Messages

556

General Two Stroke Talk / Re: products that you have liked/ disliked

« on: May 04, 2010, 05:25:27 AM »

use turps to clean the filter

Hate NGK plugs love DENSO

557

Technical / Re: 1998 YZ 250 Reed advice wanted

« on: May 01, 2010, 06:32:39 PM »

I say what ever floats your boat use it. If you want a faster bike, A) Send it to some one who knows what their doing, or B) Ride harder! Other than that your not going to get factory secrets to get more horsepower. 

Or talk to 2T Institute!!

The first thing that he explained to me is that the more you learn, the more you find out that there is to learn. I feel like I got a college education in two-strokes while talking to him!

Aww schucks I'm getting all embarrased G-Money no offence, I have read that many times about V-Force and the incinuation is it's an 'inferior' product by virtue of where it's produced.
I should post a pic on how to make a 'poor man's' v force
I didn't know that reed instuments use carbon fibre reeds also

558

Technical / Re: Carb Size

« on: May 01, 2010, 06:17:23 PM »

Port work won't help low end power increasing the compression ratio is what you want at high altitiude

559

General Two Stroke Talk / Re: 2011 ETEC Bombardier engine..

« on: April 29, 2010, 07:10:37 AM »

Can-Am was always the horsepower king.  They put out big numbers and reviewers were always impressed with the motors (which supports my advocacy of the rotary-valve).

Unfortunately to reed valve itself and reed petal technology has caught up and in most cases eclipsed the humble rotary valve. The HP king is Aprilia RSW 125/250 GP road race bikes, they have always been rotary, however the reed valve KTM FRR 250 was soooo close in outright speed. Figures ranged between 120-110RWHP

I would love one (and some snow) but no castor smell is a downside

560

General Two Stroke Talk / Re: Project Two 50 Update 2

« on: April 27, 2010, 06:56:37 AM »

Here's a pic of a KX 450 that will be featured in the upcoming edition of VMX magazine, should be some better pics in the edition.



One thing I will say about the pipe DO NOT have it stamped or hydroformed. They are not better nor do they make better numbers. Also the join at the end of the belly and the baffle cone must be clearly defined and 'sharp', as shoud the belly and various stages in the diffuser cone.

561

Technical / Re: 1998 YZ 250 Reed advice wanted

« on: April 27, 2010, 12:31:36 AM »

I think Steve Tassinari would disagree very strongly his products are made in Europe(so what if they were?)

562

General Two Stroke Talk / Re: Project Two 50 Update 2

« on: April 27, 2010, 12:26:08 AM »

Well, it sounds like we have a proper scientist in the forums.  I remember the last one we had... fairly angry sort of guy I seem to recall.

It's a part of the job description. Yeah I'll post up a few pics, I don't have that many dedicated MX pics, and thanks for the kind words TotalNZ(getting cold there yet??).Well you know the help you can call on John
I don't think it will be just a matter of 'more' this or that but a case of 'optimising' the engine to what the rider wants, speaking to Todd(which was handy BTW) he said Mike has already topped out in 5th but can't run lower gearing because of acceleration being compromised.If you can get higher top speeds without loosing mid corner to corner exit speed you will do very well I think. Having no guess work with either engine or suspension will be worth a few tenths a lap.You will inevitably say on thw way home "what we should have done is........" minamize that sort of thing is helpful also.
Oh well that pipe won't make it's self................................    

563

General Two Stroke Talk / Re: Project Two 50 Update 2

« on: April 26, 2010, 06:01:37 AM »

In addition we have a guy that is designing a custom pipe specifically for Project Two 50.

hey I'm not just 'some guy'  I'm confident I can match all those dyno charts  with about 5HP more on top.............

564

Technical / Re: What two stroke pre mix is best?

« on: April 02, 2010, 04:45:07 AM »

This is a cylinder last ran in 2001 or something been sitting round ever since, some everso slight surface rust on a cast iron bore. NOTHING protects like castor oil. I have yet to have any issues with this varnish everybody talks about?
Have recently sorted big end issues with a bored out KX60 it would last a lap and a half on TTS at 30:1 runs for many meetings on Castor at 20:1

565

Technical / Re: nikasil or sleeve? which ones better?

