pglaves
#13338
I use jumper wires from each plug thread section to known good chassis or engine grounds.
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Freshly Built R100 not running well!
- Thread starter s_alt
- Start date
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- Tags
- airhead carburator timing
I use jumper wires from each plug thread section to known good chassis or engine grounds.
stevenrankin
Active member
Hey Kurt and Paul
Thanks, I have learned something new today!
In regard to the clutch and fly wheel being out, The position of the flywheel on the Crank has no relevance to the actual timing of the engine, or cam shaft/crank shaft relationship. The engine will run just fine with the flywheel improperly installed. What does happen is the timing marks do not appear in the view port as they should. This makes it difficult to set timing or to adjust valves due to the OT mark not being in the window at top dead center.
So, forget the flywheel, The last thing done was a timing chain. IF the gears are not aligned, the timing marks will not appear in the view port because the timing is off, not because of an improperly installed flywheel. With the former, the bike will either not run at all or will run rough. With the later, the bike can run fine provided nothing was touched in the front of the engine such as the bean can position or the timing chain and gears.
Does this make sense or I am I missing something? St.
Thanks, I have learned something new today!
In regard to the clutch and fly wheel being out, The position of the flywheel on the Crank has no relevance to the actual timing of the engine, or cam shaft/crank shaft relationship. The engine will run just fine with the flywheel improperly installed. What does happen is the timing marks do not appear in the view port as they should. This makes it difficult to set timing or to adjust valves due to the OT mark not being in the window at top dead center.
So, forget the flywheel, The last thing done was a timing chain. IF the gears are not aligned, the timing marks will not appear in the view port because the timing is off, not because of an improperly installed flywheel. With the former, the bike will either not run at all or will run rough. With the later, the bike can run fine provided nothing was touched in the front of the engine such as the bean can position or the timing chain and gears.
Does this make sense or I am I missing something? St.
s_alt
New member
I did the clutch new install before I did the new timing chain and the timing chain at that point wasn't exposed yet. I followed my manual as well as some youtube videos and forums. I just made sure to install the flywheel exactly in the position it was when I removed it and used the proper tools to re-install the clutch without moving the crank system. It seems weird that I would install the flywheel improperly since there's only the 5 bolts that put it on so for it to be off by one bolt it would of been really noticeable since I was OT when I took it off.
s_alt
New member
No, this is totally on point.
I guess what Ill do next is remark the fly wheel using a stopper of sorts in the spark plugs holes and find where on the fly wheel my TDC is in the case that it was installed wrong. I read somewhere to do this and then divide the number of teeth between the two markings by 2. the older flywheels didn't have markings on them apparently so this was that procedure? but from there I can then see if those marks match up with the spark when doing the static timing procedure.
Unless there's another way to check TDC of the pistons without using the flywheel in the case if it is off?
pglaves
#13338
Get a #2 pencil or a plastic soda straw. Use this to insert into the spark plug hole and slowly rotate the engine. You will be able to feel the piston reach the end of its stroke and begin to retreat. Rock the crankshaft back and forth until you are happy that you are right at TDC.
stevenrankin
Active member
Any joy?
Hello S_alt, have you tried moving the bean can yet? You said it was fully retarded or have I missed something?
If, the cam and crank sprockets are aligned properly, the possible "set" position for the bean can would be just about the center of the slot. As I said, you might have to blip the throttle and play around with things a bit if you are trying to set it while running.
Kurt and Paul have given instructions on static timing.
If you have not been able to get the bike to idle, I can well imagine the cam/crank sprockets might be off a tooth. It might be possible you had the sprockets aligned and when you installed the chain, you moved one a tooth. If I recall, the marks on the sprockets are almost impossible to see or may not quite look like proper marks. Is it possible you mistook a mark on either the cam sprocket or the crank sprocket and aligned things with the wrong mark?
I am digging into my sieve like mind trying to remember a bike I worked on where a bearing covered the crankshaft sprocket mark. Anyone know what I am talking about?
