my 749 is sick :(

[darkduc7]

so, i have what is a "common" idling problem on my '05 749. it likes to stall when you pull in the clutch and chop the throttle to stop at lights, ect. the bikes come very leaned out from the factory to pass emissions here in the usa. so the fix is normally to adjust the CO's at idle, and sync the throttle bodies, maybe a TPS reset. some bikes require the cams to be degreed/ valves adjusted.

i bring the bike to my dealer so they can hook up their fancy smancy computer, and they inform me that they cant get the correct mixture on my horizontal cylinder, and the hydrocarbons are sky high in just that cyl. they said this indicates worn valve guides or valves extremely out of adjustment. the quoted price to investigate was astronomical, so i picked the bike up and tore it apart at home.

so far ive found all valve clearances on the loose side, with one exhaust closer clearance grossly loose. hopefully i can adjust this and solve my problem, but this will all be a learning curve for me, ive never adjusted valves on a 4V ducati, just 2V. plus, i dont know how to check for worn valve guides...just wiggle the valve stem??

the bike only has just under 6k on it, and i know its due for a valve job. but im rather discouraged as this has been going on since like 2k miles...if the guides are bad, im not sure what i'll do, but i will be more than disgusted.

anyone have any experience working on these bikes and can give me some pointers? what do high hydrocarbons mean? exhaust buildup in the cyl? air leak? should they have done a leakdown check? tips for adjusting valves on a testastretta motor?


edit: sorry mods, just realized i should have maybe put this in bike maintenance, feel free to move if needed.

[SVRACER01]

Wirelessly posted (HTC EVO "DROID" : Mozilla/5.0 (Linux; U; Android 2.2; en-us; Sprint APA9292KT Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1)

Youre gonna have to pull the head to check the guide clearance.
Take the valves out and measure the OD if the valve stems and the ID of the guides.
If they need replacing you can do it with a hot plate at home.
You'll need a driver (a drift might work, but the proper tool for the job in this case would be best).
Get the head hot on the hot plate and just drive out the old and drive in the new. Should be pretty easy. With that said ive only done it on heads that this has been done to thousands of times.
If you plan on continuing to do this kind of work then you might as well get a valve spring compressor while you're at it. It's like a big C clamp with a bucket on the end so you can get the valve keys in and out with a magnet.
It's gonna take some time, but it will go A LOT faster the more you do it. Definitely doable though depending on how mechanically inclined you are.

[SVRACER01]

Wirelessly posted (HTC EVO "DROID" : Mozilla/5.0 (Linux; U; Android 2.2; en-us; Sprint APA9292KT Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1)

Oh, you'll need a micrometer and an ID tool.

If you're gonna have the valves in your hand checking runout wouldn't be bad idea either.

If this seems like too much for you to handle then just pull the heads and bring them to a shop or a machine shop and have them do the hard stuff.

Good luck, let us know how it goes

[Kurlon]

Good news, you have a Ducati, no need for a valve spring compressor. : )

[SVRACER01]

Wirelessly posted (HTC EVO "DROID" : Mozilla/5.0 (Linux; U; Android 2.2; en-us; Sprint APA9292KT Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1)

I wasn't sure, never seen the inside of Duc motor

[darkduc7]

Good news, you have a Ducati, no need for a valve spring compressor. : )

yup!

svracer01, thanks for the advice.

yeah, ive got all the right tools for the most part, but this will be my first head removal endeavor on a duc if i choose to do so. i also work as an aircraft mechanic, so i have access to some experience machinist guys.

is it reasonable for me to think i might just grab onto the valve stem with the rocker pressure relieved from them and wiggle the valve to check for looseness? i really am undecided as to just try adjusting the valves and hope they are the culprit or removing the whole head. im going off my dealers hunch right now on the guides, thats all. nothing else definitively points to valve guides...is it really worth removing the head to check them, or should i just adjust the valves and try it out? the valves alone are kind difficult....

[Kurlon]

Adjust the valves first. AFAIK the closer on the exhaust should be set to almost 0 clearance. If it's loose at low throttle/low RPM it'll run like shit and no amount of tweaking the mix will cure it.

[darkduc7]

Adjust the valves first. AFAIK the closer on the exhaust should be set to almost 0 clearance. If it's loose at low throttle/low RPM it'll run like shit and no amount of tweaking the mix will cure it.

i hope you are right! it makes sense. the only reason ive mentioned the guides is because my dealer was convinced they were the issue. other than that, im not sure i wanna dig that deep without exploring less invasive adjustments.

