[Matt Martin]

Currently, i just weave around on my warm-up lap.  But, I’m not trying to win every race, just have fun on a budget.

When I ran oval races as a kid and wanted clean tires for the start of every session, we would use a heat gun with a scraper similar to this:

 

 

 

Or do you mean the rubber marking/chunks from off of the bodywork?

• This reply was modified 8 years ago by Matt Martin.
• This reply was modified 8 years ago by Matt Martin.

[Matt Martin]

Bill,

I did, the gap was set to about 0.015″ with a feeler gauge.

• This reply was modified 8 years, 2 months ago by Matt Martin.

[Matt Martin]

Thanks for the insight.

 

Upon rebuilding, i have double and triple checked the timing to make sure i don’t repeat the mistakes of previous.

 

More photos:

 

 

 

[Matt Martin]

Thanks, William.

There was about a 5mm section of the ring missing.  The locating pin was still in place, however.

I’m trying to figure out if the damage came from the hunk of piston/ring that departed, or maybe debris from elsewhere.  The big end seems all there, and I do run an airbox and filter.

I’ve read a few reports of coolant getting into the cylinder and thermally shocking the piston and leading to a crack, but i didn’t see any signs of where coolant might come through.

 

 

[Matt Martin]

no radio or windshield wipers in a kart.

[Matt Martin]

Frank,

 

I sent you a text about the GPS.

Thanks,

Matt

443.254.2574

 

[Matt Martin]

GPS (around or above 10Hz), and thermocouple inputs (water temp and/or EGT).

[Matt Martin]

[quote quote=91865]What do you mean by spindle hanger? The bracket on the frame that the kingpin goes through to hold all the spindle stuff together? The flat part almost parallel to the ground that the tie rod ends connect to on the spindle itself? The part on spindle the brake caliper connects to? Something else? And what am I specifically looking for? [/quote]

 

yes, I specifically meant where the kingpin goes through the frame, and how square that is with the frame, and if there’s any difference left to right.

 

I think the suggestions thus far cover most of what i’m saying, too – cracks, bends, etc.

 

As for checking the spindle bearings, I would remove the spindle and check the bearings through which the kingpin passes.  Make sure they aren’t binding, or knocked out of whack somehow.

[Matt Martin]

when you think about what gets loaded on the ground vs on the stand, the things that will have an effect on steering effort are spindle bearings and/or kingpin.  Whether or not that’s the bearing itself, the spindle hanger, the kingpin, or any combination of spacer arrangement.  are  you certain nothing fell out/shifted upon kingpin removal?

 

Have you tried loosening the kingpin and setting the kart down to steer?

I would definitely check the spindle hangers to make sure they’re not askew.  Think about it like this: if the kingpin or spindle wasn’t bent, that load is transferred into the tie rods, spindle hangers, and frame.

good luck, i would try to get the chassis on a frame table to double check how square it is.

 

edit: also look for cracks.  that seems a likely cause of binding which may only show up when the frame is partially loaded – on the ground.

[Matt Martin]

Depends on your engine.  Is it modified?  Is it ported.  What’s the head volume?  What’s the squish?  In general even stock K9s like a proper leaded race fuel.  They can run on ms98; but I run mine on VP C12 at 20:1 with Castor 927.

https://vpracingfuels.com/product/c12/

 

 

[Matt Martin]

probably one of the gimbal mounts out there.

[Matt Martin]

What’s a climent?

[Matt Martin]

[quote quote=90597]I would like to keep this along the lines of racing on kart tracks. You road racing guys see way more rpms then the short track guys.[/quote]

 

as Clark said, you have those in the opposite order.

 

[quote quote=90597]I would like to say I’m not trying to kill shifter kart racing. I’m just adding my opinion. That’s why companies have research and development departs. And it said HPD research and development, meaning they need to work out some stuff. (talk to them this would be a good time) I said nothing about going 4 stroke! Just show you what (I’m guessing Hondas future for shifter kart racing)[/quote]

 

I have worked in R&D my entire adult career, I know quite well how they work.

You posted a link to 4-strokes with no context – hence me asking what’s the point?  They’re the opposite of affordable. I think Honda is happy to just sell some easy-to-manufacture parts with no real assembly work and little to no repercussions on their larger business – if they weren’t you’d have guessed in ~20 years, they’d have tried to do something, anything different.

