[Walt Gifford]

Same problem here.

Gif

[Walt Gifford]

https://www.google.com/search?q=kt100+throttle+cable&source=lnms&tbm=isch&sa=X&ei=kfrqUovtJ_OpsQTi9ICwDw&ved=0CAkQ_AUoAw&biw=734&bih=439

[Walt Gifford]

You want the cable to extend up and out to the right in a big loop and then turn under the airbox and go straight to the pedal. You don’t want any hard turns or friction. also, you should have some kind of return spring on the pedal, don’t depend on the carb spring alone. At the engine end is the cable housing held firm with a brass fitting or does it just slide into a small cup? If it’s a loose cup you need to put a piece of fuel tubing over it to keep it straight at the joint.
The cable length is also critical, too short and the carb will hang open.

Gif

[Walt Gifford]

Just get Bridgestone “YLC” compound tires. Run them at 12 PSI.

http://www.cometkartsales.com/store/tires/bridgest.htm

Gif

[Walt Gifford]

Hello Steven Hahn, I would be curious to find out about any safety training track workers receive that might prevent them from driving golf carts across the racing line and parking golf carts in run off areas during pro kart practice sessions.

Thanks,
Gif

[Walt Gifford]

Some sprocket mounts are double sided. Make sure the flat side is on the inside. Do you have the sprocket on the inside of the sprocket mount with the heads of the bolts to the inside? The heads of the Axle bearing bolts should be to the outside.

Gif

[Walt Gifford]

Kirt, are these 40mm bearings? If so get new ones with rubber seals and you’ll never have that problem again. Shielded bearings will be dirty again after your first day of racing.

Gif

[Walt Gifford]

If the mounting tubes are flat it would be fairly easy to retro fit a generic set of flat side bars. You will probably have to do some chop cut reweld to the new side rails but you’ll be working in 2 dimensions. If one or both of the mounting tubes angle up it will be near impossible to bend someone elses side bars to fit. In that case I would cut them off the frame and re-weld them flat to match up to something that’s commonly available.

Gif

[Walt Gifford]

Here we go, my favorite thing in the world, a box of junk parts.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamacarbbox.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamacarbbox.jpg[/IMG][/URL]

Someone tried to bore this out for WKA and went too far at .960″ perfect for me though. I ground out the choke stop and lettering on the venturi then smoothed it out by hand with sandpaper and polished it with a scotchbrite muff spinning in the drill press.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamacarbbody.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamacarbbody.jpg[/IMG][/URL]

I lapped the front, back and pumper surface with 600 grit and on the metering side I use a flat file and work around the nubs to take down any high spots. I also drilled the transition jet with a #55 drill to increase the fuel signal to the low needle.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamacarbmeter.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamacarbmeter.jpg[/IMG][/URL]

Here’s something I always wanted to try. I opened up the pumper area on the crankcase side to the edge of the gasket seem. Maybe it will give the pump more effective area.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamacarbpump.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamacarbpump.jpg[/IMG][/URL]

Now I mount the carby euro style and you have to do a couple of things for this. You have to drill new holes in the carb plate and you have to grind the cable arm to fit around the metering plate screw.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamacarbcablearm.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamacarbcablearm.jpg[/IMG][/URL]

You also need to cut back some cooling fins on the cylinder to clear the throttle arm and you need a longer pulse tube. This allows me to comfortably reach the needles while driving. It also makes it easy to clean the screen or change pumpers at the track.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamacarbcutout.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamacarbcutout.jpg[/IMG][/URL]

That’s it for now because it’s still freezing outside but I’ll get this thing on the no load dyno when the weather breaks. Hopefully the ground hog won’t see his shadow this year.

Gif

[Walt Gifford]

Any word?

[Walt Gifford]

If you can get the shields off and back on without bending them you’re golden. Just use any good wheel bearing grease. Don’t use gas to clean anything!

Gif

[Walt Gifford]

The thinner wheel will give you less rolling resistance.

Gif

[Walt Gifford]

Dang, I vote for Daves brake kleen method.

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[Walt Gifford]

Powder coat comes off between 250 – 350 degrees. To draw the temper from fully hardened 4130 you go to 600 degrees, up to that temp your frame is ok. To make it fully annealed you need to heat it red hot until it’s non-magnetic which is about 900 degrees.

It’s academic anyway, nobody can stand the smell of burning powder coat.

Gif

[Walt Gifford]

Agreed, aircraft paint stripper would probably kill a regular guy. Should only be used by someone from Jersey. Although burning paint off would be my last resort, you won’t change anything about the metal with a hand held propane torch.

Gif

[Walt Gifford]

Here’s a tool I use to spot face electrical connections. It’s a wire brush with a pilot. Great for getting corrosion off the aluminum coil mount.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamaigntwirebrush.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamaigntwirebrush.jpg[/IMG][/URL]

Ok Here for all time is how you set up a KT100 ignition. First put the flywheel on with the factory key installed. (Note the spot faced bolt holes.)

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamaigntspotface.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamaigntspotface.jpg[/IMG][/URL]

Now here’s the trick. Get the bonded paper cover off a Pitt catalog and cut two strips. The two together should measure .021″.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamaigntpapergauge.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamaigntpapergauge.jpg[/IMG][/URL]

Put the two strips around the flywheel. Push the coil in tight and tighten the bolts, top one first. That’s it, done.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamaigntcoilset.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamaigntcoilset.jpg[/IMG][/URL]

I put some heat shrink and spiral wrap on the plug wire where it touches things and wrap the TCI wire with electrical tape where it goes through the clip.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamaigntwire.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamaigntwire.jpg[/IMG][/URL]

I’m working on a TCI mount for the back of my seat but I need to get some good ground wire. Never had a problem mounting it on the engine though.

