[Dan Davis]

Still available Scott?

[Dan Davis]

Sorry to hear this news.
Rest in peace Lenora.  It was a great pleasure to have known you and Wally as well as the impact the Wallen family had on kart racing.
Condolences Buddy.
Dan

[Dan Davis]

Thinking about it…….. I’ll be there just don’t know if I’m bringing a CIK125 or TZ/P1 250.  Hmmmm……anyone hear from Johnny West lately?

[Dan Davis]

Whelp, I was able to get a kart somewhat prepped for Hallett……..I plan on a nice relaxing weekend with some friends I haven’t seen much this year and some playing around with a superkart on a smoother Hallett.  We’ll see.  I wouldn’t think of bringing the twin superkart there in the past due to the surface condition (for fear of too many one off parts breaking on the kart and myself)…….but I think I’ll give it a try.  Looking forward to seeing you all there. ;-)

[Dan Davis]

I use PowerPad blue pads all the way around on my Anderson Maverick CR250 w/dual rear disk and depending on the track they last for a few race weekends at least.

On my TZ250 powered P1 equipped with VDot brakes (single disk 6 piston rear caliper) which are similar to Kelgate brakes, I use blue pads in the front and gold in the rear.  The P1 always had too much rear bias for me with whatever pads came with the kart in the rear and the gold improved that issue.  The pads on it wear similarly to the Anderson.

One track I typically run on, Lake Afton,  has very long strait (.8 mi. or so) with a 45 mph 90 deg. + turn at the end that really pushes the brakes…..the P1 with me in it weighs approx 500 lbs……I’ve gained a few pounds over the last few years.  ;-)

Pierre has a few compounds, give him a call to see what he has to offer.  The work very well for me.

[Dan Davis]

I see it has the $60 spark plug boot…..and the $45 spark plug beneath it no doubt.  Awesome! ;-)

[Dan Davis]

Andy!

Very nice description of your…….”engine specs” Ian!

[Dan Davis]

Hello?  Anybody out there?…….

[Dan Davis]

Very nice looking package Ian!

[Dan Davis]

I’m thinking that most things mounted to the smooth running CR250 take a beating to the point of failure over time. ;-)  Still the best option for competitive 250 superkart racing with more than 2 entries IMO.  My current mount (about 10 years old) all but came off of the chassis in pieces.  That’s not too bad of a life cycle considering the abuse.

I personally like the shorter mount better to keep the engine lower in the chassis….but the carb angle pretty steep in that position.  I’ll be trying the lower with my case ind. project using a floatless pump around arrangement first….if that proves to be unsuccessful then I’ll raise the engine and use my Dellorto.

[Dan Davis]

There is a pic of both Case Induction (taller) front mount, and cylinder induction (shorter) mount here…

http://eknclassic.com/viewtopic.php?t=66607&start=390

A little past half way down.

[Dan Davis]

I mount mine between the two unused tabs in front of the engine mount tabs.  These are below the pipe and to the right of the fuel tank.  My CDI is mounted down there as well.  I have an aluminized ceramic heat shield over the top of both to shield against radiant exh. heat.  I use two angles mounted to those with vibration isolators between the coil and the angles for mounting.  I don’t know if these tabs are on all years of Maverick chassis.  I just got tired of mounting the coil on the engine and ending up with periodic primary wire breakage at the connector.

[Dan Davis]

That’s a pretty accurate inclination there Chris ;-) ……In fact, I need all the freebies I can get to even hit a couple races throughout any given season but this kind of stuff is just about as much fun for me as piddling about behind the wheel.

Yep, I plan on using Yamabond between boot and adapter as well as the bolt heads.  The boot is a Mikuni/Kimpex 07-105-01 which are common on snowmobiles and cost as little as $10 delivered.   If I were to use Aluminum in the future, I could eliminate the nut pockets on the inside and just tap the holes.

Next up, build fixture to deck couple of cylinder heads, cut o-ring grooves, and comb. chambers on a CNC machining center……luckily I have a buddy that sells those things and has one in his showroom to demo at the moment…..that equals free rent and maintenance for him on one of my CIK125’s for a couple of events. ;-)

[Dan Davis]

Yep, and I’m quite sure Jim McMillan would add a big “+1” to the $$$ statement with regards to the development they went through with their TRX250 project.

