Why Modern Four Strokes Suck; By Super Hunky

[huskibul]

  Lozza your not austentatious incognito are ya ?i thought interpol folded years ago

[mx250]

There is no real need for EFI on a 2T engine, anyone can replace the carb with a TB and program away but with lots of time and $ you might be marginal ahead of where you would have been with a carb.
Carbs with TPS on them date back to mid 90's, the trick is to interpolate them together with advance/rpm/power valve, which modern ignitions let you do.

I think there are advantages but probably not performance advantages but rather fuel economy advantages.

I know of someone who has put an EFI on a RZ350 and they found they had to do some strange and unexpected mapping to get carburetoration near perfect. In some engine performance perimeters. I some setting the fuel went richer, richer, lean and then back to rich. I think this is to do with the tortuous path between the TB and the spark plug which leads to some strange aerodynamics within the cases.

I would expect EFI to give smoother more controlled throttle response and maybe fuel economy rather than straight HP gains - still worthwhile to have when it comes to putting 'power to ground'.

I would love to try a 2t with it .

 

[pancho]

I have been a 4/ fan forever a preference which was reinforced in the 60's when my twin port jawa [which i had great expectations of becoming a star on] launched me into orbit over sorbent hill at moorebank scramble on full song having picked that moment to dislodge a crankcase seal! However I'm sure the end for 2/s is not nigh. If any one can get hold of the articles written by the very knowledgeable Mr Paul Dawson on the design advances evident in the current Evinrude 2/ outboard motors they will be indeed heartened. I don't know who's the brains in that outfit [OMC or whatever it's called now] but if he was into bikes look out!     cheers wally.  [The old OMC went bust I believe because of the Californian EPA,the new motors out-perform the 4/s while complying]

[All Things 414]

I just think it'd be a lot easier to plug your joystick/engine tuner thingy straight into the fuel injection thinga-ma-jig to tune it rather than have the guts of your carby strung out all over the place (like I always seem to do) on race day.   

[Lozza]

Jeff Mills(Hybrid on many forums) has looking to convert his YZR500 replia back to carbs after 18months of EFI frustration(especialy after it's been proven there is an easy 120HP with an ignition/pipes), 2T engines go the best a slightly richer setting (around 12:1 AFR),  with air soleniods and todays ignitions we can add or subtract small amounts of air or fuel at anytime. Who buys a bike and thinks fuel economy anyway?
Wally boats, jet ski's and snowmobiles all lend themselves to efi because of constant  throttle and stable pipe temps

[Slakewell]

I have a 2009 YZ 250 and I love it. It was a bit of pig till I had it correctly jetted and setup but now the power in smooth as, you dont need the clutch it just roll it on nice and steady. My mate Warren knows a bit about setup and he gave me a hand Photo below. I wont go back to four strokes again one big factor being I cant have a $12,000 bike I ride sometimes sitting in the shed but a $8,000 isnt so bad.

[Lozza]

You now need a t-shirt with that pic and the caption "Warren Willing touched my bike, now it goes faster !"

[Slakewell]

Dont need one I have the same as Warren it says Crash&Burn

[Marc.com]

PS Just caught up with MarcFX this afternoon,last seen fettling his Rickman Metisse beast with a hammer and grinder...

The big mistake the modern stuff has is they combined the gearbox and engine.....

[Viper666]

My daughter is a short arse like her Dad and couldn't get the gist of 2 stroke riding. She would try and just role the throttle on her 79 YZ125 and it just didn't work. So for the Western Regions, State Titles etc. I bought her a 2004 CRF250X brand new in 2005 and stripped it for racing just so she could have the button start. This suited her riding style much better and one of the things that sold me on the Honda was the separate gearbox to engine design. I would use it in the Vets at the WR's. I must admit I enjoyed riding it at the time but 4 strokes make you lazy. The other thing it has cost me a fortune in rebuilds. The head has had the valves done twice now even though the bike really hasn't done much work. My daughter gave up racing after she went to Uni. The last time it was started was over a year ago because I did the valve shims (That means another head job soon and not the good type). In all it would have been ran twice in just over 18 months. It just not as much fun to ride as my old 2 strokes (YZ125F & 250F), easier, but not as much fun.
Then last year I bought my son a YZ125 2006 model and decided to race that in a clubby in the Vets. I HAD A BALL. Holeshotted against those demon 450 4 strokes & held the lead for over 2 laps till exhaustion set in and was duely past. When I came off the track a mate said they could see me grinning. I had everything I wanted. 2 stroke power, light tight frame with brakes & suspension to boot. But rick got it wrong it was Yamaha that first thrust the "Modern" 4 stroke upon us, the 400F. Honda may have pushed the barrow from there but my guys started it. (Arseholes)

But we can do something, I cant believe I'm going to say this but, we can buy KTM or Husqvana both which still make 2 strokes. The mighty dollar rules everything and if Honda, Yam etc start losing sales they will rethink or get 2 strokes banned.

Well, have to go now, we have the Junior Vic Titles this weekend and its going to be Nucking Futs.

Viper666   I'm gunna need several beers to get through this weekend.

[Boyracer]

I know I used to go pretty quick on a free breathing '88 XR250 and TT600, I suppose it comes down to rider ability, maybe the only people who can take advantage of 2010 suspension and efi is the top 20 in the WMC.
Just go out and buy an old Maico 490 eh? lol..

[090]

it was Yamaha that first thrust the "Modern" 4 stroke upon us, the 400F.

I think the Euro's beat Yamaha even. Husaberg an Vertemati (VOR) started the shit fight I think. I was told that yamaha used Husaberg technology to base their bike on.
1997 veremati on the right.

[Husky500evo]

My opinion is that Husqvarna started the trend towards the modern fourstroke design with the '83 TE/TX 510 & TC500 . Ongoing development of this original design followed through to the watercooled 610 models and arguably Husaberg (by the Swedish engineers that left Husqvarna when it was taken over by Cagiva). Yamaha seems to get all the credit (or maybe that should be blame) for starting the latest fourstroke revolution with the '98 YZ400F, but Jacky Martens won the '93 World 500 MX title on a 610 fourstroke Husqvarna.

[090]

Took me a while to work out how to post this up. I love it and pretty much sums up how I feel about them.

[Davey Crocket]

Yea, but then Joel Smets came along and changed history with the Berg and started lapping everybody.......all of a sudden KX500's and CR500's where gonsky....now look, Antonio Carolli is flogging everybody on a 350 KTM 4 stroke (with alot of help from Stefan Everts), I personally think its going to go full circle again and 2 strokes wiil come back.