you sit down! Could be possibly painful! I am looking into another throttle linkage now.

Neil You are good to go!!! I will give your motor to Melanie or another Kinsmen member at the Reno IKF.

No Neil only $7.70 for NV sales tax...

Jason,
The clutch should be mounted with the sprocket against the engine.

If the clutch is turned around, the chain hits the engine mount.

Yea, I'm noticing the same problem, running it to the outside seems to cure a few clearance issues

Something is not right if the chain touches the engine mount. The base looks too far inboard or is too wide. It should just barely overhang the frame tubes. (International spacing mount on and American spacing frame?). Your motor is mounted well outboard on the base. On both of my karts the motor is slightly inboard (1 emmick, 1 margay). I'll try to take some pictures tonight.

Of course it doesn't matter to the motor or clutch whether inboard or outboard. But you might struggle to find a chain guard wide enough.

The one above is a cadet kart. I have a guard wide enough to install on it. The mount is from BMI. It may or may not be the perfect one, but the price is right. After all this is a budget based class.
I have a 98 Energy frame I currently run a KT100 on, I have room between the seat and unico style pod to set the engine in with no clearance issues, not even moving my seat. I might be able to run the clutch the other way with no issues. Most of the people the are putting these together have old chassis that have been hanging in the garage for a while. The engines are offset so much to keep from moving the seat over too much. The other issue might be that those who have a newer chassis (with a 3rd bearing on the axle) will have clearance issues with the sprocket carrier not being able to line up with the clutch if it run the other way.

Each kart will be set up differently unless you find someone who is running the same chassis.

Lets post what chassis you are building so if there is someone with the same one there is some feedback on mounting, or set-up problems.

I will be using a Energy chassis with only 2 axle bearings.

Karl and I are also setting up a Emmick cadet(old style, spindle bearings in the frame not the spindle), and Emmick full size(old style, spindle bearings in the frame not the spindle)

What is everyone else building?

I've uploaded pics to my photo gallery of my two karts. (They will need to be approved by the administrator before you can see them.)

The orange/yellow mount is my F200 kart. It's a current style Burris 15 degree mount. The chassis is a Margay 4.6 with international spacing. The silver mount is on the kid's kart. It's an older style Burris 15 degree mount. I bought it used for $40 delivered from the 4-cycle forum classifieds - a great resource for racers on a budget. The chassis is an adult-sized Emmick with American spacing.

Looks like the BMI mount is universal so there is extra width when used on a chassis with American spacing (e.g. EmmicK). I've never seen the BMI mount up close but it looks like the motor plate is separate from the legs and clamps. And it appears that one side registers to the frame while the other floats to allow for the two spacing options. Are you able to rotate the legs and clamps 180 so that they register to the inboard tube? This would put the extra width away from the chain.