[tony zambos]

We’ve run a whole bunches of ratios at BFR.  Best one is was a 15/79, hitting a max rpm of 14760 and a lap time of 1:18.75.  That was with a pre-09 motor.

[tony zambos]

Kevin,

If you haven’t spent time at kart shop talking to the owner or hung out around the tracks you’re thinking about visiting, suggest you do so.  See which classes interest you and talk to the karters.  Most will be willing to answer any questions if they’re not thrashng on a kart.  Good luck.

[tony zambos]

Jeff,

Go get them and please don’t hold anything back!  Totally agree with you.

[tony zambos]

Would guess that weight would hurt you more if you’re sprint opposed to road racing.  We run seniors with masters in our road race series.  Standing starts hurt the masters’ guys, but once they’re away, and it could be to their skills, they can the run competive times against the seniors.

[tony zambos]

Isn’t Infineon a road course? By chance, was the kart still geared for long track? The gearing might have prevented the clutch from locking up because there wasn’t enough speed.

[tony zambos]

Hate to tell you this, but you may have burnt up the clutch and drum by driving the kart around the block.  First, that is a dangerous thing to do unless you have a large parking lot in the middle of nowhere.  Second, by driving it around the block, the clutch may not have been fully engaged, causing the heat and smoke.  Is there any chance the grease from the bearing got into the clutch?

On a stand, the wheels probably always turn, that’s normal.  Hold the brake pedle down and see if the engine stalls.  If it doesn’t stall, the clutch is not locked up.

[tony zambos]

Rebuilding an engine and upgrading the clutch are two separate items.  The engine can be rebuilt using the old clutch, drum and gears.  Visually you tell the old from the new clutch and drum by the clutch drum.  The older drum will have holes in the front face, the newer ones don’t.  The gears should be replaced when the new clutch is installed, but the only way to know is to pull the side cover of the engine.  Below is the old style clutch.

[URL=http://s1139.photobucket.com/user/backlite/media/9b377d73-6a85-469c-ab77-fbc6a480b119_zps7497f5d1.jpg.html][IMG]http://i1139.photobucket.com/albums/n546/backlite/9b377d73-6a85-469c-ab77-fbc6a480b119_zps7497f5d1.jpg[/IMG][/URL]

Take the following link to see a new clutch.http://cometkartsales.com/Clutch-Parts-c-704/

 

[tony zambos]

A close guess on a senior Rotax would be around 200 lbs with a little fuel.

[tony zambos]

There are two chain an sprocket types, #35 and #219. Since there is space on the axle gear, it might be stamped 35 or 219.

[tony zambos]

max rpm’s about 12500.  that’s the peak of the power curve but it can be rev’ed to 14k.

temp between 140 and 160.

jetting with a 158 main jet should be safe.  watch the plug and exhaust color.  black is too rich and white is way too lean.  Look at some of the jetting programs out there.

power valve should kick in around 7000 rpm’s.

Down load the FR125 Operators manual.  It’s good, just don’t believe the jetting chart.

[tony zambos]

you are correct and longer flex for the bottom end. do you know how to measure the flex length?

[tony zambos]

+1 on TJ’s comment.  With the Rotax, you will be setting the carb up in the pits rather than adjusting on the track. At the track, you might have to change the main jet a couple of times a race day. You didn’t mention how much racing experience you’ve had. Adjusting the carb on the fly might be a distraction for a newbie racer.  As far as maintenace, both engines are going to require pulling the clutch drum off to grease its bearing, expect if you’re running an eleven tooth driver on the Rotax.  The carbs on both will have to be maintained. For the Leopard, a new gasket set once in awhile, check the pop-off, fulcrum height and you’re good. On the Rotax, the carb will have to be dismantaled and cleaned, plus the fuel pump will need be rebuilt. Two more maint items on the Rotax will be checking the RAVE valve for smooth operation and replace the exhaust packing.  You could put a sticker on the pipe to let you know when it needs replacing.  The Leopard doesn’t have those maint items.  None of the maint items on either engine is difficult.

Hoping you will enjoy your karting experience, so one suggestion.  Is there a less horse power engine you would concider.  If you’ve have no prior racing, you might be more comfortable with a slightly slower class. The engine wound be the big thing in the begining, learning how to drive and kart setup will.

[tony zambos]

Andrew,

You’re welcome.

[tony zambos]

Try a CRG dealer.

