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wishful thinking, look what is happening with other Japanese brands...
cost saving cuts all over the place. That's the only reason I didn't buy new Africa Twin. I knew it's gonna happen first because of that horrible tsunami
and then emission BS...
The AT is a premium Japanese ADV machine and they are selling quite a few of them, so what are the issues and saving cuts you speak of? :confused:
 

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The AT is a premium Japanese ADV machine and they are selling quite a few of them, so what are the issues and saving cuts you speak of? :confused:
oh boy :) that would be long list, if you were on the market for new AT like I was you would know that. Do quick search on advrider or at forums if you're interested.

BTW if this is suppose to be premium Japanese adv bike now I'd rather buy KTM or BMW :)
 

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Depends

Flame speed is pretty constant in a combustion chamber. In a physically large combustion chamber it takes longer to complete combustion. Such a chamber is usually more susceptible to detonation as well. So you have conflicting needs to retarded timing to avoid detonation, but a need to advance it to allow more complete combustion. And higher-octane fuels are generally unavailable. A second ignition course can reduce the flame travel time, and perhaps increase turbulence which may increase flame travel speed.

Aircraft engines operate in prime detonation territory, low revs (2700 RPM) and high loads. Most were also air-cooled. Traditionally high-octane leaded fuel was used to provide a margin of safety. Unfortunately the lead tends to accumulate on spark plugs and foul them, especially if the pilot doesn't lean the mixture when appropriate.

Well-designed combustion chambers usually try to confine the air-fuel mix to a relatively small volume at top dead center, minimizing the travel distance.

If you add a plug, be interesting to put a knock sensor on the head and fiddle the timing. Might get significantly more power, assuming the other systems are up to it. I believe some manufacturers also fired the plugs at different times, an additional area of experimentation.

Evidently Bosch is experimenting with a microwave ignition source that ignites the entire charge simultaneously. Seems to me that would be very similar to detonation, so presumably they'll be experimenting with very lean-burn engines, or perhaps sequential fuel injection.
 

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Evidently Bosch is experimenting with a microwave ignition source that ignites the entire charge simultaneously. Seems to me that would be very similar to detonation, so presumably they'll be experimenting with very lean-burn engines, or perhaps sequential fuel injection.
Igniting the whole charge simultaneously would essentially eliminate the possibility of detonation. Remember, detonation is not a normal combustion process, but an extremely rapid "explosion" like process (thus the name "detonation"). If the whole charge is simultaneously ignited there will be no chance for the unstable compounds to form which cause detonation.

Detonation is also not the result of multiple flame fronts reaching each other. If it was, adding a second spark plug would cause detonation, not help to avoid it. It is the detonation itself which creates shock waves and high pressure spikes during the combustion process.
 

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Discussion Starter #26
the reason Expansion chambers work so well on 2 stroke engines is the power pulse wave that bounces back to the cylinder which
helps fill the cylinder with a fresh charge on the next cycle. Evacuation - fill - Evacuation - fill These pulses help the engine develope
more power without any changes anywhere else. A rather novel idea.
 

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Detonation

Detonation is the result of radiated heat igniting the fuel mixture ahead from the flame front, rather than the orderly progression of combustion. So rather than a smooth increase in cylinder pressure, you get big spikes, which are hard on bearings and other stress-carrying parts. The extreme turbulence also scrubs the thin stagnant layer of insulating gas off the top of the piston, exposing the aluminum to temps it can't handle.

Two flame fronts, assuming they are 'orderly', may reduce the chances of detonation, so long as they reduce the overall time to complete combustion. That's the point of dual-plug heads.

The problem with the microwave ignition as I see it is that it would act very similar to detonation. Rather than an orderly burn that smoothly increases pressures, all the fuel burning all at once would be more like an explosion. Very hard on bearings and parts. Possibly a pre-chamber design with metered flow to the main combustion chamber would work. Or, as I said, sequential fuel injection. Inject a little fuel, burn it, inject a little more, etc.
 

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my 1983 Nissan pickup truck had 2 plugs/cylinder, also had 2 coils, weird distributor cap, looked like it was for a v8 instead of 4 banger, except that it had 2 coil wire inputs
 

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oh boy :) that would be long list, if you were on the market for new AT like I was you would know that. Do quick search on advrider or at forums if you're interested.

BTW if this is suppose to be premium Japanese adv bike now I'd rather buy KTM or BMW :)
Nah I am very familiar with the "issues", most certainly no worse than the V-Stroms if we were being honest. ADVrider is full of a bunch of whiny crybabies IMHO, big reason why I rarely visit there any more. The AT would be bar none my first choice for an ADV machine at this point, but loathe the tube wheels and having no factory cruise control yet.
 

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^
My Son still had his 2004 DL 650 when I bought my new 2012 DL 650. I weigh more than him by quite a few pounds. The 2012 would pull away from the 2004 anywhere at any time. And usually averaged about 1-2 mpg better on trips.

Horsepower isn't everything. I think some places had the peak horsepower at a lower number on the 2012 and up DL 650. But average HP under the curve was very much in favor of the 2012 and newer engines. Where his 2004 didn't want to be run under 4000, the 2012 was quite happy running around town at 3000 rpm.
 

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The AT is a premium Japanese ADV machine and they are selling quite a few of them, so what are the issues and saving cuts you speak of? :confused:
Actually, the AT is not that "premium". Yes, there are ADVrider cry babies. But Honda screwed the pooch with the front suspension. Lots of riders are having issues with it early on and Honda is denying coverage. That is the big problem. Most of the serious AT owners are dumping significant money into the front forks.

Little problems....cheap switch gear, rusting spokes/fasteners etc. The AT has a great design, but the bean counters had too much time with it before it was completed. They are selling cheap on the used market....like all the rest are.
 

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Actually, the AT is not that "premium". Yes, there are ADVrider cry babies. But Honda screwed the pooch with the front suspension. Lots of riders are having issues with it early on and Honda is denying coverage. That is the big problem. Most of the serious AT owners are dumping significant money into the front forks.

Little problems....cheap switch gear, rusting spokes/fasteners etc. The AT has a great design, but the bean counters had too much time with it before it was completed. They are selling cheap on the used market....like all the rest are.
Yeah I've heard of those things, seems the suspension issue is hit or miss.......is it resolved now? The T7 better be PERFECT for as long as Yamaha has had to screw around with our minds and that bike, and I hope they make a premium edition of that model, oh and PLEASE update the Super 10 Yamaha and have it lose some weight but gain more HP!!!! :fineprint:
 

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Actually, the AT is not that "premium". Yes, there are ADVrider cry babies. But Honda screwed the pooch with the front suspension. Lots of riders are having issues with it early on and Honda is denying coverage. That is the big problem. Most of the serious AT owners are dumping significant money into the front forks.

Little problems....cheap switch gear, rusting spokes/fasteners etc. The AT has a great design, but the bean counters had too much time with it before it was completed. They are selling cheap on the used market....like all the rest are.
exactly right, honda quality is a mit already and history. I canceled my order twice after I've seen on my own eyes what's going on. AT is definitely best looking adventure bike but that's about it.
 

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Yeah I've heard of those things, seems the suspension issue is hit or miss.......is it resolved now? The T7 better be PERFECT for as long as Yamaha has had to screw around with our minds and that bike, and I hope they make a premium edition of that model, oh and PLEASE update the Super 10 Yamaha and have it lose some weight but gain more HP!!!! :fineprint:
The forks have a new coating now. The new higher spec model has longer travel version of same forks. Owners are doing lots of fuxxoring with building new forks out of a combo of the standard and upper spec model parts. Some owners are just going straight to Ohlins.

This is a pervasive issue for many who ride the AT hard. It effects street riders too, but takes longer. The Showa forks used on the AT are rehashed from years ago.

I am no expert, just following the soap opera since I almost bought an AT. I think the T700 will be better since I believe it uses KYB equipment and it is a little lighter.
 

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I don't think we pay enough attention to spark plugs.

My dad was a automotive parts wholesaler and a huge part of his business was Champion Spark Plugs.

I caught up with my dad for lunch one day and he had invited one of the big wigs from Champion Australia.

