Ironhead 72 ih stroker advise needed

[rocketnorton]

finally got to ride it y'day
tryin to be winter round here
i'll just say it seems pretty healthy
hi gearing is nice on hwy
thanks to all for the advise/thoughts
pretty happy w/it

[sportsterpaul]

Congratulations, now get them miles of smiles, happy for you!

[rocketnorton]

been ridin it some
goes pretty good
broke the cv choke cable, so put the s&s b on
was startin good, then...
checkin valves, timin, etc
front valves were both lil tight, so loosened them
timing looks good, or at least very close

flywheel is stamped 3894-11 visible thru timin hole, lookin on nets hasnt found anything
tryed s&s & t&o sites
any ideas?

also, mentioned earlier in this thread was a bc logo in jug bases
today found same logo on backside of rear drum

[needspeed]

From a S+S catalog I have and this site, the -11 suffix is a 4-1/2 stroke.

http://www.nightrider.com/biketech/d...s/flywheel.pdf

[rocketnorton]

thx
there is only one timing mark on [mine] it, not 3 as described there
it is just a line, as seen in fsm, tho rim face is narrower

[Chuckthebeatertruck]

Originally Posted by rocketnorton

thx
there is only one timing mark on [mine] it, not 3 as described there
it is just a line, as seen in fsm, tho rim face is narrower

The instruction sheet shared is the late 90s version.

Earlier S&S wheels came in different varieties.

Most of the forged steels you'll run into in bikes that have been together 40 or so years are two vertical lines. One for front 45 degrees and one for rear 45 degrees.

A 4.5" bike is a nice lively thing and will give you a solid 71-72" bike. You'll like riding it a lot and don't have to fear spinning it in upper RPM ranges where it should get very, very lively.

Enjoy!

[Ferrous Head]

was startin good, then...

Some problem now ?

[rocketnorton]

ya, dunno if its me, the bike, or the s&s - b, no pump, 29 & 70 jets - replacing cv
both front valves were lil tight, but would still turn
points were opened up
has been corrected
gonna hafta look again at timing marks, re chuck's post
maybe timed to wrong mark?
almost no retard left @ points plate

and ya, it likes to go good after 4k

[Ferrous Head]

OK.

If the bike was starting and running fine and you only changed the carb because you broke the choke cable and, now, it's hard to start or not running too well the most likely culprit is the S&S.

If you have any doubts about what you are using as a timing point use the physical properties of the engine.
On the front cylinder make sure the piston is coming up on the compression stroke. This will be occurring as the intake valve closes.
What I do is to pull the push rod keeper and hold the push rod covers up.
Holding onto the tappet rotate the engine. (Get someone to help you, it's easier)
You will feel the intake tappet rise and fall. As it's falling your coming up on compression.
Buy, beg or steal piston position indicator. These are handy little tools. You can substitute a pencil or straw or something similar but a proper PPI just makes life so easy.
When the piston is 11/16's " (check with the FSM - I'm old) before TDC whatever mark that is in the window is your timing mark. I don't care if it's one line, two lines, one dot, two dots, an infinity sign or even blank.
This bit can be "fiddly" but you can do it. The engine needs to be turning forward as you reach the correct point. There is some play in the system and if your turning the engine backwards to reach the 11/16th's position you'll be out a Micky hair.

The laws of physics are what they are.
Just bear in mind this is the advanced timing mark. Where the engine will fire when running at over 2,000 rpm. If you have any kind of advance it must be set to fully advanced to check the timing at this point.

[needspeed]

Originally Posted by Ferrous Head

When the piston is 11/16's " before TDC whatever mark that is in the window is your timing mark. I don't care if it's one line, two lines, one dot, two dots, an infinity sign or even blank.

This is true with a stock stroke.
At 45° BTC the piston will be 11/16 down in the bore with a stock stroke.



But in my opinion the easiest way to find the timing mark is to put the REAR cylinder at TDC. You can get close enough by just looking through the spark plug hole.

Any mark that is then in the timing hole is the front cylinder advance mark.

A mark centered is 45°
A mark just showing in the rear of the hole is at 40.