Gentlemen, I have a question.
Like a good, conscientious old-bike-owner, I'm changing my current timing belts because they could be quite ripe. So, following my manual's instructions I lined up the T 1 timing mark just so and yes, the cam shaft pulley's UP mark was up, and lo and behold the timing marks on both camshaft pulleys are at least two teeth off !!??? How can this be?... because the engine ran fine.
So my question is do I violate the principal of "don't fix it if it ain't broke, and install the new belts just as I found the old ones, or do I adhere strictly to the letter of the law and realign my timing marks?
Hmmmm.....I'm a bit stressed about this and could use some advice from more experienced mechanics.
The bike is a 1984 Aspencade with 120,000 miles
p.s. One more thing----the new belts----it doesn't matter which direction of rotation you choose, right? Cuz I can't seem to find any direction marks on 'em.
i just aligned the camgears up on the case marks once it was up on T1 and then changed the belts,didn't worry if it wasn't exactly up on T1,really didn't cross my mind actually
just made sure that when both belts were back on that both toiming marks came up same on each side when i was done
was i right ? ran fine before,runs fine now
timing belts aren't directional,just make sure you turn engine over my hand when checking belt alignment and setting belt adjusters
dont sweat the right side cam gear turning clockwise when you take the right belt off,i just brought it back to the mark,and reinstalled belt and rechecked alignment both sides,tightened adjusters as described in manual, reinstalled pg's and buttoned it back up done
simple,fast and not a problem
Hello All! I found the same ! The old belt may have streched a bit. I put ever thing back new and did it by the fsm as far as belt tension. The idea to let the tensioner springs adjust the belt didnt set well with me. The po had belts so loose I wonder how they stayed on. I turned the engine to a place the valve spring was not working on the belt(after all was lined up) and adjusted the slack per fsm. I thought I had a problem when I rode it. The engine did not go below 1600 rpm. The engine had been adjusted around the retarded timing the belts created. It runs great now that its been readjusted.I'm not trying to tell you what to do just what I found. Thanks !
What timing marks are you looking at to think the belts are off by two teeth? If the "up " marks are straight up AND the T-1 mark is centered in the sight hole, the timing is correct. Are you looking at the T-1 mark, or the F-1 mark?
Thanks guys for the responses. I'm in a very rural neighborhood and my local 24 year old Honda service man would blink and go "whaa....?" at any question regarding a motorcycle dating from the 20th century back.
Neoracer....you seem to be saying that I should ignore the current timing belt conditions on my bike and just reset everything according to the manual. Seems reasonable. But I'm curious.....so, how flexible is this camshaft timing situation? How many teeth can a belt be off and still run the engine satisfactorily? Am I fretting over nothing?
Here's the scary thing I'm seeing: So, I line up the T1 mark with my housing mark, per manual, and look at my camshaft pulleys and they're off a couple of teeth. So I go from the other direction and l line up the camshaft pulley marks with the housing marks, I look at my crankshaft timing viewing hole and the crankshaft has turned to the point that I CAN SEE NO MARKS AT ALL! It's that much off. Freaky, eh? And yet, the engine ran fine. Argh. I REALLY don't want to screw this up and put every effing thing back together and find it don't run so well, or not at all anymore.
Piratekyng,
I would make sure All three things(both cam pulleys, and the engine crank) are at TDC when you put the new belts on. The timing mark inside the inspection hole over the top of the engine must read T-1 at TDC(center of the inspection hole), at the same time both the right and left side cams are at the 12 o'clock position or UP position when the belts go on. This requires placing pressure counter clockwise on the right side cam with a wrench or have help holding it there while you slide the belt on it. Pressure from the valves causes the right side cam(thats right as your seated on the bike) to naturally rotate "clockwise" (as your looking at it from the front of bike.) When looking at the cam pulleys, you will see the UP marks at 12:00 o'clock, and the right pulley will show the dots or mark aligned at the 9:00 o'clock position mark on the outer casing, and 3:00 o'clock and at 12:00 o'clock positions on the left. It gets confusing, but keep in mind left and right are always as your seated on the bike. Reference to clock positions are determined as your looking at the front of the engine. The Honda shop Manual has a nice picture of this process showing the cams and crank in position and the location of the alignment marks.
Keep checking repeatedly all the alignments when doing this. It easy to let the right cam turn or slip because of the valve pressure. Keep checking the inspection hole to make sure the crank hasn't turned on you. The new belts can rotate either way. I put mine on so I can read the numbers when I take off the covers. Don't rotate the engine crank or the cams any significant degree or independently of each other after you take the old belts off. Since you have already opened the inspection hole, and seen T-1, you should be ok. Just don't rotate that crank more that it takes to keep T-1 in sight and lined up. Turning the crank without the cams turning is how valves get bent.
