GasGas and the future of 2-strokes

[Berkyboy]

It's always interesting working with Boni, the man behind the GasGas two-stroke engine, from the GasGas factory and this North American WEC trip, as usual, has been very rewarding so far.

Boni loves to talk GasGas motorcycles and his technical knowlege about GasGas two-strokes is incredible.

We've had a busy couple of days here in New York and last night, after the Hancock, NY, WEC closing ceremonies, he and I shared a couple of "ice cold Buds" and talked shop.

After a couple of beers our conversation turned to the future of two-strokes and he assured me that GasGas will me the stricter European Homologation emission rules that will require two-strokes to run on an oil mixture of no greater then 1%, or 100 to 1.

He stated GasGas has succesfully been running two-strokes motors at 100 to 1 ratios for years and that given proper jetting thay have run stock GasGas 200, 250 and 300 engines (with the current stock cases, cranks, connecting rod bearings, piston, rings, reeds carb etc.) with out crank bearing failures at oil ratios of as little as .03 percent.

Of course he could not varify or deny if the 08's will be able to run with 1% oil mixtures but he said they have succesfully run engines for hundreds of hours under load on dynos without any troubles. The only exception was the GasGas 125 motor which is still in development.

To make my above statement clear, he did not say that the '08 GasGas will run with 1% oil mixtures he has said that they have been able to do it.

It's also interesting to share some of our tuning tricks with him and this week he will get a chance to ride one of our MC250 / EC300 hybrids complete with a Rekluse clutch, some LTR goodies and RB Designs carb mod to mention a few.

So far he's reluctantly given the thumbs up (remember they have been working on similair improvemets as well and he jokingly hates to admit that someone else, especially a group of Americans, came up with something that works) to the LTR impeller, Motion Pro throttle cables, ceramic main bearings and the RB designs carb mods (although he had to rejet a little to meet his standards.)

 

[Boomhauer]

That is some great info! Thanks for sharing Steve.

 

[Brian VT]

My buddy, a shop owner and mechanic, has been running Amsoil (Sabre?) at 100:1 in his EXC300 for 2 years. He said that it doesn't sell because people feel like they are taking an unescessary chance.
I still run Amsoil Dominator at 50:1. LOL !

 

[tds2277]

Just because the Japanes companies are not going to sell the 2T anymore so they say....Does not mean the rest of the MFG should follow that is for sure....GASGAS and TM and even KTM are still producing 2T for 2008, I do not see them going anywhere still for a long time...there are too many people that love them...and the cost of maintenance is 1/10 of the 4T. I still love the smell of Blendzall in the morning MMMM

I believe in 2008 there will be more 2T sold than what was sold in 07...especially for GNCC and Enduro WEC Races, that is what is selling 2T for these classes


Motorcross im going to say the 4T....that is what im hearing...and that is what is selling for motocross

 

[Berkyboy]

We sell a lot of Amsoil 100:1 as well but the people who buy it are looking for it. Its a hard sell to anybody who isn't looking for it.

It was interesting to hear from Boni that GasGas isn't afraid to warranty their bikes once the 100:1 is the standard.

 

[gasgasman]

Dang Steve,you have a tough job.

Manufacturers need to "go back inside the box".
The answer is oil injection. IMO.
The current 2 stroke outboards run anywhere from 150:1 to 50:1 with oil injection.
I realize that they run at constant speeds, so the lean ratios can work for that apllication.
Remember the Yamaha RZ350? They had oil injection with cat convertors.

The beauty of a two stroke is , the bearings are always getting fresh lubrication. Not like a 4 stroke where the bearings are bathed in worn out oil with tons of contaminants.

 

[GMP]

Ceramic bearings are a big part of it. Need much less lubrication. Main size ceramics have been around a few years, but I don't know about lower end rod bearings in ceramic, anyone? Different kind of load.

Back a few years when I was heavily into deep shipwreck diving, we would mix our own breathing gas. The last step involved topping off the helium/oxygen with air to over 3500 PSI. This required the use of air run through a special filter, or from a (then new) totally oilless compressor, to avoid a disaster. All internal bearing surfaces were said to be ceramic. So the tech exists, question is is it applicable and affordable.

 

[gasgasman]

Glenn.
Have you heard about air bearings?
Won't work on bikes. But makes you wonder.

http://www.westwind-airbearings.com/airBearing/index.html

"What is an Air Bearing?

An air bearing is a non-contacting system where a gas film (typically air)
acts as the lubricant that separates the two surfaces in relative motion."Types of Air Bearing

There are two main kinds of air bearing:


Aerostatic:

Externally pressurised: A separate external supply of air is fed under
pressure between the two surfaces being kept apart.


It is a continuous flow system where pressurised gas from the source
flows through restrictors into the clearance between the bearing surfaces escaping to the atmosphere at the outside edges of the bearing.


Types: Simple orifice fed, Pocketed orifice, Slot fed and Porous.





Aerodynamic:

Self generating: The supporting film is generated by the relative motion
of the two surfaces being kept apart.


An aerodynamic bearing can be of several types. The design characteristics
differ greatly between journal and axial bearings and they can suffer
problems of instability.


Types: Simple cylinders, Tri-lobe, Grooved (axial / herringbone / spiral)
and Stepped.

 

[GMP]

Yes. Some of the equipment I design/program uses turbo molecular high vacuum pumps that spin up to 100K RPM and use air bearings. Neat stuff.

 

[TooFastTim]

I heard about these ceramic bearings and read somewhere that they have them running in a 2S. Still won't keep the bunny huggers happy though.

 

[Berkyboy]

My understanding is that the new "Euro 3" emission standards start on January 1 2008.