I’ll set the engine aside for now while I work on the stock appearing carb.

Gif

[Walt Gifford]

[quote quote=19062]any performance differences in the location of the plug when cutting the top of the head to lower plug into compression area.[/quote]

If there was an advantage there would probably be a new rule against it. I guess some guys are doing this to cheat the 11CC rule, impetuous.

I have no hard data but I do know you need a big increase in compression before you feel it in the seat of your pants coming off a turn.

You only get to extend the plug about an 1/8″ before you’re trapping air with the tech tool. If you use an extended tip plug it’s dang close to the piston. It’s easier to strip the head at the track.

I go for a clean bee hive combustion chamber centered on the bore for maximum fuel burn because, I know that works.

Gif

[Walt Gifford]

Try this

http://www.eccarburetors.com/pdf/HL%20service%20manual.pdf

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[Walt Gifford]

Here’s the finished head shape polished with 1/16th radius and gasket area lapped on a surface plate.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamaheadbowl.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamaheadbowl.jpg[/IMG][/URL]

Checking the deck clearance I can use a .005″ head gasket which is my thickness of choice. I made this tool that lets me bore out the ID for the bigger piston size. Basically you center the gasket then clamp a plate over it and bore it out. If someone makes head gaskets for these bigger pistons please let me know.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamaheadgasket.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamaheadgasket.jpg[/IMG][/URL]

Checking the head space to find I’ve got 10.5CC, should be trouble free for any kind of fuel or exhaust system I want to use.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamaheadCC.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamaheadCC.jpg[/IMG][/URL]

Gif

[Walt Gifford]

Got the cylinder on and the reeds move freely and seal quite well.

Time to get a head in life. Keeping with junk parts theme of this build I have gathered several heads over the years from various places.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/Yamahead.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/Yamahead.jpg[/IMG][/URL]

Top left is a rare find, an old 9CC head with no yamaha lettering and uncut the plug depth is .580″. Top right is the 11CC new style die cast head that came on the engine plug depth .550″. Bottom left is an old black fin head (SKS) Heli coiled with a very round and smooth combustion chamber about 11CC maybe made for enduro racing on gas with a pipe, plug depth .650″. Bottom right is an old style 11CC red fin head (Emmick) plug depth .540″.

The heat and pressure under the head nuts make the aluminum squeeze into the hole so, I like to spot face the top. First I drill with 11/32″ then I use a counter bore with a special pilot I made that’s .333″ diameter. The plug boss is cleaned with scotchbrite and not cut.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamaheadspotface-1.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamaheadspotface-1.jpg[/IMG][/URL]

Next I mounted each head on my home made billet mandrel and found the bottom two in the pic above to be off square and off center so much I can’t re-cut them using this method. I think some one re-cut these using a crooked spark plug for a mandrel. Note to self: don’t but heads on eBay lol.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamaheadmandrel.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamaheadmandrel.jpg[/IMG][/URL]

I’m saving the uncut head for an alky motor and the new style head was only out .005″ so, it seems to be the best candidate even though I wanted to use one of the denser castings.

[URL=http://s889.photobucket.com/user/giffy6/media/KT100%20SA%20blueprint/yamaheadsquish.jpg.html][IMG]http://i889.photobucket.com/albums/ac93/giffy6/KT100%20SA%20blueprint/yamaheadsquish.jpg[/IMG][/URL]

I want to run this engine on high test pump gas and possibly use a full wave pipe. Here I’m cutting the squish band to 17 degrees. I inked the gasket area so I can make a good measurement after each cut. More later.

Gif

[Walt Gifford]

You’re not measuring anything going from there.

Gif

[Walt Gifford]

Can you find a spot to drill 3 new holes?

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[Walt Gifford]

Chris, you have obviously never raced 360 bumper karts with a pack of aggressive pro drivers. Some of the hardest hits I’ve ever taken in 41 years of kart racing. It’s a completely different style of driving more akin to a pin ball machine or a bowling ally. That’s why they don’t mix rental karts with pro karts, they are battering rams and they bring out the worst in any driver.

Gif

[Walt Gifford]

Prayers for Schui.

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[Walt Gifford]

Nothing is easy.

Put a 3′ ruler across the bottom of the frame and measure up to the rear axle. make sure it’s the same height on both sides.

Take your ruler and put it across your king pin bolts or the spindle brackets then get behind the kart with your eye on the center line and sight the rear axle with the ruler and see if they are parallel. If not your frames bent. You might have to pull the enigne and/or seat to do this.

Next set your toe. Don’t try to measure the pitman arm just eyeball it to the 6 Oclock position and lock it down somehow. adjust your tie rods for zero toe.

measure the wheel base left and right, if it’s within 1/8″ your ok.

Make your spindle spacers the same top and bottom and set all the pills to neutral. Tighten the kin pin bolts with some weight on the front end. Set camber for 1 degree negative in a direction that will increase caster. If the left right settings are very different something is worn, bent or made wrong.

Some manufactures make spindles with different camber settings welded in or maybe the powder coating is worn in one of the camber pill holes maybe one side has a straight pill.

Find a set of tires the have the same roll out left to right at about the same air pressure. Now you’re ready for scales.

Gif

[Author]

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