Redline

[Ivan]

What is redline on these engines? My 81 special has a white arc from 8500 on up.

In aircraft speak, the "white arc" refers to max safe flap deployment speed. I am pretty sure this tach didn't come from a cessna.

[Rasputin]

My 78E shows redline at 8500. My 79SF shows white at 8500, used to be red but the sun bleached it.

[Pat Kelly]

semi-hijack

The redline for the stock XS1100 is 8,500 RPM.
Generally, the larger the displacement, the lower the redline. The XS750 has a redline of 9,500 RPM. My 78 Honda CB400TII had a 12,500 RPM redline.
My LG has the 1196 (1200) big-bore kit. Should the redline RPM be lower?
FWIW I have taken it to a tad over 9,000 RPM without issue.

[XSPastor]

My 81 special has a white arc from 8500 on up.

Your speedo has been bleached by the sun. That white line used to be red if it's a 1981 speedo. I think the 1980's were white though... With the age of our bikes, it's also possible that you don't have the original speedo.

[Ivan]

Originally posted by XSPastor


Your speedo has been bleached by the sun. That white line used to be red if it's a 1981 speedo. I think the 1980's were white though... With the age of our bikes, it's also possible that you don't have the original speedo.

The speedo isn't original. Not sure about the tach though.

[81xsproject]

I have an 80's bike and redline at 8500 is just that, red. My old one was sun bleached too, but still pinkish.

[TopCatGr58]

Re: semi-hijack

Originally posted by Pat Kelly
The redline for the stock XS1100 is 8,500 RPM.
Generally, the larger the displacement, the lower the redline. The XS750 has a redline of 9,500 RPM. My 78 Honda CB400TII had a 12,500 RPM redline.
My LG has the 1196 (1200) big-bore kit. Should the redline RPM be lower?
FWIW I have taken it to a tad over 9,000 RPM without issue.

Hey Pat,

I didn't bother weighing my big bore kit pistons to compare them with the OEM's, but they are larger diameter. But I would think that Wiseco would have engineered them to probably be the same or less weight than OEM so that the inertia forces would be similar which should retain the same rpm redline.

I take mine to 8500 every so often and no problems! YMMV.
T.C.

[Ivan]

I take mine up there every so often as well. I was just wondering if it had a yellow portion then a red portion, like a lot of other vehicles.

I wish it were easier to take apart, I would redo the face of the tach to make it look spiffy and new again.

[Tusler]

If you are taking a 28+ year old bike and motor past 8500 rpm you ought to be ashamed of your self!

[oseaghdha]

Re: semi-hijack

Originally posted by Pat Kelly
The redline for the stock XS1100 is 8,500 RPM.
Generally, the larger the displacement, the lower the redline. The XS750 has a redline of 9,500 RPM. My 78 Honda CB400TII had a 12,500 RPM redline.
My LG has the 1196 (1200) big-bore kit. Should the redline RPM be lower?
FWIW I have taken it to a tad over 9,000 RPM without issue.

Redline is, generally speaking, a function of piston speed; which is determined by stroke.

The high winders usually have a short stroke crank. Then, you have to start looking at the valve train and valve float.

[Ivan]

Originally posted by Tusler
If you are taking a 28+ year old bike and motor past 8500 rpm you ought to be ashamed of your self!

Well, when I am trying to smoke some big twins and she misses second........

[subike]

With fresh oil, ajusted cam followers, clean air filter, tuned carbs and big bore exhaust 9000 rpm is no worries.
Have done it often on hills pulling out of the tight ones.
But you got to keep them tuned well if you want then to live at that engine speed.
Makes for a very nice top end speed, 8750 rpm in 5th

[79XS11F]

Hmmm dangerous post but here it is ... red line for me is not on the tack.. it's in the seat of my pants. When ever I crank her with the intension of maximum speed, I switch gears when the engine stops pulling strongly. Sometime that's above 8.5 and sometimes it under 8.5 depending on the engines temperature. Failing to change gears when the engine is no longer pulling is asking for trouble. With my 1179 kit she pulls strong past 9 K. I take her there from time to time.
Rob

[Dan Hodges]

Wailing Limit

Originally posted by TopCatGr58


Hey Pat,

I didn't bother weighing my big bore kit pistons to compare them with the OEM's, but they are larger diameter. But I would think that Wiseco would have engineered them to probably be the same or less weight than OEM so that the inertia forces would be similar which should retain the same rpm redline.

I take mine to 8500 every so often and no problems! YMMV.
T.C.

Pardon me for jumping in but I have a couple tidbits of info. The stock pistons weigh 210.7 grams and the stock pin weighs 60 grams. The current Wiseco 74 mm pistons weigh 193 grms. and the pins weigh 57 grams. A good motor with fresh stock valve springs will turn 9,000 rpm safely however the power band of a stock motor signs off at somewhere between 7500 and 8,000 rpm and so taking it to anything more than that is a waste of parts. Stiffer after market valve springs from Kibble-White will allow more rpm but with the stock cam/cam's the power still dies after 8,000 rpm. Even with a set of cams sporting 20 degrees more duration than the stock 81 cams and a 4 into 1 header with a 2.5 inch exhaust core my motor leveled out at 8,500 rpm on the dyno and at 9,000 was still level but it was starting to fall off and subsequently I didn't go any higher than 9,000. The Eleven has it's adjustment shims on top of the bucket and if you over wind the motor and float a valve the shim/shims are prone to pop out and should this happen you have lost the motor. You can convert these things to shim under bucket like the Kawasaki's and some Susuki's but it's expensive but would be necessary if you were going to use a cam with much over .400 valve lift. The XS has a 2.7 inch stroke which isn't that bad and the crank and rods are excellent pieces even though better rod bolts are available and the oil pump can be tweaked for more pressure if you needed it for racing purposes. Titanium valves from K-W and a set of cams with something in the neighborhood of 265 degrees at .040 lift and .438 of valve lift would complete your 10,000 rpm killer motor. However if your motor is stock, anything over 8,000 rpm is just whistling in the wind and hurting parts. Happy wailing!

[79XS11F]

Re: Wailing Limit

Originally posted by Dan Hodges
Pardon me for jumping in but I have a couple tidbits of info. The stock pistons weigh 210.7 grams and the stock pin weighs 60 grams. The current Wiseco 74 mm pistons weigh 193 grms. and the pins weigh 57 grams. A good motor with fresh stock valve springs will turn 9,000 rpm safely however the power band of a stock motor signs off at somewhere between 7500 and 8,000 rpm and so taking it to anything more than that is a waste of parts. Stiffer after market valve springs from Kibble-White will allow more rpm but with the stock cam/cam's the power still dies after 8,000 rpm. Even with a set of cams sporting 20 degrees more duration than the stock 81 cams and a 4 into 1 header with a 2.5 inch exhaust core my motor leveled out at 8,500 rpm on the dyno and at 9,000 was still level but it was starting to fall off and subsequently I didn't go any higher than 9,000. The Eleven has it's adjustment shims on top of the bucket and if you over wind the motor and float a valve the shim/shims are prone to pop out and should this happen you have lost the motor. You can convert these things to shim under bucket like the Kawasaki's and some Susuki's but it's expensive but would be necessary if you were going to use a cam with much over .400 valve lift. The XS has a 2.7 inch stroke which isn't that bad and the crank and rods are excellent pieces even though better rod bolts are available and the oil pump can be tweaked for more pressure if you needed it for racing purposes. Titanium valves from K-W and a set of cams with something in the neighborhood of 265 degrees at .040 lift and .438 of valve lift would complete your 10,000 rpm killer motor. However if your motor is stock, anything over 8,000 rpm is just whistling in the wind and hurting parts. Happy wailing!

Valve float is a concern for me and these 11s are know to float their valves but i can't find any after market springs to correct this issue. Dan ... do you by chance have a link to a site that sells after market valve springs for the 1100?
Rob