The conversation soon turned to cars and bikes, he quickly told me I could gain 8hp at the rear wheels of my car if I reduced the gap on my plugs from the recommended .059" to .057" but the motor would not be as smooth in the lower RPM's.

I then asked about my 1997 KDX200, I had spent a lot of time playing with the carburettor jets but I could never get it perfect, if it was crisp and clean down low it would be fluffy up top or if I got it crisp up top it would be fluffy down low, he asked what plug I had in there, NGK B8ES.


A few days later I got some champion plugs in the mail, N2g & N3g (gold), the performance difference was outstanding, no more fluff just crisp and clean at all throttle openings.

After that I got my dad to get me a few boxes of them, I ended up owning every N2g & N3g in Australia at the time, every time one of my mates or even strangers fouled a plug I would fit one of my special plugs as they came to be known, they never fouled and it turned out when my mates sold their bikes they would keep the spark plug and move it to their new bikes.

My dad had a customer that raced go-carts, he always ran in the middle of the pack until I suggested he try a N3g plug, he started to win races and was so impressed with the plug he scared the outside of the plug so know body at a race meeting could tell what plug he was running.


I still keep some N3g's in the shed but I now import them from the UK.


Until that first lunch I never gave spark plugs much thought.
 

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If only this twin plug technology was introduced back in the late 60's, for our two strokes, I wouldn't have to had to clean / thrown away so many spark plugs. Synthetic oil in a two stroke was also a marvelous discovery for spark plug life. LOL
 

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I don't think we pay enough attention to spark plugs.

My dad was a automotive parts wholesaler and a huge part of his business was Champion Spark Plugs.

I caught up with my dad for lunch one day and he had invited one of the big wigs from Champion Australia.

The conversation soon turned to cars and bikes, he quickly told me I could gain 8hp at the rear wheels of my car if I reduced the gap on my plugs from the recommended .059" to .057" but the motor would not be as smooth in the lower RPM's.

I then asked about my 1997 KDX200, I had spent a lot of time playing with the carburettor jets but I could never get it perfect, if it was crisp and clean down low it would be fluffy up top or if I got it crisp up top it would be fluffy down low, he asked what plug I had in there, NGK B8ES.


A few days later I got some champion plugs in the mail, N2g & N3g (gold), the performance difference was outstanding, no more fluff just crisp and clean at all throttle openings.

After that I got my dad to get me a few boxes of them, I ended up owning every N2g & N3g in Australia at the time, every time one of my mates or even strangers fouled a plug I would fit one of my special plugs as they came to be known, they never fouled and it turned out when my mates sold their bikes they would keep the spark plug and move it to their new bikes.

My dad had a customer that raced go-carts, he always ran in the middle of the pack until I suggested he try a N3g plug, he started to win races and was so impressed with the plug he scared the outside of the plug so know body at a race meeting could tell what plug he was running.


I still keep some N3g's in the shed but I now import them from the UK.


Until that first lunch I never gave spark plugs much thought.
I ran B8ES in just about all my bikes back then. Never a problem. I did a seminar by a Champion rep way back in the early 80s. He told me the reason their spk plugs had gotten better was they copied NGK. (True story). Possibly that "Special" spark plug was fixing a jetting issue?
 

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It didn't just fix my jetting it fixed everybody's.

As I said I spent hours with different jets and needles trying for perfection, I was unable to get that with the NGK plugs but it was quick and easy with the Champion Gold.
 

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Discussion Starter #40
I had my share of fouled 2 stroke plugs in all the boat motors and older jet ski's we had over the years. Then I purchased
a brand new 2008 Yamaha VX 110 4 stroke. Jet ski ! Oh baby, It was nice. No more of that fiddling with plugs, lean and rich
Things were so much easier. You could stand up and ride it like a dirt bike on the water. What fun.

The ski before that one was a 1992 Yamaha VXR 701 it was a 2 cylinder 2 stroke and it was a real bitch to try to keep it
from loosing prime and cutting out. It seemed like no mater how tight you put the fuel line clamps on, it would draw air.
You could tell right away because the top speed would sink from 45 mph down to about 30 mph. We never went out in it without
at least 2 or 3 pairs of plugs at the ready. NGK's
 
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