Something else I have thought of, your bike might be cold blooded and not like running without the choke full on or half on until it warms up. I know my 84 R80RT is like that. When dead cold and started, it needs full choke. After it warms up a minute, I can go to half choke. If I try to turn off the choke completely before it is warmed up, it sputters and runs rough. So, what does that have to do with not being able to see the Z mark at full advance or seeing the OT mark at idle. Not much, the speed at full choke on will still be slow enough to see the OT mark. Just with the choke on, the bike might run long enough to get a look at the mark with a timing light and see if it is above or below the window.
If the bike ran fine before the repair, and now doesn't go back to the repair and check the work. All the other stuff going on distracts and makes it harder to work on. Am I just confusing things more here? St.
.
Hello S_alt, have you tried moving the bean can yet? You said it was fully retarded or have I missed something?
If, the cam and crank sprockets are aligned properly, the possible "set" position for the bean can would be just about the center of the slot. As I said, you might have to blip the throttle and play around with things a bit if you are trying to set it while running.
Kurt and Paul have given instructions on static timing.
If you have not been able to get the bike to idle, I can well imagine the cam/crank sprockets might be off a tooth. It might be possible you had the sprockets aligned and when you installed the chain, you moved one a tooth. If I recall, the marks on the sprockets are almost impossible to see or may not quite look like proper marks. Is it possible you mistook a mark on either the cam sprocket or the crank sprocket and aligned things with the wrong mark?
I am digging into my sieve like mind trying to remember a bike I worked on where a bearing covered the crankshaft sprocket mark. Anyone know what I am talking about?
Something else I have thought of, your bike might be cold blooded and not like running without the choke full on or half on until it warms up. I know my 84 R80RT is like that. When dead cold and started, it needs full choke. After it warms up a minute, I can go to half choke. If I try to turn off the choke completely before it is warmed up, it sputters and runs rough. So, what does that have to do with not being able to see the Z mark at full advance or seeing the OT mark at idle. Not much, the speed at full choke on will still be slow enough to see the OT mark. Just with the choke on, the bike might run long enough to get a look at the mark with a timing light and see if it is above or below the window.
If the bike ran fine before the repair, and now doesn't go back to the repair and check the work. All the other stuff going on distracts and makes it harder to work on. Am I just confusing things more here? St.
.
pglaves
#13338
He probably can't see the timing marks because the timing chain was installed with a sprocket at least one tooth off TDC. So once the ignition and valve timing is off all bets are off as to exactly how and when performance suffers. He can adjust the ignition timing. Valve timing can be slightly adjusted by altering the gap but to little or no advantage. If the chain is not correctly installed the thing will never run right.
stevenrankin
Active member
The I will eat crow in embarrassment
I have done the one thing I hate doing, I did not read the question properly. Thank you Nick for slapping me in the head so I can wake up and stop looking stupid. LOL.
I have to go with my number two comment and the comments made by Paul and Kurt. The last thing worked on, is the first thing to check. The Cam and crank are not aligned. Because the bike idles, it is most likely only one tooth in the wrong direction.
I apologize to S_alt and anyone who I misled or confused. St.
I have done the one thing I hate doing, I did not read the question properly. Thank you Nick for slapping me in the head so I can wake up and stop looking stupid. LOL.
I have to go with my number two comment and the comments made by Paul and Kurt. The last thing worked on, is the first thing to check. The Cam and crank are not aligned. Because the bike idles, it is most likely only one tooth in the wrong direction.
I apologize to S_alt and anyone who I misled or confused. St.
s_alt
New member
Alright guys. So its was a number of things. ha
woof. IM not even sure I mentioned this or if it had happened after the fact but my battery was draining when off so I had to find where that was coming from. The positive wire coming from the diode connected to the starter had moved and started to arch on some metal part.
ha
First of all timing was good. Checked the TDC with the straw in the plug hole method and everything lined up where it should be. Tried the static timing test but couldn't get it too work for some reason. Probably doing it wrong or maybe it doesn't work on post 1981 airheads with the canister?
Pulled the carbs and shot some carb cleaner through all the ports and holes.
I think I had flooded the bike before from trying it so much as to why it was stalling when pulling on the throttle or maybe because it was too retarded?
