So I swapped cylinder heads on the F4i. Used service manual and forum write-ups to complete. We buttoned everything down and fired it up and it started surprisingly! But it sounds kinda funny. Kinda like a Air leaking/ticking. Checked all vacuum lines, and spark plugs torqed to spec, and exhaust headers are good and not leaking from there.

Noise is constant on startup to idle and increases or as you give it throttle.

Air is coming out of these tiny holes (4 total) between the Throttle bodies.



And I noticed that these black spacers are on 3 of the screws/plungers of throttle bodies but not one of them as seen in pic below. #1 is missing, #2,3,4 has them. Is this normal?



I know the timing is critical and needs to be perfect and it looks good to the naked eye. I included some pics below, not the best it's hard to see and the angles are hard to get clear pics.

Timing mark on crank lined up with mark on case.



Hard to see but EX mark lined up with head and if u zoom you can maybe see IN mark lined up as well.



Ex mark



IN mark



Cam bolts at even angle as illustrated in service manual.




I adjusted the valves too before we started it up. The new head had 2 shims under one bucket and missing a shim in another. So timed everything up and bolted down cam cover, then I measured the valve clearance. 3 were out of spec. Used the shims out of the old head to compensate.

Gonna re-check the valve clearance now, as I'm thinking my millimeters to inches math conversion possibly got messed up. Lol

Any input or advise as to why it sounds like this appreciated. I did take it for a test ride around the block a few times. Ran fine, no loss of power, idle is good, and throttle response is crisp. It just sounds weird. And I since the noise increases with throttle I was scared to take it on highway at high RPM's

 

did you hear the bike before you did all this work? if im not mistaken the F4i's have a bit of breathing noise, at least mine does.
and that is with the air baffles or whatever on the intake snorkels. the ticking is strange though, mine ticks until oil squirts on the lobes on cold starts, so it stops after 15 seconds or so. is it ticking constantly?
you put everything back in correctly right? the plastic guides, cam chain tensioner torque specifications, so on.
you can look at the throttle body on a parts website maybe it will show you what those things are
http://www.2wheelpros.com/oem-parts/...-assembly.html
i have no idea where that part is, but you actually been in there, i hope this helps

 

Yes the bike ran fine before without this noise. But a spark plug blew out Cylinder 1 and the threads stripped preventing me from screwing it back in. So I bought s new cylinder head off eBay. Guy said it was sitting in his garage on a shelf for a while (years I'm guessing)

Anyway I double checked the valve clearance and one of the intake valves was to tight. Could only fit a .004 feeler gauge in there when spec is .008. But it still sounds wierd, like a turbo. lol And the noise is constant from startup, and idle. And if you give it throttle it increases too. What's strange is it rides fine, I would think if it was a timing issue it would have a bog or lag to it. Not the case. In the write up I followed the guy synced the throttle bodies after cams were timed. I don't have vacuum gauges so I didn't sync anything. But I don't know if that's the problem.

Thanks for the link, it looks like those parts are #9 valve set starter. And #10 valve starter.

 

Yea the bike didn't sound like before I swapped heads. What happened was I blew the spark plug out of cylinder #1 and it stripped the threads preventing me from screwing it back in. Researched the Time-Sert idea and decided to just buy a new head off eBay. I'm guessing the guy had it laying on a shelf for a while (maybe years).

And yea everything went back on correctly. Didn't remove the old cam chain guides, just slipped the new head over them. It's a street fighter stunt bike so I don't run the plastic ram air intake tubes, & has Kleen air mod too.

Thanks for the link. It looks those screws in my pic with black spacers are #9 valve set starter, and #10 valve starter. Not sure what those do though. Lol gonna have to do some research.

The write up I followed showed the guy doing a Throttle body sync afterwards. I don't have any vacuum gauges so I didn't sync mine.

What's strange is the bike runs fine, it just sounds funny like a turbo. Lol I'm guessing if the timing was off it would bog and lag when giving it gas. I'm stumped and getting frustrated with this project. Lol

 

Exhaust leaks can sound like what youre describing...just a thought.

 

Yea that's what I read. I checked around where the exhaust headers connect to the head. And couldn't feel any air around coming out from around there, but maybe I'll unbolt and reattach to make sure. I got nothing to lose, and not much more to go on. Lol thanks.

 

Here's a vid if it helps

F4i strange sound - YouTube

 

sounds a lot like an exhaust leak to me

 

my vote is for exhaust leak too. if your cams were off, the bike would not run.