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TIMING MARKS I NEED TO UNDERSTAND

Posted: Mon Aug 17, 2020 3:14 pm
by TheFalcro
Well as a result of one thing leading to another on a "new to me" scooter, I am doing a number of things before this is put back into service next season. I've changed the oil and filter and am changing the coolant. I took the radiator off and have flushed everything flushable, while the radiator is off I decided to check the timing belts.... and here is what I have found. When I rotate the engine around so that the T-1 in the crankcase is lined up with the mark on the case the timing belts look like this...

Right side

Right side  appears to be off about a tooth
Right side appears to be off about a tooth

Left side

Left side appears to be off about a tooth
Left side appears to be off about a tooth

if I align the timing marks on the cam pulley's witht the marks on the case then the T-1 mark is no longer aligned with the mark on the top of the case and visa versa. This scooter runs as it is but at idle it seems to be rough, once above about 1800 to 2000 RPM it smooths out. What I am looking for advice on if it is possible that the scooter runs with the belts off a tooth and is there more than one position that the T-1 mark will make it appear as though the belts are off by a tooth. Additionally the right belt has more deflection (it is more loose) than the left, is this normal? Thank you to all the guru's that have helped me so far ALL the info I have gotten since joining has helped me in bringing this scooter back from the brink of a parts scooter.

Re: TIMING MARKS I NEED TO UNDERSTAND

Posted: Mon Aug 17, 2020 5:31 pm
by DenverWinger
The timing marks rarely line up "Exact", "Correct" is when moving the belt one cog would make the cam timing marks line up "worse".

I agree, the left cam looks like moving the belt one cog would make it line up better.

The odd thing is it's usually the right side that winds up installed off by a cog. But in this case I think moving that one by a cog would result in the marks lining up same or worse. Timing mark appears to be exactly half a cog either way.

Wouldn't hurt to re-tighten the belts (or replace them).

Re: TIMING MARKS I NEED TO UNDERSTAND

Posted: Mon Aug 17, 2020 5:46 pm
by TheFalcro
DenverWinger wrote:
Mon Aug 17, 2020 5:31 pm
The timing marks rarely line up "Exact", "Correct" is when moving the belt one cog would make the cam timing marks line up "worse".

I agree, the left cam looks like moving the belt one cog would make it line up better.

The odd thing is it's usually the right side that winds up installed off by a cog. But in this case I think moving that one by a cog would result in the marks lining up same or worse. Timing mark appears to be exactly half a cog either way.

Wouldn't hurt to re-tighten the belts (or replace them).
I am definitely replacing the belts but was unsure if the belts (pulley's ) alignment normally look like this when everything is "lined up" I am ordering new belts but leaving these on until I actually change them I want to get the cooling system flush finished and run the scooter to check carbs and such then I will put the new belts on last before I button up the mounts on the radiator since it will only be running enough to make sure the radiator fan is working and make certain that the oil level is correct. it won't even come off the stand while its warming up

Re: TIMING MARKS I NEED TO UNDERSTAND

Posted: Wed Aug 19, 2020 5:11 pm
by bruce swaybill
Since one timing mark is low and one is high, I think your T1 is not quite lined up with its mark. You gotta look square down hole! Take a second look...…..

Re: TIMING MARKS I NEED TO UNDERSTAND

Posted: Wed Aug 19, 2020 5:33 pm
by TheFalcro
bruce swaybill wrote:
Wed Aug 19, 2020 5:11 pm
Since one timing mark is low and one is high, I think your T1 is not quite lined up with its mark. You gotta look square down hole! Take a second look...…..
I have taken the second look early this morning when I removed the old belts. Using the T-1 port I lined it up perfectly. That's when I found out the belts were 1 tooth off. I locked the right cam gear on it's mark using the wrench/zip tie tool. Then loosened the tensioner and removed the belt. Then moving to the left I aligned it with it's mark on the case. Removed the tension and belt then checked the T-1 port, ...sure enough the T-1 on the crank was not quite lined up. It was off about 10° btdc (pre mark) it is now aligned perfectly. When the new belts arrive tomorrow I will install and report the outcome.

Re: TIMING MARKS I NEED TO UNDERSTAND

Posted: Wed Aug 19, 2020 5:54 pm
by DenverWinger
Easiest way to put the right belt on is to dispense with the wrench and zip tie and let the cam go where it wants to (about two cogs CCW). Then turn the crankshaft a corresponding two cogs CCW away from T1.

Then you can put the belt on without fighting the valve spring, easier that way. After the belt is on, turn the crank back to the T1 mark where it was, you'll see the cam mark lines up, too.

For the record, it doesn't hurt anything to manually turn cams and cranks around to set the marks without belts on.

Re: TIMING MARKS I NEED TO UNDERSTAND

Posted: Wed Aug 19, 2020 7:07 pm
by TheFalcro
DenverWinger wrote:
Wed Aug 19, 2020 5:54 pm
Easiest way to put the right belt on is to dispense with the wrench and zip tie and let the cam go where it wants to (about two cogs CCW). Then turn the crankshaft a corresponding two cogs CCW away from T1.

Then you can put the belt on without fighting the valve spring, easier that way. After the belt is on, turn the crank back to the T1 mark where it was, you'll see the cam mark lines up, too.

For the record, it doesn't hurt anything to manually turn cams and cranks around to set the marks without belts on.
Thank you! that is great news. I appreciate your knowledge. I am menacicaly inclinated but am totally new to the Goldwing. all help is good help at this point

Re: TIMING MARKS I NEED TO UNDERSTAND

Posted: Fri Aug 21, 2020 10:07 am
by indianakid
For the record, it can damage the valves to manually turn cams and cranks around to set the marks without belts on. If the crank is at TDC (for any cylinder) and the cams are "manually turned around" a valve will contact a piston. There is a procedure in the factory manual to set timing that must be followed to prevent damage.

Re: TIMING MARKS I NEED TO UNDERSTAND

Posted: Fri Aug 21, 2020 4:28 pm
by DenverWinger
If you are rotating by hand, any resistance will immediately be felt. Don't force it and won't be any damage.

Re: TIMING MARKS I NEED TO UNDERSTAND

Posted: Fri Aug 21, 2020 10:58 pm
by TheFalcro
Thank you everyone. The new belts are on and she is running significantly better. All of your help was invaluable. Valve adjust is next, they are pretty loose. You can clearly hear the tickety ticks. Oh boy I get to learn new things again lol. I promise I'll get pictures of her when she is dressed up again. She is just bashful right now, being naked and all...😂😂