 

The future of shifter kart racing is made by the organizations who set the rules – if you want to race,  you have to race in a sanctioned group with a defined set of rules.  That’s why I told  you to view the existing thread about SKUSA’s potential direction in the future.

 

 

 

[quote quote=90597]And no, the most I know about manufacturing is CAD software! As for a public liaison, I guess I’m entry-level and hired my self. I’ve been watching this sport for years and don’t like certain things. FYI, Honda has a 2018 CRF 125 for $3,000, I think I might pick one up after I get my kart.  And Matt, I love that your having fun and I wish you happiness in this sport. But sorry, I don’t race for fun !!! [/quote]

 

Again, Clark got this one correct: if you’re not having fun, what’s the point?  I guess it’s easy to win when you’re making up your own rules and racing among  yourself.

 

 

it seems you’re trying to develop something without knowing the very basics involved with the supply chain and market dynamics.  if you want to change things you first need to have a business case (how to make it profitable).  Then you have to convince everyone your business case is better than others out there.  Then, you have to show that the racing will be entertaining and close.

 

Get to work!

[Matt Martin]

what’s your point?

 

the 4-strokes are even more expensive to repair/replace.

 

What is your experience in manufacturing and precision machining?  Have you managed a company before, or acted as a liaison between end-user and supplier in any official capacity?

 

I don’t mean to discourage you, but this has all been done.  KZ engines were an alternative to the Honda engines – those are now even more expensive.

 

Your best option is to learn everything you can, figure out your budget and buy the setup that fits that budget.

 

I have an old 2008 Intrepid kart with an old TM K9a (KZ engine) that I run with Woodbridge.   I’ve mostly pieced it together with NOS parts that I can find for sale on ebay and here.  I’m not competitive with the front-runners, but I have fun, and that’s all I’m really looking for.

[Matt Martin]

Check the thread just below this one.  I think you’ll have a better idea of the dynamics at play.

 

https://new.ekartingnews.com/forums/topic/is-skusa-moving-away-from-the-stock-honda/

[Matt Martin]

Did you replace the comma with a period for .com?

[Matt Martin]

Consider running frame protectors?

[Matt Martin]

is there any form of amateur motorsports which has retained, or increased their participation?

 

I think the crux of the issue is that people’s interests aren’t what they once were – for better or worse.  The other issue is that the smaller the middle class becomes, the smaller those interested in karting become.

 

I don’t think it’s become too technical – fragmented, perhaps.  Karts are still just a steel chassis with no suspension and a basic carburetor stuck to a dirt-simple engine.

With that said: yes, people who understand how to optimize those things – through more advanced technology – will always have an advantage, regardless of the simplicity.

[Matt Martin]

some kind of problem with balance – wheels or otherwise.  If it’s consistently 45mph it’s some sort of resonant frequency caused by rotational parts – engine (rpm), clutch, wheels, brakes, chain, sprocket, etc.

 

Or, if you happen to be at 45mph at the same point on the track each time, it could be track related.

[Matt Martin]

[quote quote=87537]

If the storage density limitation of batteries can be resolved, then this will be a nonissue, & ekarting will take on a whole new meaning. [/quote]

 

Thrilled for the prospect of this.

[Matt Martin]

limit fuel flow (via a spec pump).  CIK homologates everything else, i’m not sure why they wouldn’t do the same with the all of the EFI components – ECU, injector, and intake dimensions.

 

 

Also, people have learned to tune carbs, why wouldn’t the regular person learn to adjust injector duty cycle (assuming ignitions remain as they are)?

[Matt Martin]

Grassroots motorsports have generally been exempt from emissions regulations, i see no reason why that wouldn’t continue.

 

However, in the unfortunate circumstance that regulations get applied to karting, all karts of X or Y class would be bound by the same regulations, and I still see EFI as the way forward.

 

US karting tends to follow euro karting to a large extent, and I can see that trend continuing.

[Matt Martin]

Part numbers on the piston.  Have a look at the cylinder to see if its been ported.  Check the squish.  I’m not really familiar with the Hondas, but that’s generally how i’d check any 2-stroke to see if it’s been worked over.

[Matt Martin]

On a stock Honda?  You may be losing power running that over something like the VP 98 – unless the combustion chamber is setup to run that kinda fuel, it can be detrimental to performance.

[Matt Martin]

Steve, I have a mostly-complete VHSH 30 that’s just sitting around.  Let me know if you’re interested.

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