XT1200Z Engine Comments

[Rick]

Hi guys,

I compared the R1200GS to the XT1200Z and noticed a couple of things. This link on the ADVRider forum http://www.advrider.com/forums/showpost.php?p=13410775 shows the relative power curves of several models. It is the only dyno chart I have seem comparing these 2 models. The main differences in these engines aside from the air cooling vs liquid cooling is the bore and stroke and compression ratio. The BMW has a larger bore and shorter stroke but a higher compression ratio. Typically, that would produce a power characteristic of more upper end power with some trade off down low. The Yamaha's +6.5 mm stroke advantage is a huge difference, and it has a 29 cc advantage too. Its lower 1.0 point compression ratio means it will be mellower but that crank stroke should make it really powerful down low. When I look at the dyno chart above it doesn't seem right. Does anyone else have a dyno chart of this engine? Given that the Yamaha is liquid cooled it seems like it could handle a higher compression ratio. Maybe a set of 12:1 or slightly higher pistons would be in order.

 

[20valves]

Yamaha may have given it lower compression so it could tolerate a bit lower fuel quality as you tour through countries with varying fuel standards. Just a guess...

 

[fjr1300]

Yamaha supplied a US map to all snowmobile techs at a service seminar back in 2000. They had researched the quality of gas and not suprising was the Midwest states had the worst quality (except for the large Metro areas). I was advised for my snowmobile, atv, or motorcycle to shut off fuel and run carbs dry if the unit was going to be parked for more than a week. They would warranty one carb clean only. So at the end of the seasons I drained all fuel from the unit, ran until the engine quit and opened the float drains to make sure all was out.

So, I agree it was probably done for fuel quality. Around where I live its hard to find premium fuel that doesn't have ethanol.

 

[markjenn]

The S10 is generally just in a lower state of tune - lower compression, lower RPM, less oversquare, milder cams, etc. - all the classic stuff to make an engine perform better at lower RPM at the expense of top-end power. Liquid cooling provides additional headroom to tune an engine more aggressively and Yamaha could have taken advantage of this, but they either elected not to or for some reason the engine is under performing. The S10 does seem to have a flatter torque curve with less lumps than the BMW so perhaps Yamaha prioritized this heavily.

Everything else being equal, the S10's lower state of tune should have translated to a bit more power down low at the expense of power up high, but based on results like this (and they mirror other testers subjective assessments), it didn't work out that way and there could be a lot of factors involved - the 270-deg crank causing non-optimal exhaust tuning (in the Triumph Bonny's, the same engine is produced in 360- and 270-deg cranks configs and the 270-deg engines are down 10% or so on power), emissions and noise constraints, drive train reliability considerations, traction control considerations, cost of production considerations, desire to use lower octane fuel, etc. etc. etc. Bike engines are built to specific performance targets with a lot of complex tradeoffs.

Personally, I think the S10 engine is under-performing slightly from where it should be. Not enough to make me get a GS, but everything being equal, I think Yamaha should have been able to push the S10 for about the same low-end power and another 5-10 ponies on top. I wish they had gone with the 360-deg crank also, but I think they felt they needed to continue the crossplane push even though it is turning into a bit of a boondoggle on the R1. (I think the crossplane will turn out to be like the 5-valve heads that Yamaha and Audi were so hot on initially - a technological dead end.) I view this as a lost opportunity and with a new water-cooled GS expected in the next 18-months with 10 or so more hp, Yamaha will be losing some sales as the power disadvantage goes from minor to significant. When the inevitable head-to-head comparison with the GS occurs in US magazines in a few months and if these results are more or less confirmed for US tuned bikes, you can be sure the Yamaha will lose points on engine power.

None of this says the S10 doesn't have plenty of power for its mission as it does. We're talking degrees of overkill here.

- Mark

 

[pqsqac]

Markjenn awesome write up very detailed thanks for your thoughts. All in all I think the S10 will do it's job and folks looking for this type of bike go into it knowing it won't be the fastest kid on the block but we know the bike will be around for years running strong, Yamaha puts out an excellent product.

 

[RMac]

"Lower state of tune".

I also wonder how this relates to engine reliability and longevity? My gut reaction is to think it would improve longevity, all other things being equal.