« on: March 11, 2010, 05:19:53 AM »

We've all heard all the reasons for years about how plating was so much better but the fact remains that this company have fitted a helluva lot of liners to modern bikes and there's been no problems and that's difficult to dispute. Theory is fine but I'll go on practical experience (if available) every time.
Again, hard to argue with!

I'll give you practical experience EVERY time someone uses an iron liner in a cylinder designed for Nikasil they ping their heads off when they get hot. The last poor sod that told me about his WR 250 that had been abused is such a fashion, he was shattered to find out that his cylinder could be welded machined and replated for 2/3rds the cost of a resleeve.
You can also Nikasil over cast iron liner when you are on max piston size.
Show me the 50 odd HP 125 GP or 110HP 250 GP engine that uses cast iron liners
 Fixed gear 100cc kart engines are not anything special, an old KT100s engine will go near that, step up to Rotax Max,ICC or Superkarts and you will see the difference between cast and nikasil.
I take old iron liners out and replace them with plated aluminium liners, they handle higher compression ratio's and a cylinder head temp gauge proves they handle heat for longer. Practical enough for you?

566

Technical / Re: two stroke porting

« on: March 11, 2010, 05:02:54 AM »

V force 2 works best for high rpm all thoseGP 125's can't be wrong.

TSR software is OK but it doesn't look at the engine dynamicaly, Port 2000 is a good place to start, but by no means has all the answer.For instance it doesn't take into account the ignition and what changes in the curve do.
To answer the question, there is no short answer, no quick fix and no short cut.Everything has to work in harmony. There are a few things you coud try first would be to retard the ignition slightly and then chop 10mm from the header of the pipe.

Yes the mighty disc valve is the go although reed technology has caught up with discs lately

567

Technical / Re: Ok, you decide Carbs, FI, or DI

« on: January 27, 2010, 03:42:06 AM »

I know this is straying off the DI debate a bit but I'm not sure you can apply that as a hard and fast rule across the board.

I don't care if you stray off, the info you gave was awesome.

Back in 1993, there was a certain NSR500 with EFI. Shinichi Itoh rode it, and Doohan said he wasn't a R&D rider, he was racing to win. Well it first debuted in the Japanese GP, Wayne Rainey said the bike sounded like a cruise missle coming up and going buy. He also said his YZR500 was being pulled towards Itoh's bike when he was coming from behind him, and then he would rocket by and Wayne would try to get behind him to draft. 9 out if 10 times Rainey couldn't draft Itoh because the bike was fast and would gain about 7 bike lengths. But after the end of 1993 Honda pulled the plug on EFI, not because it didn't work but because of Mick Doohan who wasn't into testing new stuff. Also the NSR 500 of Itao was the first to break 200 mph at Hokenhiem. Funny stuff ain't it?

The problem with open loop fuel injection on a race engine is the hot/cold pipe dynamic in the engine. Worked OK at Hockenheim and Suzuka but never worked when mid range part throttle fueling was of importance.

568

Technical / Re: Advice For Best Exhaust With Huge Top End Hit

« on: January 27, 2010, 03:30:40 AM »

Hi I have a KX 250 yr 2000 and my brother has a YZ250 yr 2004. I like my engine powerband to come on like a light-switch so there is little power down below then it suddently kicks in with a crazy hit and a hugh power surge in the higher RPMs. I was just wondering if anyone knew the best pipe to get the engine tuned like that? I know the gnarly FMF type pipes are supposed to give more bottom end torque at the expense of higher end revs - but does anyone know a pipe that would do the opposite? 

Thanks!

Wire the powervalve open. Best pipe will be one designed to work like that, not a biscut cutter off the shelf pipe.

569

Technical / Re: Oil and ratios

« on: January 27, 2010, 03:28:02 AM »

Chokey something very similar to Pre-mix 101 was originaly posted by a fellow called 'Spanky' ??

Have always will always use a castor/synthetic blend at 18-20:1, oils have not realy changed nor have crankpins and needle rollers.Nothing provides the same protection as castor, that begins to work when sythetic /mineral cries enough.
Yes 'spooge' is a indication of incorrect jetting and ignition. GP125's blow a whiff of smoke when the light goes green, that's it in 45mins of racing.