[tony zambos]

Joe,

This show give you an idea

http://i1139.photobucket.com/albums/n546/backlite/DSC_0019_zps7a6354b8.jpg

http://i1139.photobucket.com/albums/n546/backlite/159febb5-b6b2-478d-b21a-4b5d8b74b860_zps4241ffd5.jpg

http://i1139.photobucket.com/albums/n546/backlite/DSC_0022_zpsb3334f09.jpg

 

 

[tony zambos]

If you are going to attached it to the fairing, use the GoPro roll bar mount, http://gopro.com/camera-mounts/roll-bar-mount. The handle bar mount looks similar, but the roll bar mount is sturdier.  Hear many mount the camera to the rad with the sticky mount. Did see a posting somewhere to be carefull doing that because if the radiaor gets too warm, the adhesive could weeken. Except for the roll bar mount to the fairing, think about using some sore of tether

[tony zambos]

Last question. Any chance you and the family will be show up at a CES event this year?

[tony zambos]

Dave,

you are good! I am subscribed to the General section, but wasn’t to the vintage group.  Thanks

[tony zambos]

The scope of your decision on which engine mount to use should be based on more than attaching the engine to the frame.  You’ll have to consider the relationship between the coil and seat strut, the clearance between the pipe and the strut plus clearance beteen the pipe and the brake rotor.  Also consider where the pipe will rest in relationship to the rear bumper.  With the first tap in the rear, you DON’T want the pipe damaged or if you have a plastic bumper, you don’t want it to melt.  That’s why the different angled mounts.

I’m not plugging anyone, but we use an Odenthal two piece 10 degree mount as seen here, http://www.fastech-racing.com/odenthal-engine-mount-prmax-clamps-not-included.html.  Most of adjustments are done with loosening the two butterfly mounts. The bottom plate has slots for the bolts that attach the top plate. This gives a little additonal adjustment.  Once you have the engine mounted, then consider what gears you might be running and then get a chain.  You should be able to find the recommended gearing for you track and class, or ask on the Forum. You might wind up getting a couple of chains of different lengths to accomodate differenent tracks or limitations on the amount of travel you have for the mount.  Guessing that if you’re making five rear sprocket changes in a day, you might be lost and ask a compeditor.

Maybe there is a need for raising the motor an inch. I can’t think of one. It’s a water cooled engine.

See that while I was slowly typing, Chris has lent you a hand as well.  Good luck

[tony zambos]

Why do you want to change your braking system?

[tony zambos]

Use the following link to Comet Kart Sales to see the three tools you’ll need, http://cometkartsales.com/Clutches-and-Tools/.  You might want to try the Classified-parts forum as someone might still have these tools and no longer need. I used to have them but even I may have discarded them after twelve years of no use.

L&T is still in business.  Didn’t see the tools listed on their site, but you might wnat to call them or a distributor in your area or order them from Comet.  There also are probably many kart shops that sill have the tools on the self, waiting for a home.

http://www.ltmfg.com/misc/ltwetmanual.pdf

http://www.ltmfg.com/index.php.

 

[tony zambos]

Chad,

That was a one time deal when the seals were broken. It might have been better coordinated as we did have a certified Rotax engine builder at the track.

[tony zambos]

Bryan,

The last thing you want to is to put a wrench on the crank, opposite of the clutch. The crank shaft is two part and only pressed together. Knew a guy that used that method to install the clutch. His engine stuck every weekend, which there were several, until he found the problem with his technique. Get the proper fixation wrench and puller.

 

 

[tony zambos]

Sean,

First, be honest with yourself in assessing your engine building skills and the amount of time you have to do this.  Then think about the special tools you’ll need to purchase if don’t have them.  A short list of tools would be run out gauges, micrometers to measure cylinder size, v-blocks to check the crank, tools to press the crank apart and to put it back together, a pop-off gauge and a burette to measure cylinder volume.

If you decide not to do it yourself, contact other kart shops for prices and turnaround times. I would recommend L.A.D. Specialties in Bridgeview IL.  L.A.D. has been my engine builder for a very long time.  They’ve done everything 2-cycle I’ve owned.  See their web site for details on their services, http://www.ladspec.com/home.html. The only extra expense would be shipping. And if you want those special tools, L.A.D. can help you with that as well.

During the season you might want to rebuild the carb, which is mainly replacing the diaphragm and gaskets. This you should be able to do yourself with maybe a little help from a shop the first time.

Good Luck.

[tony zambos]

GREAT NEWS!  Enjoy your karting season.

 

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