416 timing Q?

[L.Vegas400]

how can a person tell if he installed the cam gear on the right way or if its 180 deg out. if my understandings are correct the plug only fires every other revolution, so hoe is it you know the cam is not 180 out? or does the plug fire every time, but only when the cylinder is compressed does it create a bang?

[UglyMotha™]

line the marks up on your flywheel with the marks on the sidecase as defined in your manual i will usally stick a screwdriver down thru the hole for the spark plug to make sure the piston is tdc at this point you cam should have the lobes hangin down and line the marks on the timing gear level with the head

[44oEX]

what he said


but I know what you mean I had the same problem. You basicly have to try and start it if it doesn't start take the timing chain off the cam sproket and turn the motor one full turn ( timing mark on the flywheel ). and then try it again.

[L.Vegas400]

Originally posted by 44oEX
but I know what you mean I had the same problem. You basicly have to try and start it if it doesn't start take the timing chain off the cam sproket and turn the motor one full turn ( timing mark on the flywheel ). and then try it again.

this was what i was thinkin i would have to do. the thing is its been apart so long im not sure if it was at TDC of the compression stroke or the exhaust stroke.................

does anybody honestly know for 100% sure that a 4 stroke plug actually fires every other time, or everytime there is just nothing on the exhaust stroke to light with a spark. im thinkin they spark every time but just light stuff on the compression stroke.

[PHIL_B54]

im not 100% sure, but im thinking the 400ex fires every rev. i will do some looking around, but im thinkin that either way you put it in it will work. mine worked and im a mechanical retard.

[PHIL_B54]

yep found it, fires every rev, so you cant mess it up
http://www.exriders.com/vbb/showthread.php?s=&threadid=69377&perpage=15&highlight=spark%20every%20stroke&pagenumber=1

[L.Vegas400]

just after i posted i talked to a buddy of mine that has been workin on these since he was a kid and he also says yes, it fires every time the piston is ALMOST at TDC. so im golden:devil:

now all im waiting on is my oil cooler stuff from Jeggs, which will be here about thursday or so, then,,, ITS ON

[44oEX]

Sorry to disapoint you but I really don't think it fires every time cause I had to flip my cam around a few times before cause it would't start. and if it would spark in the exausts stroke and there would be a little gas left it would combuste ( burn ) in you exaust cause the valves would be open. ( that is not good. )

So if you bike doesn't start turn your cam around.

[PHIL_B54]

my guess is that it sparking and burning the un-burnt gas helps honda pass emmisions tests.

i dont know either way, i just searched and found an answer to help someone out

[L.Vegas400]

here are three different threads that say without a doubt that it fires every time the piston is up. also a person cant install a cam 180 out........



http://www.exriders.com/vbb/showthread.php?s=&threadid=69377&perpage=20&highlight=spark%20every%20time&pagenumber=2

http://www.exriders.com/vbb/showthread.php?s=&threadid=11389&highlight=spark+every+time

http://www.exriders.com/vbb/showthread.php?s=&threadid=15777&perpage=20&highlight=spark%20every%20time&pagenumber=2

[F-16Guy]

The ignition trigger is on the flywheel, right? There aren't any sensors on the valve train, so how would the ignition trigger know if the crank is on the compression stroke or the exhaust stroke? I would guess it sparks every stroke, but the exhaust gasses and lack of compression eliminate any chance of firing the escaping fumes.

[L.Vegas400]

Originally posted by F-16Guy
The ignition trigger is on the flywheel, right? There aren't any sensors on the valve train, so how would the ignition trigger know if the crank is on the compression stroke or the exhaust stroke? I would guess it sparks every stroke, but the exhaust gasses and lack of compression eliminate any chance of firing the escaping fumes.
you are correct. if youve had your left case cover off you can see the "mag pickup" as us helo crew chiefs call them. there is a small thingy on the outside of the flywheel that passes infront of that 'mag pickup' and thats when the plug sparks. every revolution it passes by and completes a circut(i guess).

when we ballance our rotorheads and such on our helos we have a magnetic pickup sensor that sends a signal to a computer to tell it each time a certin blade passes that point. it then computes it with vibrations and tell us exactly where, and how much weight to add. thats why i refer to it as a mag pickup..... just a bit of usless info

[F-16Guy]

What do you guys have at Nellis? PaveHawks? I can barely see them when I drive down past the base.

[L.Vegas400]

Originally posted by F-16Guy
What do you guys have at Nellis? PaveHawks? I can barely see them when I drive down past the base.
yeah. a while back the built on to the block fence. before that you could see them plain as day from the road. it kinda gave me a little pride being we are the only acft you can see from the road, but they decided for some reason or another to continue the fence all the way down to our hanger. there are 6 of them leaving between now and saturday for a TDY in texas. supposibly we wont be doing any flying while they are gone for the 2 weeks, which would be great, cause the ones that are left need some major TLC. they were flying the **** out of them just before the end of the fiscal year for some reason or another, then we ran out of $$ to order parts unless they were MICAP. all of us maintainers were a little sore at ops and such for that crap. well im getting all worked up about it so ill stop for now.

[F-16Guy]

Yep, same crap here. The end of the fiscal year is always a three ring circus. I think I'd rather have them flying (F-16s, anyway). When they get more than a day or two of down time, the crew chiefs like to dump a bunch of piddly little leaks on us, so we have to bust our buts to get them FMC.