TSP head mod - 2018 EC250
 

After help from my buddy, Nate - a bike mechanic - I learned the slide was too high, giving a lean condition on closed throttle. After winding out the idle screw the bike is running perfectly.

Squish - 1.35mm. The bike is whisper quiet down low & so much smoother - it was already smooth as.

Clean, strong power all the way through, no spooge. Brilliant.

So happy this saga is over! Big thanks to Nate & Dave and Jason at TSP, Melbourne, Australia.

Here?s the head.

Looking for a list of USA shops providing squish band service.

Millennium.

Millenium http://www.mt-llc.com

Web site isn’t helpful. I sent an email.

info@mt-llc.com

Edit: I called and talked to a non-tech. Squish mod is $81. Waiting for details from the tech.

Millennium Technologies LLC
1404 Pilgrim Road, Plymouth WI 53073
phone: (920) 893-5595
fax: (920) 893-4830

Let us know turnaround time, if they provide that information.

I just put the RK Tek head on mine and it’s simply amazing. Bottom end is nuts and then it’s just a nice smooth pull all the way up through the RPM’s. Power was increased across the board. I dare say it is very “450ish”. If I had it to do over, I would just send my stock head to them and have it modified to accept one of their inserts. That service is only $125 vs $325 for the billet head like I have.https://uploads.tapatalk-cdn.com/201...3e91b06b7d.jpghttps://uploads.tapatalk-cdn.com/201...d0a7a08379.jpg


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Very nice stuff!

Is there anything wrong with just going for the $150 rechambering?

Why is this better than the Millenium service?

RK-Tek for Gas Gas:

https://www.2strokeheads.com/index.p...formance-heads

https://www.2strokeheads.com/images/...%20CHEAT-1.jpg

The re-chambering offered by RK Tek is what I was talking about. They cut your head to accept an insert.

I had an RB head on my 05 and S3 heads on my 11’ and 15’. The RB head doesn’t offer much of a performance boost. It just smooths out power delivery and makes the bike easier to jet. The S3 gives some extra bottom end by increasing the compression. The RK head changes everything. Also it gives you the option of having multiple inserts cut. Say you want to run race gas normally but sometimes only run pump gas, you could have an insert cut for both. Or maybe you ride and different altitudes. I know the majority of us would never change heads for these scenarios but the option is there. Guess my point is, it offers more tuning options.
Most guys don’t bat an eye at spending $250 on a FMF gnarly pipe to gain a tiny bit of bottom end. Why not drop $150 or even $300 on something that offers far more performance?


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I don?t want increased compression. I want a good squish set to Arizona?s crappy 91-Octane pump gas.

That means cutting the head while opening up the combustion chamber to maintain a specific compression.

That’s the glory of an RK Tek. Just call him and tell him what you’re after performance wise, what fuel you run, and what altitude you’re at. He will cut an insert specifically for you. It’s not some canned head that is setting on a shelf. He doesn’t have any inserts pre-made, he will cut your after he talks to you.


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So $150 for the machined head and insert?

How do they want the squish measured? Rosin core solder impression?

What about the supposed difference between the XC and EC piston (something about a different dome shape).

Rick, after my dramas with crown height I would recommend whipping the barrel off so you can mic up the piston & get an accurate measurement there as well as negative deck height.

FWIW, Dave Macarthy at Two Stroke Performance here in Australia reckons the comp is too high, period, on the 2018 300. He lowered it on gassernate?s bike (not sure to what) which is now running quieter & stronger than ever. Dave also said my bowl shape & compression (stock - 13.5/1) should see the bike able to run well on 91RON. I will test it one day, but currently run 98.

I had an S3 head on a Beta RR250 a few years ago & getting the head set up specifically for my bike has yielded much better results than bolting on one of 3 inserts.

Wow. Compression too high ??

Even with a sad 2mm squish or would that be if the combustion chamber wasn?t more aggressively opened up?

I was hoping to just do a rosin core measurement a la RB-Designs, but I?ll do what I must.

I?m referring to the EC250 only. EC300 has a flat top piston, afaik.

It is weird - totally counter-intuitive to think lowering compression will give smoother & sometimes stronger power.

We would need a dyno to confirm the results, but we are talking about inefficient combustion compared with very efficient combustion. Even this is surely enough to cancel out the drop in bottom end when lowering compression.

It is far easier to buy a solution off the shelf and fit it up & I’m certainly not saying S3, RK-Tek, etc don’t do exceptional work. I have gone 180 degrees on this - from bolting on stuff to understanding why you get the gains from setting up your motor for YOU & your specific requirements.

I would prefer simple: reshape the stock head and be done with it.

I have done this three times in the past ? KDX220, and two GG250s.

All to good effect.

Same here. I've had great results with RB's mod on two KDX's and my previous GG EC250. Simple but they all made better power and were easier to jet.

So, which one for Simple?

Millenium or RT-Tek?

Gibnut, do you have any pics of the stock head? Ive just picked up my EC250GP and am happy with how it runs, but I do know how good the TSP head mod is after getting it done on my past few bikes.

Anyone had the squish measured on a '18 250GP?

I would have loved a GP!! Unfortunately only a plain jane EC coming my way.. I'll probably pull the head, measure the squish, see how many cc's she holds and all that jazz. Considering getting a local machine shop to turn the head rather than sending it to the other end of the country and back.

Before & after, squish 2.25mm stock, 1.35mm now.

Jake, your compression will be in the mid-high 15?s if you shave a mm off and do nothing else. Ping & run-on almost guaranteed.

It's nothing new Gibnut.. This'll be my 3rd 250 engine build..

Whoever I get to do the work will be reducing the squish, matching the band to the piston angle and opening the chamber up to correct compression.

Sure to be someone local with a CNC machine who'll take on the job. Just a matter of how long it takes em and how much they charge.

Sweet as.

Or I'll just send it to Dave at TSP! How was his turn around time? It's a long round trip from here.

Good luck with customer service from RK Not worth it!!!!!!!

Funny, I deal with Kelsey on a few matters with my sleds and he's always there. He has a different demeanor, tells it how it is and won't take customers crap. Like more business people should. The customer is not always right, even when they think they are...