I got the idle at around 1k to start with and the idle screws in their stock position
I was able to advance the canister and quiet a bit! I felt so dumb since I was using a digital timing and had it set incorrectly that when I was shooting into the window it was just giving me a bunch of random sporadic readings it wasn't until I got it set correctly it gave me a consistent reading and there it was! the fire reading tucked below! I slowly advanced little by little at the same time adjusting my idle screws and making sure the carbs were still synched till I got the fire centered in the window at 1k idle. God damn that felt good figuring it out.
anyways, thank you all for your help.
I know someone on here persisted I advance the canister and i really appreciate that as well as all the other great tips and tricks.
It's running beautifully and rips! first gear seems a little sluggish unless I don't open the throttle more so maybe the idle jet is a little too small. Ive got a few different sizes I might play around with.
thank you again everyone
woof. IM not even sure I mentioned this or if it had happened after the fact but my battery was draining when off so I had to find where that was coming from. The positive wire coming from the diode connected to the starter had moved and started to arch on some metal part.
haFirst of all timing was good. Checked the TDC with the straw in the plug hole method and everything lined up where it should be. Tried the static timing test but couldn't get it too work for some reason. Probably doing it wrong or maybe it doesn't work on post 1981 airheads with the canister?
Pulled the carbs and shot some carb cleaner through all the ports and holes.
I think I had flooded the bike before from trying it so much as to why it was stalling when pulling on the throttle or maybe because it was too retarded?
I got the idle at around 1k to start with and the idle screws in their stock position
I was able to advance the canister and quiet a bit! I felt so dumb since I was using a digital timing and had it set incorrectly that when I was shooting into the window it was just giving me a bunch of random sporadic readings it wasn't until I got it set correctly it gave me a consistent reading and there it was! the fire reading tucked below! I slowly advanced little by little at the same time adjusting my idle screws and making sure the carbs were still synched till I got the fire centered in the window at 1k idle. God damn that felt good figuring it out.
anyways, thank you all for your help.
I know someone on here persisted I advance the canister and i really appreciate that as well as all the other great tips and tricks.
It's running beautifully and rips! first gear seems a little sluggish unless I don't open the throttle more so maybe the idle jet is a little too small. Ive got a few different sizes I might play around with.
thank you again everyone
stevenrankin
Active member
Good deal
Hey Good deal you got thing sorted.
Don't feel bad about the digital timing light caper, I have done the same thing in the past myself.
Just remember, the tune up mantra. Adjust valves first, Points (if you have them) timing, second, finally the carbs. If the first two things are out, fiddling with the carbs won't do much or will mask the problem.
For example, lately, my R80RT has started to idle badly and stall at lights. First thing I did when I got home was to let it cool down and check the valves. Yep, a tight exhaust valve on one side. Got it back into proper gap and bingo, the bike idles like it should. No carb adjustment need at all. Of course now, I am faced with the possibility of rebuilding heads the second time in 200K miles as the valve isn't staying in adjustment. Looks like the seat is recessing.
Back a long time ago, I messed with changing jets to see if I could "improve performance". All I ended up doing was stocking my tool box with various jets and emptying my wallet. The stock jets worked the best once I figured out how to do a proper tune up.
Hey, I am being a jerk, sorry, enjoy the ride, thank God, you got it back and thank God, we can ride. Cheers, St.
Hey Good deal you got thing sorted.
Don't feel bad about the digital timing light caper, I have done the same thing in the past myself.
Just remember, the tune up mantra. Adjust valves first, Points (if you have them) timing, second, finally the carbs. If the first two things are out, fiddling with the carbs won't do much or will mask the problem.
For example, lately, my R80RT has started to idle badly and stall at lights. First thing I did when I got home was to let it cool down and check the valves. Yep, a tight exhaust valve on one side. Got it back into proper gap and bingo, the bike idles like it should. No carb adjustment need at all. Of course now, I am faced with the possibility of rebuilding heads the second time in 200K miles as the valve isn't staying in adjustment. Looks like the seat is recessing.
Back a long time ago, I messed with changing jets to see if I could "improve performance". All I ended up doing was stocking my tool box with various jets and emptying my wallet. The stock jets worked the best once I figured out how to do a proper tune up.
Hey, I am being a jerk, sorry, enjoy the ride, thank God, you got it back and thank God, we can ride. Cheers, St.
