Ironhead 1977 Ironhead cam timing gears

Freewheeler · #1 14th March 2009

Hi there

I hope you are well,

I hope someone can help me please. Im building a hardtail chopper using a 1977 Ironhead engine and have a problem.

I removed the gearcase cover and when trying to refit it noticed the rear intake cam gear wouldnt line up with its slot in the cover neither does it engage with the adjacent cam gears. It will push down a bit but its definitely under tension, maybe the engine is on its exhaust/intake stroke..?

Between removing the cover and noticing this I had spun the starter motor a few times (there is no ignition circuit so the bike didnt fire).

To my mind what I have now is a bike whose timing is out as the pinion gear is no longer lined up with the cam gears. I am unable to see any kind of mark on the pinion gear - I can see the lockwasher and thought a mark may be underneath however I cant undo the locknut as, without the adjacent cam gears being engaged, I cant get any purchase on it with a socket.

So my question is - is there any way to get my timing lined up without having to strip the motor down please? Also what are the chances I have damaged something as I believe the rear intake cam gear doesnt line up with the cover as the engine wasnt at BDC when I removed the cover.

Any help would be much appreciated.

Nick

FourCams · #2 14th March 2009

You need to loosen the pushrod adjusters and take out the pushrods so there's no pressure from the valve springs on the lifters when you remove and replace the assembly.
If you can't see the mark on the pinion you can line up the front cylinder advance mark in the center of the timing window when you align the cam gears.
The service manual describes the procedure fairly well. The Clymer manual has a good description as well, and there's a sticky here in the Ironhead section that describes it as also. http://xlforum.net/vbportal/forums/s...d.php?t=239641
Take a close look at the gear teeth on the cams and make sure they weren't damaged when you spun the engine.
... and make sure the oil pump breather is timed too.

IronMick · #3 14th March 2009

Welcome! to the forum, Nick. Yes, the pushrods should have been removed before removing the gearcase cover. Please remember this for next time. I had a very difficult time in the beginning seeing the mark on the pinion. It can be very small. If it is hidden behind part of the lockwasher then it it time to curse the previous owner!

There are 3 timing marks on the #2 [rear intake] cam. When all the marks are lined up the middle one will line up with the pinion mark when the latter is at it's 11:00 o'clock position - every second rotation. If you rotate the thing until that middle mark is at that position, then look for the pinion mark, you might be able to see it?

Of course, this will be no good if the gears have been out then in again.

Freewheeler · #4 15th March 2009

Good Afternoon

Thanks for the welcome

You'll never guess...a previous owner had refitted the pinion gear the wrong way round with the bevel facing out rather than in.

Also thanks for the advice about the pushrods, ill back them off right now!

Nick

FourCams · #5 15th March 2009

I'm glad to hear that you found it

Here's some info that might come in handy when you get it back together:
http://xlforum.net/vbportal/forums/s...ad.php?t=44143

Freewheeler · #6 16th March 2009

Thanks very much

Im impressed with the amount of information on here and spent a good couple of hours last night reading through on how to connect my oil tank and correct routing for the crankcase breathers.

I also added a new work to my vocabulary - foo-foo

Will keep in touch and thanks again,

Nick