[BLACK SQUIRREL]

or you could just NOT chop the throttle at stop lights

Problem fixed

[darkduc7]

or you could just NOT chop the throttle at stop lights

Problem fixed

Yeah, been doing that all summer. Sick of that solution.

[Ryno]

pretty crazy to have valve guides be gone at six thousand miles. Does it smoke at all when you first start it?

[darkduc7]

pretty crazy to have valve guides be gone at six thousand miles. Does it smoke at all when you first start it?

no smoke, in fact it runs fine all the time except for stopping at a light. the revs fall and....it dies.

im not convinced theres anything wrong with the guides...

[darkduc7]

heres what i found when i checked my valve clearances:

horizontal cyl (supposedly the problematic one):

intake side, openers .006 on both
closers .008 on both
exhaust side, openers <.002 and .002
closers .012 and .013


vertical cyl

intake side, openers .006 and .005
closers .008 and .009
exhaust side, openers .004 and .005
closers .010 and .013

ive heard that .002 to .005 is optimum for all, but im going to do more research. even if some of them are within the wide factory spec, i'd like to get all of them to best-case, so then i can at least eliminate this as the cause to my idling issue. hopefully it just plain fixes it.

[PinHead]

Look here.
Might help you out some?

[darkduc7]

thanks, but my motor is a testastretta so different clearances apply

[Kurlon]

Wow, LOOSE closers. I'd say you've found your culprit.

Edit: Only problem valve guides in Ducs I can recall off the top of my head were some of the 2v motors recently, Multis were involved so either the 620 or 1000DS if I recall correctly, not all years.

[darkduc7]

Wow, LOOSE closers. I'd say you've found your culprit.

yeah! i hope this fixes it. cant make it worse lol.

[darkduc7]

kurlon, i was able to get a little wiggle on the valve stems without rocker pressure on them. is that normal?

i would have been alarmed if it was just one or two, but they all seemed to have a little play

[Kurlon]

I haven't had my hands on installed Duc valves personally, all the motors I have there wasn't much play side to side that I recall. I'm hoping to be assembling a head this weekend so I'll report what I find with it. I need to ream the guides a touch loose so I'll be working with a friend I trust and find out what he thinks.

[scottieducati]

I can't say I've heard of valve guides going that quickly but I have zero experience with that motor. My best guess is your clearances are the biggest issue, as weird as it sounds... how's your rectifier / regulator? Very common issue on some Ducati's that might just not be sending enough juices when the RPM's drop suddenly.

[darkduc7]

I can't say I've heard of valve guides going that quickly but I have zero experience with that motor. My best guess is your clearances are the biggest issue, as weird as it sounds... how's your rectifier / regulator? Very common issue on some Ducati's that might just not be sending enough juices when the RPM's drop suddenly.

yeah, ive had those regulator issues on older 2v's. this one checks good. thanks for the heads up though!

[darkduc7]

gettng closer on getting the valves adjusted...but ive lost two tiny magnetic half rings in the horizontal cyl head. FUUUUUUUCK.

i had previously blocked off oil holes and all, so they cant go far...but ive searched for a combined 5 hours now and no luck. i hope i can get this finished before the 29th....

[darkduc7]

andd...its alive! rolled it out and started it just a few minutes ago. so happy it didnt blow up...i had it alllll torn apart, but apparently i did ok. it seemed to idle very solid, better than before. but that could be my imagination, and i need to test it at speed.

cant wait to shake it down tomorrow, and maybe bring it to bomo on wenesday. weather is looking sweet!

[DuncanMoto]

Wow, LOOSE closers. I'd say you've found your culprit.

Edit: Only problem valve guides in Ducs I can recall off the top of my head were some of the 2v motors recently, Multis were involved so either the 620 or 1000DS if I recall correctly, not all years.

Correct!
I happen to have the 2003 ss1000ds with worn guides. It is a known issue for those engines.

[Tricklidz]

gettng closer on getting the valves adjusted...but ive lost two tiny magnetic half rings in the horizontal cyl head. FUUUUUUUCK.

i had previously blocked off oil holes and all, so they cant go far...but ive searched for a combined 5 hours now and no luck. i hope i can get this finished before the 29th....

I assume you found the half rings? They can hint deep in there.....I know from experience.

Please explain "magnetic"??- half rings!!