93 ST1100 odd questions- new owner

Joined
Apr 30, 2008
Messages
4
Location
austin,tx.
Got this 93 ST1100 about a week ago. Has 22,000 miles. Ordered a honda service manual today. Since it is going to take 10 days to get here, maybe you techies could tell me:

1) Which way does the engine rotate as viewed from the front?
2) How are the cylinders numbered?
3) What is the firing order?
I was interested in this because the neat sound these V4 engines make
is obviously not from evenly spaced firings.
 
Order the Clymer manual right away.

I ordered factory manual for my '93, and while waiting, borrowed a friends factory manual. Started bleeding brake and clutch fluids, and the factory manual was fairly useless and left me with a ton of questions. The factory manual likes to say, "refer to general Honda service manual", which you don't have. Couple other maintenance items, same thing.

When I saw how many pages the Clymer had, I ordered one of them as well. It arrived in 1 day, way before the factory manual. I never touched the factory manual again. Clymer blows it away in every aspect. Heck, it even has full detailed step by step instructions on upgrading the alternator from 28 amps to 40 amps. Another comparison is the clutch fluid section. Something like 2 pages and 2 diagrams in factory manual, while Clymer has something like 12 pages and 28 photos (I forget exact numbers), both manuals relating to same clutch fluid area. Try to find that little metal flow restriction thing that goes into master cylinders. Not found in factory manual. Clymer clearly shows where it goes. The there are the full true color wiring diagrams.. I could go on and on. Stop reading this and get a Clymer right now.

This is what you need to get:
http://www.themotorbookstore.com/honstpaneur1.html
 
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There are two common ways to build a V4 crank, one is described as a 360 degree and the other a 180 degree crank. The ST1100 (and 1300) have 360 degree cranks. The Yamaha V-Max and some years of the Honda VFR had 180 cranks.

The best way to understand this is to consider only one cylinder bank at a time, either the left or right side. If you had the cylinder head removed and turned the crankshaft, you would see both of the pistons rising and falling together. Their compression and exhaust strokes are 180 degrees out of phase however. As both pistons rise toward TDC, one cylinder is on it's compression stroke and the adjacent one is on its exhaust. On the next rotation the relationship is reversed. The same thing is going on in the other bank, but it is 90 degrees out of phase with the first which fills in the 90 and 270 degree firing points.

The 360 degree design allows for perfectly even firing, which has advantages for intake and exhaust tuning/plumbing, but produces a relatively dull droning sound, that doesn't change much with RPM. A 180 degree crank V4 will have a more obvious change in exhaust tone as revs rise and fall. Some folks think this sounds better, as the human ear seems to be fond of more irregular exhaust beats (how else to explain Harleys?). I actually believe that Honda and Yamaha used the 180 design specifically for it's sound quality. While street going VFR were using the 180 design, Honda went with the 360 crank for it's RC30 and RC45 superbikes.

In MotoGP they are doing some things outside of the conventional 180 or 360 degree designs with V4s (Ducati, Suzuki and Honda) in attempting to improve traction and throttle response - but that's a whole 'nother discussion.

Lastly it's interesting to note that the ST1300 engine rotates the opposite direction to the ST1100 and the cylinder numbering is reversed with 1 & 3 on the left side while 2 & 4 are on the right.
 
Quote by wjbertrand
Lastly it's interesting to note that the ST1300 engine rotates the opposite direction to the ST1100 and the cylinder numbering is reversed with 1 & 3 on the left side while 2 & 4 are on the right.
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It is funny, isn't it, Jeff. After hitting perfection Honda had to mess with stuff:)

I had a v-4 Yammie with irregular firing. Yamaha listed theirs with 720? degrees of crank and it was something like 70?, 270?, 430? and 630?. That isn't quiet right, but the idea is there. I liked the sound much better than the ST. Was worth tweaking the exhaust system.

Course the Yammie sat 90? "off", transverse. Did it for smoothness, I am told. Turn the vibration 90? from the wheel plane or some such. Made some service way easier, some way worse (can you say back pair?).

I think I heard a story once, that the ST 1100 rotated clockwise (with counter rotating alternator and transmission to minimize vibration and drive shaft torque. You suppose that is why Honda went to CCW on the ST1300? Found it didn't make a darn bit of difference?
 
Wow guys, thanks for the fast and super informative responses. While I am not a great mechanic, I really like to know whats going on down in the engine room. Talked me into getting a clymers. Having owned several japanese I4 sport and standard bikes over the last 8 yrs, asking such tech questions on those boards would often get some weird answers indicating a lack of basic knowledge of 4-stroke engines. Your answers are smart and written understandably, not easy to do with technical subjects.
 
Used my day off to ride the st1100 to the tire store where I work. Took off
a pile of plastic and the rear wheel. Cleaned the splines, they were well greased with I don't know what but there was plenty of it. The splines were perfect, put some moly60 on'em. Did not replace any o-rings Put new brake pads after cleaning the pistons with brake fluid. Pulled every electrical connector and ground I could find. All were clean except for two pins in the reg/rect were slightly crusty. Teased those 2 pins out of the female plug, cleaned them and the pins in the rr, and put a dab of dielectric grease in evrything. Then put a voltmeter to the battery before re-connecting it, had 13.15 volts, indicating fully charged I think. Started it up, meter read 13.0 at 900rpm, 14.4 at 1100, and 14.6 to 14.67 from 2000 to 5000 rpm. Ran it at 2000-3000revs about 10 minutes to see the volts with fan, hi beam and brake lights adding their load, almost no change above 1500 revs. Wow, does that rr get hot or what! Too hot to press your fingers to and this from a guy used to handling sizzling hot lugnuts I have never had a bike this old so I am keen to look at this stuff. One of our auto techs said the wire/connector condition looked lots better than a 15 year old car would look,but then few cars this old have only 22,000 miles. Probably should pull the upper cowling and check those wires. All this stuff I did today were based on posts and suggestions from this board. Had fun doing this and feel better about and closer to this old bike.
 
Heeey. That's a great start.

Sounds to me like you are on the run. Now go put some milage on the old sister so she doesn't feel neglected.

Your alternator numbers are good. I replaced mine at about 75,000mi, if that will help reassure you...It will have to be done some day, but the cost isn't that much ($525.00) for parts, and the help and instruction around these sites is unbelivable. Makes the swap pretty darn easy...
 
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