bob's book

[yamahansolo]

i just finished bob's book a few days ago and it was amazing!!!!! he was quite a character!

just one question though. did anyone else read the two articles in the back of the book?

they got the 78 model going 11.7 in the 1/4 and then they go on in the next article to have the special run a 12.2 i think, and it says the standard was just a little slower than the special so that could be a 12.5 or so???? but my questions is wasn't the 79 identical to the 78. if so was this just a ploy by yamaha to sell the special because it was slower? i would think if the jets were the same the cams were the same and the weight was the same then the two standards would be the same speed.... any thoughts on this?????

thanks!!!

[tarzan]

I read his book about a month ago.It was an interesting read.He must of had a castiron butt!I read the extra sections too.I dont remember what the reasoning was that would make either bike faster though.

[Mississippi]

The carbs had leaner jetting (EPA) and I think they changed cam timing in 79 making these bikes a little slower than the 78 XS1100E. The magazine articles on the 79's all talked about them being a bit slower than the 78 model.

[yamahansolo]

i did a search and founbd the only difference was the timing plate. it said the 78 would have 5 more *'s of movement. and a couple of people switched there 79 plates for 78's... i wonder how much they go for on ebay?

[Mississippi]

The Specials had the 31 degree advance but the 79 XS1100F still had the 36 degree advance system. With the same ignition advance the "F" was still slower than the 78E. The January 79 Cycle magazine XS1100 Special road test article states "The carburetor adjustments have taken only a modest toll. Last year's Eleven was an 11.82-115.38 quarter miler; this years Standard version produces a 12.06 ET, while the Special is an 11.93 runner. The SF is a tenth second quicker for three reasons; it's 13 pounds lighter, it's 130/90-16 Bridgestone tire hooks up better and it effectively has a tighter overall gear ratio."

[xs11lover]

I've owned a 79,80,81 specials and a 78e standard. The 78 was the fastest of the bunch. Wouldn't the taller back tire have a little to do with top speed? I've been told the 78 carbs were the fastest, or less emitions tampered.
Another thing..if you just read Bob's book, what was his son's name? I just picked up a tricked out 79xs 1200 and the owner that did/had all the work done to it was Andy Jones..????

[tarzan]

I'll have to check but I think his one sons name was maybe mark?I say "was" as he died years ago.He had three kids.I'll try to find the other two names.

[TopCatGr58]

Hey Lover,

There's faster, as in top speed, and then there's quicker as in 1/4 mile times. Due to the smaller 16" of the 79SF, it was able to use the upper rpm power band a little better to turn the faster 1/4 mile time which kept it similar to the 78E, but it won't run as FAST top end for the same reason.
T.C.

[yamahansolo]

his son's name was mark and he was killed in the 80's during a race. but the article i am talking about states the 79 special ran a 12.2 not an 11.9 it is in the back of the book. and so if the carbs are tweaked on the 79 standard won't it be the same as the 78 if the timing is the same?

[yamahansolo]

http://www.xs11.com/forum/showthread.php?t=73

according to this the carbs only difference from the 78-79 are the pilot and start jet. but another thread in the faq shows the 78-79 carbs are identical except for the jetting. it says the 80-newer has different parts. so if you switched the jets out in a stocl 79 to equal the 78 it would be the same correct? plus if it's been rejetted it should take care of any losses that the factory tried to create. as i stated earlier in the thread all this was pertaining to the articles in bob's book. it quoted an 11.73 78 model time and a 12.2 for the 79 special. that's half a second and as someone pointed out the special is lighter than the standard so the 79 special is a little lighter and still half a sec slower according to this article. it just seems odd to me???