Due to the fact that that is mid year in the '08 model year I would suspect that GasGas, Husky, KTM etc. will be cranking out as many 08 bikes as they can before the end of the year.

It sounds like GasGas will be using a combination of catalytic converters, air mixing valve, throttle stops and possibly a tps carburator to meet the new standards. All of which can be removed by the end user in about an hour.

Of course this is going to come at an increased cost in production so if your thinking of a new ride I'd be buying either an '07 or an early production '08.

 

[roostafish]

100:1. A diversion from the original topic, but I have to chime in on exactly that. I am (self proclaimed) Mr. Crank bearing. I've blown more crank bearings in more bikes than I care to admit. I was sponsored by a nameless company that was pushing a 100:1 oil and insisted that I run it at that ratio. I was riding a KTM 250 EXC at that time and blew a crank bearing for the first time on that bike, just days before a national ISDE qualifier. I had a replacement for the weekend and decided on the short notice, and the need to drive a long way, to just put my bars and hanguards on the bike, rejet, and ride the rest stock. It was fine, but day one the awful stock tires haunted me. A quick tire change that afternoon to some good meat and day two was better, but guess what? Yup, Mr. Crank bearing again. ON A BRAND NEW BIKE. It was unbroken in, but still, it's a two stroke. It was too lean of an oil ratio.

I've lost plenty of GG crank bearings, on one bike. It was my second GG. An EC 250. I lost three, then sold the bike, the new owner lost one just weeks after getting the bike from me, now he has a new case half and ceramic bearings. No problems since then.

At any rate, I won't be running 100:1 until GG recommends it for my next new one.

 

[GregM]

100:1. A diversion from the original topic, but I have to chime in on exactly that. I am (self proclaimed) Mr. Crank bearing. I've blown more crank bearings in more bikes than I care to admit. I was sponsored by a nameless company that was pushing a 100:1 oil and insisted that I run it at that ratio. I was riding a KTM 250 EXC at that time and blew a crank bearing for the first time on that bike, just days before a national ISDE qualifier. I had a replacement for the weekend and decided on the short notice, and the need to drive a long way, to just put my bars and hanguards on the bike, rejet, and ride the rest stock. It was fine, but day one the awful stock tires haunted me. A quick tire change that afternoon to some good meat and day two was better, but guess what? Yup, Mr. Crank bearing again. ON A BRAND NEW BIKE. It was unbroken in, but still, it's a two stroke. It was too lean of an oil ratio.

I've lost plenty of GG crank bearings, on one bike. It was my second GG. An EC 250. I lost three, then sold the bike, the new owner lost one just weeks after getting the bike from me, now he has a new case half and ceramic bearings. No problems since then.

At any rate, I won't be running 100:1 until GG recommends it for my next new one.

So what ratio do you run at?

Greg

 

[GMP]

Of course this is going to come at an increased cost in production so if your thinking of a new ride I'd be buying either an '07 or an early production '08.

Why can't they make a run of North American spec bikes at a reduced cost? If KTM does and GG doesn't, that additional price increase over what is alrteady there is going to be very tough to justify for a customer, even if the bikes are better, and they are. IMO they have to do this.

 

[Berkyboy]

roostafish

I respect your opinion and agree that pre-mixing leaner for the sake of using less oil can be a recipe for engine failures I would never recommend an owner of any 2-stroke use a ratio anything less then what they feel comfortable with. More important is the quality of the oil that they are using.

Kyle Redmond's and Chistophe Nambotinss bikes were both run at 50:1 (Golden Spectro synthetic) during this years WEC. Redmond's bike was using the standard "stock" crank bearings, which can run at 50:1, while Nambotin's bike was using the newer crank bearings, which can run a 100:1 (those bearings will be stock on bikes that will be built after January 1 2008.)

In between the two WEC rounds both bikes were given fresh top ends and the mechanics working on the bikes commented on the nice coating all the internal surfaces had (using Spectro synthetic oil) pointing out that it was similair to what they would find with a cheaper non-synthetic oil mixed at say 24:1 or 32:1.

According to Boni, head GasGas 2-stroke mechanic, GasGas has been using these newer crank bearings on their factory race bikes for years and have had no greater failure rate while running at 100:1. Remember the reason for the 100:1 "recommended" mixture is to meet new Euro 3 emission standards.

 

[topari]

roostafish
According to Boni, head GasGas 2-stroke mechanic, GasGas has been using these newer crank bearings on their factory race bikes for years

What do you know about these newer crank bearings ?

 

[GMP]

Ceramic bearings need much less lubrication for the same application. Much harder than steel and better thermal charactaristics. The kart guys have been using them for awhile now as well.

 

[gasgasman]

http://www.gmnbt.com/fullceramic.htm?kc=Axwgj2iBQdyTaWBrbyp8YVdBDSTCpKQLZMZEAVu5&OVRAW=ceramic%20bearings&OVKEY=ceramic%20bearing&OVMTC=standard&OVADID=4833099521&OVKWID=49887758021
Benefits of the ceramic (Si3N4) silicon nitride ball bearing:

*Higher Speeds
*Corrosion Resistant
*Higher Temperatures - 800ºC
*Little to No Lubrication Required
*Longer Life/Low Friction & Less Heat
*Non-Magnetic

 

[topari]

Does this mean the two stroke gassers will have ceramic bearings on the crank ?
Is there a significant cost difference ? I just wonder why they haven't used such bearing previously ?

Tom... doing pre-purchase research.

 

[GMP]

For Euro 3 emmissions in '08, running 100:1 premix, I would say most likely.

Berkyboy,

I've seen the ceramic ball bearings, but not an equivalent of the roller bearing on the ignition side. Do they use an exact ceramic replacement or are they back to a ball bearing on the ignition side? If so, same case bore dimmension?