Ducati Monster Forum

Moto Board => Tech => Topic started by: jerryz on March 12, 2010, 02:04:51 AM

Title: Valve shimming problems ...arrrghhh!
Post by: jerryz on March 12, 2010, 02:04:51 AM
doing the S4 valve service today ..one anomaly that bothers me the openers have drifted over the last 6500 miles by 0.001mm thats acceptable but the closers seem to have drifted by 0.003mm that seems a lot ? The rockers are all fine so should i just carry on re -shimming or should i pull the heads and investigate?

Was putting one of the closers back when a collet jammed now the damn thing wont move any ideas or will i have to remove head to support the valve to remove the stuck collet.

Usually valve jobs are easy for me but this one is being an arse ...did a 996 last week and it was easy peasy .


jerry
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Title: Re: Valve shimming problems ...arrrghhh!
Post by: Keld on March 12, 2010, 06:35:48 AM
Hi
if your numbers is right, I wonder what you use for measurement, under 0.01mm is hard/expensive to do.
Title: Re: Valve shimming problems ...arrrghhh!
Post by: gage on March 12, 2010, 07:56:20 AM
Quote from: Keld on March 12, 2010, 06:35:48 AM
Hi
if your numbers is right, I wonder what you use for measurement, under 0.01mm is hard/expensive to do.

+1 near impossible... Are those inch measurements?
Title: Re: Valve shimming problems ...arrrghhh!
Post by: Speeddog on March 12, 2010, 07:57:53 AM
I think you've gotten the decimal point off a bit on those measurements.

As far as the jammed collet goes....

Get the closer rocker held back as far as you can.
Push the valve down until it contacts the piston.
*Gently* tap on the closer, it should come loose.
Title: Re: Valve shimming problems ...arrrghhh!
Post by: gage on March 12, 2010, 11:13:11 AM
Quote from: Speeddog on March 12, 2010, 07:57:53 AM
I think you've gotten the decimal point off a bit on those measurements.

As far as the jammed collet goes....

Get the closer rocker held back as far as you can.
Push the valve down until it contacts the piston.
*Gently* tap on the closer, it should come loose.

I'd add that it will be helpful to have a magnet positioned somewhere in the vicinity to capure the collet should things break loose.
Title: Re: Valve shimming problems ...arrrghhh!
Post by: jerryz on March 12, 2010, 05:12:25 PM
sorry decimal point out here when posting the openers are only a thou of a mm out of spec  but the closers have 3thou  mm out thats a lot in my mind .
I have Mitutoyo digital vernier and micrometer
Title: Re: Valve shimming problems ...arrrghhh!
Post by: ducpainter on March 12, 2010, 05:15:52 PM
Quote from: jerryz on March 12, 2010, 05:12:25 PM
sorry decimal point out here when posting the openers are only a thou of a mm out of spec  but the closers have 3thou  mm out thats a lot in my mind .
I have Mitutoyo digital vernier and micrometer
.003 millimeters = 0.000118110236 inches

That's a lot?
Title: Re: Valve shimming problems ...arrrghhh!
Post by: jerryz on March 12, 2010, 05:41:51 PM
0.3mm =0.012 inch thats a big closer gap
the openers were out  of spec by onlt 0.5mm=0.002 inch thats minimal

I set openers  and closers to  LT desmo times specs.
Title: Re: Valve shimming problems ...arrrghhh!
Post by: ducpainter on March 12, 2010, 05:46:13 PM
Quote from: jerryz on March 12, 2010, 05:41:51 PM
0.3mm =0.012 inch thats a big closer gap
the openers were out  of spec by onlt 0.5mm=0.002 inch thats minimal

I set openers  and closers to  LT desmo times specs.
makes a lot more sense now.

I don't have LT's book.

What closer spec does he recommend?
Title: Re: Valve shimming problems ...arrrghhh!
Post by: jerryz on March 12, 2010, 06:02:28 PM
O.004'' on intakes  and exhaust closers .
but on exhaust side  he recommends 0.004'' on closer ans 0.006'' on openers.


My decimal point mistakes are explained by the fact that I Post from bedroom but all the data is out in the work area so I get a bit hazy.I am very meticulous normally .

I may not have enough time to complete the S4 jobs.... as monday I have to go to work in Europe for a few months and i dont have all the parts here in Thailand anyways so willl be riding in EU on the M750 for  while .
I dont like rushing valve jobs and am thinking anyway to remove heads to lap valves when i return here in a few months.
I have spare head gaskets so i can remove the heads   I like working on them on the bench its much easier ...what sucks is the cost of 4v head gaskets .
I will go outside in a while and remove the stuck collet .

When i get back here i will be loaded with spares as i have my S4 to do and a 996  and a friends wifes M900 to service.
We are thinking of setting up an independant Ducati/Triumph service shop here in the future. as there is no one within 150 miles with the skills just untrained thai shadtree mechanics.OK for stepthrus and HDs but not superbikes.
Title: Re: Valve shimming problems ...arrrghhh!
Post by: ducpainter on March 12, 2010, 06:08:21 PM
Do you remove cams and inspect rockers too?

I know you posted somewhere about replacing all the openers with megacycle rockers.
Title: Re: Valve shimming problems ...arrrghhh!
Post by: jerryz on March 12, 2010, 07:54:21 PM
Yes all cams are pulled to replace shoims anyway but i am paranoid about 4v rockers had to replace 5 ,3 years ago , but all are OK this time , got the collet out as specified , and have completed horizontal head re shim .


Going out for a beer and a shag with the mistress now , may do the other head tommorow . see you later.