Timing off on rear cylinder?
12-06-2015, 05:30 AM
#1
Junior Member
Squid
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Join Date: Dec 2015
Posts: 5
Timing off on rear cylinder?
Why does it look like my timings off so bad on the rear cylinder? Pictures taken at top dead center. Looks like intake is a little more off than exhaust. Front cylinders fine. Same number of links between RI and RE on rear as FI and FE on front. If I rotate the engine so RI mark is level with the cylinder head RT isn't even visible through the alternator cover. 25K on the bike and photos are taken with CCT installed. Bike seems to run fine... although I bought it this way so I wouldn't know any difference. Could the timing chain really be stretched that bad? Any ideas? Thanks.
12-06-2015, 06:18 AM
#2
That one guy
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Join Date: Jun 2015
Location: Broken Arrow
Posts: 228
I'm not a timing expert by any means but could you explain what kind of cct's are on the bike? Stock automatics or replacement manuals. The cct's seem to be the kiss of death for these bikes because the springs in the automatic cct's goes bad causing a slip at rapid rpm changes.
12-06-2015, 10:34 AM
#5
Well take off, eh.
SuperBike
Join Date: Jun 2012
Location: QC, Canada
Posts: 1,201
Timing chain isn't stretched. Timing gear probably rotated upon CCT replacement, and jumped a tooth. Here's a good read on the subject, and will help you fix it.
https://www.superhawkforum.com/forum...pe-ccts-11275/
If you're the one who did the replacement, try and remember if you heard the chain jump on the gear.
https://www.superhawkforum.com/forum...pe-ccts-11275/
If you're the one who did the replacement, try and remember if you heard the chain jump on the gear.
12-06-2015, 11:56 AM
#7
VTR virgin
Superstock
Join Date: Mar 2015
Location: Auckland, New Zealand
Posts: 446
From the look of the photo, I'd say the cam timing is off by one tooth on the rear intake cam. When I installed manual CCTs in my 70000km old bike, I couldn't get the timing exactly right between the crank and sprocket but that was due to a little chain stretch and even with that the timing was less than half a tooth off.
The timing marks for both intake and exhaust sprocket should line up exactly parallel with the gasket surface if they are timed correctly to each other.
The timing marks for both intake and exhaust sprocket should line up exactly parallel with the gasket surface if they are timed correctly to each other.
12-07-2015, 05:30 PM
#8
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Squid
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The timing definitely didn't jump... at least when I was working on it. I had the valve covers off and was watching very carefully the whole time. In fact, that picture was before I even removed the stock cct. And since there's the same number of links between RI and RE on rear as FI and FE on front and the front marks line up pretty well with the cylinder head I don't think it could have jumped a tooth. That just makes me think the chains stretched a lot some how. I remember reading somewhere on this forum someone stated the correct amount of links between the RI and RE or FI and FE and I know that's how many I counted (but I forget the actual number). Anybody every replaced one? Are they a pain? What happens if I just rotate the intake cam one tooth so the marks are lined up instead of replacing the chain lol?
I think this picture showing the lobes of the rear was taken at the same time as the one showing the side of the cam (although I could be mistaken). I did this a couple months ago but since it's getting cold out now I figure I'll have some time to sort this out if it's a problem. Thanks for the help.
I think this picture showing the lobes of the rear was taken at the same time as the one showing the side of the cam (although I could be mistaken). I did this a couple months ago but since it's getting cold out now I figure I'll have some time to sort this out if it's a problem. Thanks for the help.
12-07-2015, 05:35 PM
#9
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Squid
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If I wasn't clear in my previous post... I should have said that picture showing the lobes was probably taking with the rear piston at the same position (TDC) as the picture showing the timing marks.
12-07-2015, 07:54 PM
#10
VTR virgin
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Location: Auckland, New Zealand
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Well SP it's not so easy to diagnose at a distance but here's what I know.
When the RT mark on the flywheel is in the right spot, then the rear head sprockets and cams should be as shown:
Here's the alignment (front head) that I actually had with my stretched camchain (with flywheel in the correct position):
You will always have the right number of links between the sprockets, but the sprockets might be rotated relative to each other, or relative to the crank.
First thing I would check is that the timing marks on the sprockets are exactly right relative to each other, i.e. you can rotate them around until the marks for both intake and exhaust are parallel to the head. If you can't do that, then one is offset to the other and out of timing.
Next up is to check that the timing is correct to the crank, bearing in mind some chain stretch will have occurred depending on mileage so the alignment won't be exact.
Of course you've stated that the bike was running fine with the timing as it was (and it is pretty hard to screw this up fitting MCCTs unless the cams were pushing on valves at the time of removal) so maybe just leave it as is?
When the RT mark on the flywheel is in the right spot, then the rear head sprockets and cams should be as shown:
Here's the alignment (front head) that I actually had with my stretched camchain (with flywheel in the correct position):
You will always have the right number of links between the sprockets, but the sprockets might be rotated relative to each other, or relative to the crank.
First thing I would check is that the timing marks on the sprockets are exactly right relative to each other, i.e. you can rotate them around until the marks for both intake and exhaust are parallel to the head. If you can't do that, then one is offset to the other and out of timing.
Next up is to check that the timing is correct to the crank, bearing in mind some chain stretch will have occurred depending on mileage so the alignment won't be exact.
Of course you've stated that the bike was running fine with the timing as it was (and it is pretty hard to screw this up fitting MCCTs unless the cams were pushing on valves at the time of removal) so maybe just leave it as is?
12-08-2015, 02:12 PM
#11
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Squid
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Join Date: Dec 2015
Posts: 5
I guess I could leave them the way the are. I'm going to adjust my valves this winter so I can try rotating the intake cam one tooth.
What I got from wyldryce back in 07
https://www.superhawkforum.com/forum...ff-mark-11614/
"I just posted this in the KB yesterday, but if you have the valve covers off again, I would count the chain links/pins between the timing marks on the intake and exhaust cam. If correct it should be 18 links or 36 pins. If you have that, then you will be in phase and only have to concentrate on getting the timing marks as close to "correct" as you can. Mine done line up 100% either at 34k miles. Mine was doing what you described, and though I thought I was properly adjusted, a simple pin count proved I was a tooth off on my rear cylinder exhaust cam. Not sure why the book doesn't mention counting links/pins. Oh well.
Hope this helps,"
https://www.superhawkforum.com/forum...ff-mark-11614/
"I just posted this in the KB yesterday, but if you have the valve covers off again, I would count the chain links/pins between the timing marks on the intake and exhaust cam. If correct it should be 18 links or 36 pins. If you have that, then you will be in phase and only have to concentrate on getting the timing marks as close to "correct" as you can. Mine done line up 100% either at 34k miles. Mine was doing what you described, and though I thought I was properly adjusted, a simple pin count proved I was a tooth off on my rear cylinder exhaust cam. Not sure why the book doesn't mention counting links/pins. Oh well.
Hope this helps,"
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