991 or 998?

[scubadown]

I have the 2013 ST-L. The book says it has a 991 Rotax. However it seems almost all references to this motor mention 998. Did it change in 2014 to 998? Why did they add only 7 cubic centimeters? Were there other differences other than displacement?

Thanks

 

[ARtraveler]

:welcome: The answer is Yes. Early v-twins were 990 configuration, a couple years later and they talked about 998's. I don't remember the actual mechanical differences--but you have come to the right place get it answered.

opcorn:opcorn:opcorn:

 

[pegasus1300]

Yes it is very confusing. The 991 is the model of the engine. 998 is the actual physical size or displacement of the engine in cubic centimeters. There is also a model 990. I don't know what the difference in the 2 engines is.

 

[Chupaca]

Not sure...

I do know that the 990 and 991 is the series and not the displacement. The earlier models had 106 hp up to the 2012 model RS, RSS, GS. They later tuned it down to 100hp 2013 thru it's demise. They are all 998 cc...:thumbup:

 

[4 MARIE]

whew, now I can sleep tonight with only visions of a goofy Korean in my dreams.

 

[SilverFox1]

I always thought it was a model 990 with 998 cc's. Could it be that the 991 model was used in the Aprilia?
SilverFox

 

[pegasus1300]

I always thought it was a model 990 with 998 cc's. Could it be that the 991 model was used in the Aprilia?
SilverFox

they were both used in the Spyder and both were 998CC. I forget what the difference between a 990 and a 991 series.

 

[SpyderAnn01]

they were both used in the Spyder and both were 998CC. I forget what the difference between a 990 and a 991 series.

The difference is 1.

 

[pegasus1300]

The difference is 1.

:roflblack::roflblack::roflblack: 1 what?

 

[WilderThomas]

Engine Displacement

I have the 2013 ST-L. The book says it has a 991 Rotax. However it seems almost all references to this motor mention 998. Did it change in 2014 to 998? Why did they add only 7 cubic centimeters? Were there other differences other than displacement?

Thanks

Not that it matters in the grand scheme of things, but I have a 2012 Can Am Spyder RT-S, with an engine displacement of 998cc, with 100hp. The displacement increased to 1330cc in 2014, with an additional 15hp. The engine went from a two, to three cylinder, which I understand is quieter, smoother, with more torque, and noticeably better gas mileage.

 

[Bob Denman]

The two Vee-Twin engines are the 990, and 991 series.
BOTH are 998cc displacement!
The 990s were first used in the GS/RS bikes. They made 106 hp., and 77 ft/lbs of torque.
The 991 series was introduced in 2010, as the engine for the new RT model. It was tuned for 100 hp, and 80 ft/lbs of torque.

The 991s got throttle by wire. (The older 990s were throttle by cable) This allowed the RTs to have electronic cruise control as an OEM feature.
In 2013: the 990s were phased out, and the 991 was used across the entire line-up...

... Until the 1330cc 1403 series triple arrived!

 

[billybovine]

Bob is correct. I would like to add. The reason for the change was for the RT in 2010. A wider, flatter torque curve with power coming on at lower RPM gives better drivability for a touring model.

The compression was increased on the 991 thus requiring 91 octane fuel where the 990 used regular gas.

 

[Bob Denman]

Thanks, Billy! :thumbup:

I didn't go into all of the details about the revised powerbands, or how it was achieved... pps:
The 991 moved the power and torque peaks just about 750 or so rpm down the powerband. This was done to accommodate the heavier loads that the RT would be bringing to the table.
The compression ratio went from 10.8:1 in the 990s, to 12.2:1 in the 991s. THIS is why there was a need to switch to a higher octane fuel.
(The 1403 puts a 12:1 squeeze on things...)

 

[Richardv]

991 also has....

Thanks, Billy! :thumbup:

I didn't go into all of the details about the revised powerbands, or how it was achieved... pps:
The 991 moved the power and torque peaks just about 750 or so rpm down the powerband. This was done to accommodate the heavier loads that the RT would be bringing to the table.
The compression ratio went from 10.8:1 in the 990s, to 12.2:1 in the 991s. THIS is why there was a need to switch to a higher octane fuel.
(The 1403 puts a 12:1 squeeze on things...)

The 991 also has the "new and improved" .... separate catalytic converter......

 

[scubadown]

Great info, thanks. What octane do you guys use. Do you use the ethanol blend (10%)?

 

[pegasus1300]

Great info, thanks. What octane do you guys use. Do you use the ethanol blend (10%)?

in the 991 series,998 cc I use 91 Octane. Since out here blended is almost all you can get that is what I use. There are a few stations that have pure fuel at 88 Octane and I use those when I find one. I don't notice any difference in how the :spyder2: feels and there is no difference in mpg for me.

 

[Bob Denman]

I always ran 93 octane in my 2010 RT. We don't have a lot of chances to buy fuel up here that doesn't have 10% ethanol mixed in with it. It's not that it'll damage the Spyder's fuel system: it's that it decreases the fuel mileage. :banghead:

 

[ARtraveler]

The two Vee-Twin engines are the 990, and 991 series.
BOTH are 998cc displacement!
The 990s were first used in the GS/RS bikes. They made 106 hp., and 77 ft/lbs of torque.
The 991 series was introduced in 2010, as the engine for the new RT model. It was tuned for 100 hp, and 80 ft/lbs of torque.

The 991s got throttle by wire. (The older 990s were throttle by cable) This allowed the RTs to have electronic cruise control as an OEM feature.
In 2013: the 990s were phased out, and the 991 was used across the entire line-up...

... Until the 1330cc 1403 series triple arrived!

Now that I can read a good explanation, I would say that Bob is right on. Glad to see the information put up for all of us. Did you have this stuff in your head, or did you have to do a little research? :bowdown::bowdown: :firstplace::firstplace:

 

[Bob Denman]

pps: I'm ashamed to admit that it was in my head... pps:
A vessel filled with only the most impractical knowledge! :banghead:

 

[ARtraveler]

Great info, thanks. What octane do you guys use. Do you use the ethanol blend (10%)?

RE: Octane: There are many threads about it and the reading is mostly interesting. I have been a :ani29: owner since they first came out. See my signature below if interested.

Since day one, I have always put the highest octane available in my rides. Here, the choices are usually 87, 89, and 90. We do not have ethanol added to our gas.

If I get into remote areas, the choices are usually 87 octane, "mystery gas." Have used it out of necessity a few times. My :spyder2:'s "seemed" to run a bit "less frisky" on the low octane stuff. I would usually re-top the tank ASAP. Might be psychological--but it does not matter. That's my story, and I'm stickin to it. :yes: