Timing question ...

[trbig]

Thinking about that last post... What I have seen over time is that the exhaust cam tends to retard over time, but the intake cam advances a bit. Having the cams slotted in both directions 5 degrees would make it able to adjust both to the right point.


Tod

[thewiz]

Ernie ..

Far as the 5 to 6K rpm power 'limit' I'm experiencing .... I haven't pushed this bike hard yet in the upper gears. Don't wanna' break something or get stranded. It just feels like it is running out of power at that point. In fact, this one doesn't easily rev up past that 5-6K rpm in neutral. My other XSs don't behave thataway.

Since this motor has never run as good as it should , AND, someone else has s'posed to have been under the cam cover to adjust valves, I thought it prudent to check that out with my own eyes. Doesn't hurt to have a couple of hundred pairs of eyes from the VERY knowledgeable people on this forum checkin' it out right alongside of me either. Thx everyone for your time and contribution. I'm bettin' on the new coils to cure this nasty problem now.

A Clymer manual on XS1100 Fours ... about $25 .... belonging to this forum ... F'in PRICELESS !!

[thewiz]

OK ... well ..

took everything off the timing side down to the crank. Crank dowel in position.

Ray .... the only thing I can see that I COULD FLIP 180 degrees are the pick up coils themselves. Is that what you're saying to do? Looks to me like everything else can go on there only one way ??


I may have found the performance problem though ... if not "THE" problem, it's surely one of 'em The mechanical advance unit doesn't move freely with the reluctor it on. When I twist the reluctor to stretch the springs (advance it), which aren't in great shape either, it just binds up and doesn't return . It was/is so bound up that I don't believe centrifugal force could even spin it out .... less'n it was more rpm than this motor is gonna' do. Looks like the brass bushing that it rides on has a couple tiny marks, possibly from pliers where someone else in the past had tried to get it offa' the crank. Now it took me a about 15 minutes of very careful prying and wiggling with a square shanked screwdriver to get it off the c.shaft without wrecking the front seal or the governer itself. Apparently someone else didn't have that much time .... am I surprised? Nope. One thing for certain, I don't believe that the mech advance unit could have possibly worked. Was just way too bound up. Off to check my parts stash and/or hunt up some crocus or very fine emery cloth.

So do any of you who are not totally bored with this thread yet believe, as I do, that this could be robbing the upper range power and rpm?

[psycoreefer]

It sure could be robbing top end power. Thats why they put an advance on engines is to help produce more power at high RPM's because the fuel needs to start burning sooner. I'd bet thats a least part of your problem.

[TopCatGr58]

Hey Wiz,

I think you have found the golden key!!

The timing advance gets to it's max around 5K rpm, but IF you are not getting any Cent. adv, then it's running severely retarded....no pun intended, and it definitely would NOT have any power even trying to get to 5K rpm, much less past it!!

Once you get it fixed, and moving properly, put a timing light on it with the Vac. adv. disconnected/plugged off and see that it's actually moving when you take it up to the 5k range. Once you have confirmed that you NOW have cent. adv. then take it for a ride....BUT HANG ON!!!! And try to keep the front wheel on the ground!
T.C.

[thewiz]

Thx, Psycho and TC

I think so too. Even better, I have a good mech. advance unit too. So when the coils and wires get in AND I fix a few valve clearances, I think it'll run great. If it runs 90 percent as good as my G, I'll be a happy camper.

[egsols]

Cam timing dots

I was scanning through my haynes manual last night and they have a pic showing how to line up the cam timing marks. I tried to scan it in to show you but my scanner can't pick up the detail. Anywho, the dot, in the manual is about a half dot to the right of the arrow, on the intake cam, just like your pic!!

[TADracer]

Re: Just jump

Originally posted by planedick
I don't know what you're trying to do besides call me a liar.

Would never do that, Sir. I am only participating in a very interesting and active thread based on my own experiences and what has worked for me. Sorry if I have rubbed you the wrong way.

[planedick]

No rubbing

I'm sorry for being so short tempered. Got a sick dog and it's getting on my nerves. I just know I'll soon be at the vet's putting her down and I'm easily rubbed right now....

[79XS11F]

Is there a possibility that the sprockets have some wear combined with chain stretch? Or perhaps if the chain is an after market item that it is not "exactly" the same as a OEM chain. When I set my bikes up there was only the slightest deviation of the cam dots from the cap marks. This was the case for both the engines which both have original cam chains. I have not checked that since sealing both engines up but I will check it the next time the valve covers are off.
Rob

[thewiz]

Hey, Rob ..

I'm sure the cam sprockets and chain have very minimal wear. There are no signs of wear in there at all, leading me to believe that the guy I bought the motor from was telling the truth. 7K miles on it.

Also, the dots came out mighty close when I stuck a punch down the #1 plug hole and felt with my thumb as the piston rose to the top. Problem is/was that you couldn't tell where the STATIC timing reference point was cuz no marks lined up when the motor was running. Turns out that the mechanical advance was seized up part way into the 'advance' positon. That's why it always cranked like a motor that was too far advanced ... duhhhh and everything looked outa' whack under the strobe light.

Once I replace the mechanical advance mechanism, I can start the motor up and adjust the pointer to match the 'F' on the wheel at idle and then tighten it down. Then the static mark (pointer) will be right position too. Replacing that advance unit should cure the performance problems ......... I think

[Bunk]

Finding TDC

I haven't read all of the threads, so I am not sure if this has been mentioned. I would not rely on the cam or cam chain timing marks to find true TDC. With the heads still on the bike you need to put a "positive stop tool" in the spark plug hole of # 1 cylinder. With this stop in place slowly rotate the crank (by hand) clockwise until it stops. At this point may a mark on the timing disk in line with the timing pointer. Now rotate the crank counter clockwise until it again stops. Then put a second mark on the timing disk in line with the timing pointer. True TDC will be the middle point between these two marks.

With the heads off of the engine you can use a dial indicator.

You can get this "positve stop" tool from companies like Jegs or Summit. You can also make your own with an old spark plug.