Good luck,
Just so we're on the same page as far what is the left and right side on the engine....
Manual Quote:
"In the following steps, "lefthand" and "righthand" refer to the engine as it sits in the bike's frame. "Clockwise" and "counterclockwise" are as veiwed from the fron of the bike.
The reason I bring this up is because, the best I remember, the left side cam is the one that has a tendancy to be out of time by about 1-2 teeth due to valve pressure on the camshaft when installing the timing belts...
roscoepc Wrote:Just so we're on the same page as far what is the left and right side on the engine....
Manual Quote:
"In the following steps, "lefthand" and "righthand" refer to the engine as it sits in the bike's frame. "Clockwise" and "counterclockwise" are as veiwed from the fron of the bike.
The reason I bring this up is because, the best I remember, the left side cam is the one that has a tendancy to be out of time by about 1-2 teeth due to valve pressure on the camshaft when installing the timing belts...
Evening Roscoepc,
For me it was the right cam that kept rotating clockwise, and had to be pulled back to the UP and 9:00 o'clock position when sliding on the belt. The left cam seemed to stay in place for me better..
Piratekyng Wrote:How many teeth can a belt be off and still run the engine satisfactorily? Am I fretting over nothing?
For best efficiency the timing belts need to be installed right on the marks on both cam and crank. If they are off by a couple teeth it is likely that you could bend a valve at high rpm if a valve touches a piston. At the least, your engine will suffer poor performance if the marks are off.
Thanks for the helpful advice from one and all. I spent a bit more time and consultation (thanks Don) on it yesterday. I found on close inspection I had mistaken the exact amount it was off. Now it looks like it's only one tooth. I've attached pictures of the two cams and the timing mark on the crankcase. By all accounts the engine can run (and did!) under this condition, but perhaps not as well as it could.
So my plan is to move the belts one notch and get the thing set up to factory specs. I hope to see a bit of an improvement in performance, but I'll certainly just settle for peace of mind.
Oil leaks are a bad thing. The head cover gaskets on this thing were rock hard and someone had coated the surfaces with silicone instead of replacing the gaskets. There is oil all over this effing engine, top to bottom when you get past the wipable surfaces. I think the radiator fan got ahold of it and blew it all around the top of the engine as well as the bottom. Oil had soaked the timing cover gaskets and softened them up to the point that oil was seaping into the timing belt cases----never a good thing. I'm using simple green and a small paint brush and cleaning everything off as I go.
I'm going to take the pipes off next, change the gear shifter seal and clean up the bottom of the engine. I really wish I had a work table so I could get this bike and myself off the floor. This is becoming a long term project, but that's okay---I have two other bikes to ride to work and we have no time to do any distance rides this summer anyway. I want to get this done right and do it all at once while I've got it apart.
The last picture is my bike in progress with some paunchy old balding guy.
[attachment=1][attachment=2][attachment=3][attachment=0]
Weird that the bottom picture came out as a mirror image. Just noticed that. I took it with my built in laptop camera. hmmmm.
My bike is an Adnoh Gniwdlog
I read this somewhere...
I set my crank to the T-1 mark and made a small mark on the front of the crankshaft and on the housing just behind it. I believe I used the back belt guide on the crank...it's close to the housing.
This was not to substitute using the T-1 mark but only as a quick reference as I was lining things up. Then I verified the T-1 mark and the camshaft marks after snugging the idlers.
Like I said, I can't take credit, just passed it on from something I ran across somewhere.
...but then again, I couldn't understand why a fan wouldn't run without wires connected. :oops: So take this bit of info with a grain...no...truck of salt. :lol:
Thanks for the suggestion Gary. I'll use that in absence of any apparent mark on my crankshaft pulley.
Any one else besides me here notice how handy in general a sharpie or "Marks Alot" permanent marker can be when working on bikes?
As far as your whole fan issue goes, Gary, maybe you should heed the advice Indiana Jone's father gave to him in installment three, when he was unable to get that grail out of his mind: "let it go, Junior, let it go".
:d
Quote: I really wish I had a work table so I could get this bike and myself off the floor
I've seen some nice bike lifts at Harbor Freight and Sears. Pretty reasonable if you find them on sale. One of these days I'm bringing one home....that would be just awesome for oil changes, cleaning, etc.
Too old to crawl around on the floor!!!! [-X
85GL1200I Wrote:Too old to crawl around on the floor!!!! [-X
I'm right there with you man.
Something very close to this would be pretty cool.
<!-- m --><a class="postlink" href="http://www.webbikeworld.com/motorcycle-table-lift">http://www.webbikeworld.com/motorcycle-table-lift</a><!-- m -->
All it takes is money----dammit!