 

[rocca]

I think it likely that Yamaha have been deliberately conservative with the state of engine tune, because it's a new design. I expect it'll have a long production life with plenty of development to come.

Regarding the crossplane crank, the R1's engine certainly feels very special with its combination of quick spin-up and huuuge pull from right off the bottom. Quite unlike any other IL4. Sounds fantastic too. There is actually a slight similarity with the XT1200's engine feel on initial throttle opening, but from that point on the R1 just warps space/ time/ reality....

I certainly hope the crossplane doesn't go away: the R1's "problems", if they can be termed such, are more in the area of the chassis because it doesn't steer quite as sweetly out of the box as it might do.

 

[RomKnight]

Want a relaxed engine? Use D-mode T
Want power? D-mode S should take care of if.

People complaining for 10hp... unbelievable. Are there races for large trails that i'm unaware of?

 

[jajpko]

It's a Tim Taylor thing,,, More Power 8)

 

[johnnail]

"Lower state of tune".

I also wonder how this relates to engine reliability and longevity? My gut reaction is to think it would improve longevity, all other things being equal.

What he said

 

[k woo]

I'm fine with a minor "lower state of tune" as long as it does not make the bike anemic. If a little "detuning" helps the engine last longer then I'm all for it, as I plan to put as many hundred thousand miles on my S10 as possible.

 

[Rick]

Have any of you guys noticed that the S10 and the V-Strom have the same bore size, but the S10 has a stroke that is 13.5 mm's longer. This translates into a lot more bottom end power than the V-Strom. The V-Strom has a 11.3:1 compression ratio but I have been unable to get mine to run without detonation on regular gas. There are plenty of engines that have a higher compression ratio than that, that seem to do fine on regular gas though. It all depends on how efficient the cooling system is. The R1200GS is air cooled and has a 12:1 compression ratio. That speaks well for its ability to get rid of heat regardless of which fuel octane it requires. It seems that the new Yamaha is ultra conservative. I'd still like to see a couple more dyno graphs of the S10 engine.

 

[eemsreno]

I'm fine with a minor "lower state of tune" as long as it does not make the bike anemic. If a little "detuning" helps the engine last longer then I'm all for it, as I plan to put as many hundred thousand miles on my S10 as possible.

You read my mind

 

[markjenn]

Regarding the crossplane crank, the R1's engine certainly feels very special with its combination of quick spin-up and huuuge pull from right off the bottom. Quite unlike any other IL4. Sounds fantastic too. There is actually a slight similarity with the XT1200's engine feel on initial throttle opening, but from that point on the R1 just warps space/ time/ reality....

I agree it has a different "feel" and many love the different engine texture, but the R1 has the dubious disctinction of being one of the least powerful liter inline-fours, yet the heaviest, its "pull off the bottom" is nothing special and it has a weak mid-range. The R1 currently is among the bottom dwellers in all the comparison tests. (That doesn'e mean it isn't an incredible bike - I've owned two R- bikes over the years and loved them both.) The proof of the success of the technology will be whether it will be adapted by others or even continued by Yamaha more than a few years. The Japanese are quite paranoid about technical advances and will copy the competition if they think anyone is getting the advantage, but we're not seeing any other player adapt the crossplane. Even Yamaha has said they're not going to use it in the R6.

I know many will disagree with me and say that the 270-deg crank is better because it "hooks up" out of corners, but I personally think Yamaha (and Triumph for that matter) use it mostly because it gives the engine and exhaust note more character - 360-deg parallel twins can be droners with an unpleasant engine sound.

- Mark

 

[RMac]

This will be interesting when all you guys State side finally get your S10's. Will we see a frenzied rush for Power Commanders and aftermarket exhaust systems? At-least a larger percentage interest for power/response enhancement than happens for other bikes in the same class?

A few of the first European reviews out last year were somewhat negative about the S10's engine character describing it as a bit flat, wheezy and dare I say it, boring (someone say "anemic" ?). It remains to be seen whether the "Euro dip" around 4.5k rpm will be present on the US models (to meet noise emission requirements over here). This dip is something that I have commented on in another thread in the technical section and to be honest is the only thing I can personally find to complain about. When 2-up the bike can feel shockingly flat (for a 1200cc) in this rpm range, especially in the first four gears. For the first time in my riding career, I can say that I am potentially in the market for a solution to reduce the dip and give more linear engine response, e.g. after market can, or something else.