[Dan Davis]

Never mind……I just looked at some decent pictures of a 2005 cylinder for sale….it appears that the bolt circle and bore are concentric unlike the 2002-2004 version.

Flat Top piston and chamber it is!

[Dan Davis]

That would be good because I will be in need of a RH sidepod in black in the near future that was damaged.  Keep us up to date.

[Dan Davis]

So sad. RIP Cliff.

[Dan Davis]

Great Job Bobby!

Bettering Brian’s F125 best time and beating him across the finish line would have gotten ole Wally’s shorts in a bit of a bunch!  ;-)

[Dan Davis]

Eh….that’s just additional downforce Andy. ;-)

[Dan Davis]

[Dan Davis]

That Anderson Maverick Div. 1 chassis w/Wiwa Gas Gas set the record all by itself??  Wow!  What guidance system was used? :-)

[Dan Davis]

Mark,

I have yet to  fit the case induction mount  or engine to my kart but I suspect it can be made to fit beneath the pod.  I have only used the pump around arrangement on my cylinder reed engines with no issue.  I plan on buying both the taller mount and the shorter mount to experiment with.  The taller mount appears to be about an inch or so taller so I should be able to compare carb angles and exhaust clearances. Maybe Ian will chime in in the mean time.

What pipe are you running?  I am using an older Anderson/Viper 2 piece pipe that can rotate around the header and at the center of the 180 deg bend So it should be able to be adjusted to adapt to the engine height change.

[Dan Davis]

Experimenting with 3D printing to make a carb. rubber adapter for 2005 CR250 VF3 reed valve.  It is angled slightly downward but is tough to see in the photos. The material is a bit on the brittle side but seems to be impervious to intended race fuel.  It is a urethane acetate material.  There is a better materiel available that has similar properties and is less brittle but I don’t have access to that at this time.  Hopefully, thickness of adapter will overcome any potential damaging stresses and vibration.  Time will tell.  Fun-Fun!

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[Dan Davis]

Yes,  McMillan Racing who developed the Nemesis superkart chassis some years ago did some development with the TRX250’s.  I believe the only real benefit was the counterbalance shaft and a six speed transmission.   If I remember correctly there were transmission issues with regards to gear ratios not particularly suited to superkart racing.  I think they developed and had gear sets made at a high price which offset the benefits to none and popularity never took off.  There may have been other issues leading to it not becoming popular that I am not aware of.

[Dan Davis]

I’m back!
Well, it’s been a year since I’ve worked on my case induction CR250 project….it’s just been sitting there patiently waiting on me to get back to it while I drove a 125 and a TZ250 kart at select events last year.   I am currently working on resolving my cylinder head issue for a 2004 CR250 cylinder for which I intended to fit a 2005 domed piston.

As I began modeling a combustion chamber to cut into a 2004 cylinder head to use the domed piston, I realized that I would need to cut the chamber excessively deep into the OEM head to obtain a 20cc CCV (without spark plug hole, approx. 22cc’s with) and a 1.2-1.3mm squish clearance.  This is mostly due to the piston dome consuming approximately 7cc’s of volume keeping in mind that my chamber must begin flush with the cylinder deck rather than inset into the bore due to the existing porting in the cylinder. The piston depth in the cylinder at TDC then is equal to the squish clearance value.
I have concerns that this will make the combustion chamber casting thickness too thin and possibly even break through since I have not cross sectioned a head to verify casting thickness.

This leaves me with a couple of options to use this cylinder:
1. Use a flat top piston to gain approx. 7cc’s of volume.  This is probably the easiest option but I really would like to use the 2005 single keystone ringed piston.
2. Explore a different head.  Expressly, the 2005-2007 cylinder head for which I know nothing about except that it was designed to be used with the domed piston I would like to use.

Based on previous posts by our favorite technical expert on CR250’s, I think I already have a clue as to the answer of my question….which is no but don’t have a definitive answer, so here it goes:
Can a 2005-2007 cylinder head be fitted to a 2004 cylinder?   I’m guessing the answer is no because of the offset bore/chamber relative to the stud pattern on a 02-04 cylinder (assuming that the pattern and or bolt circle is even the same) but I haven’t seen one to be able to tell.
Thanks in advance,
Dan

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