To contrast a little, I have test driven the BMW R1200GS on two separate occasions, and last time was a 2010 year model GS. The GS does feel quite a bit snappier than the S10 and the perception of the "Euro-dip" is not there as it is for the S10. Possible that BMW have reduced the perception by providing double torque peaks in this region giving it a feeling of more "character". In any case, for me the decision was not based on engine response alone, but mainly the fact that the GS has a number of attributes that personally do not appeal to me. The bottom line is I felt at home on the S10. Bare in mind that I am a guy coming from a DL650 and never having owned anything larger prior to that.

I don't want to get people concerned about the S10's engine and for me it is the overall package that counts most, but worth pointing out that if you expect bone crushing torque over the entire register you may be a bit dissapointed. With the S10 it is all about the intended use of the concept and most definately not about 1/4 mile times and pulling wheelies.

 

[markjenn]

This will be interesting when all you guys State side finally get your S10's. Will we see a frenzied rush for Power Commanders and aftermarket exhaust systems? At-least a larger percentage interest for power/response enhancement than happens for other bikes in the same class?

There's always a rush for PC's and exhausts. It's what motorcyclists do. But it will be interesting to see if the US S10's are delivered in essentially the same tune as the Euro bikes. I'm betting they will be, but perhaps Yamaha will use this opportunity to refine things and extract a few more ponies.

- Mark

 

[Rick]

I'm not going to put a pipe or any other power enhancing devise on my S10. Pipes sounded so cool to me when I was 20, now, they're just annoying. In this state, loud exhausts will soon be outlawed. Well, they're already outlawed it's just that pretty soon they are going to start enforcing the law. It's really a move to turn down the obnoxious sound of the Harley's. We can thank Arnold for that. Anyway, it doesn't effect me.

I rode my 03 DL1000 for more than 90,000 miles before I added a Power Commander. I got that and a few other things when a guy totaled his bike and sold off his farkles. It does clean up the surging below 4000 rpm's. I hope the new bike doesn't need anything like that to run right.

 

[RMac]

I rode my 03 DL1000 for more than 90,000 miles before I added a Power Commander. I got that and a few other things when a guy totaled his bike and sold off his farkles. It does clean up the surging below 4000 rpm's. I hope the new bike doesn't need anything like that to run right.

No, the S10 certainly doesn't have problems like that. Not that I've noticed at-least. Seems like Suzuki never did sort out the DL1000 engine management from what I've heard (?)

Also, based on many of the answers I got in the other thread where I brought up the 4.5k torque dip many reported that they didn't really notice it or were not bothered by it.

Will be interesting to see if US S10's have same tune as EU when they arrive.

 

[pqsqac]

I agree with this 100% in my younger days you couldn't make the bike loud enough now at 47 I want quiet. The HK pipes I'm running now are way too loud. It's sort of like realizing the volume knob goes to the left as well. ;D

I'm not going to put a pipe or any other power enhancing devise on my S10. Pipes sounded so cool to me when I was 20, now, they're just annoying. In this state, loud exhausts will soon be outlawed. Well, they're already outlawed it's just that pretty soon they are going to start enforcing the law. It's really a move to turn down the obnoxious sound of the Harley's. We can thank Arnold for that. Anyway, it doesn't effect me.

 

[pqsqac]

This is a good thread on the S10 engine I’m learning a lot. I know I'm going to be in for a shock at first coming off a 1800cc V twin with 127 hp and 117.6 ft lbs of torque to a 1200cc will be an adjustment but I'm also leaving behind 760 lbs of curb weight and a 250mm rear tire that handles like a semi in the corners. On top of that I can't haul any gear or very little and my gas mileage is 32-34 mpg with 4.5 gals of petro. Yeah I'm ready to down tune for all the other benefits the S10 offers and I really don't care how fast I get to 70 mph once I’m there the speed is the same no matter what bike you are on.

I think the S10 will suit me just fine for my current needs I’m not buying it for it’s speed but as a good all around and versatile ride. I’m done with changing pipes, adding PC’s, rev limiter eliminators etc. Just my two pennies!