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THUMPTHUMPTHUMP 12 Feb 2016 18:43

gasket thickness
 
how thick is the stock xt600e head gasket?

*Touring Ted* 12 Feb 2016 19:17

Compressed or pre-compressed ??

You looking to skim your head or play with the compression ratio ?

THUMPTHUMPTHUMP 12 Feb 2016 19:48

I put a 11.5:1 piston in. Used a namura metal head gasket. thickness unknown. I need to lower compression and prevent weep or blowout. Namura weeps but may due to knock. I have knock even with premium and octane booster when at full throttle mid-range .Thought I should try a thicker head gasket.thumpthump

pete j 13 Feb 2016 07:01

Hi TTT,
New genuine gasket (1JK-11181-02) with pressings is 1.5 mm. Total thickness of laminates is 0.6 mm. Compressed thickness should be close to that. Regret don't have a used one.
best,
p

jjrider 13 Feb 2016 12:18

I had to go out and look at my copper gaskets I waterjet out . I had taken a used gasket to get the copper thickness , .048" is what I came up with . I had to get .043" copper because it didn't come in the .048" size. .062" would be a good thickness to get then to try and reduce compression. 2mm may be what you can get .

THUMPTHUMPTHUMP 15 Feb 2016 03:17

thanks, thats what I needed. thumpthump

THUMPTHUMPTHUMP 20 Feb 2016 13:53

I ordered a 96 mm with .063 thickness. I wonder how much it will drop the compression? Should I put this in dry or spray it with copper gasket spray? thumpthump

pete j 20 Feb 2016 15:54

'To measure is to know':smartass: I've not seen combustion chamber volumes for the XT, even for standard setups.
Bigger pistons seem to come with known compression ratios, so someone must have done the maths.
As the piston protrudes into chamber one can establish volumes with gaskets of known thickness, or without a gasket using water and a burette. Use light oil to seal rings and valves and vaseline on head to cylinder joint.
XT aperture is round so easy calculation with different thickness gasket.
Never done this (to XT) but should work.
Another thing; how about adding thickness to the cylinder base gasket experimentally to test pre-ignition? Minor change to timing but that should'nt
matter.

turboguzzi 22 Feb 2016 18:04

things get tricky with high compression.... just adding gasket height will also cancel any squish effect you have in the flat fore and aft areas. not good...
you should measure how muc squish you have now. if you are round 1mm, it's good, lower your compression just by machining the crown.

there's a good vid in motorcyclist online now on how to do it

http://www.motorcyclistonline.com/mc...uish-clearance

THUMPTHUMPTHUMP 8 Mar 2016 03:27

Well I just guessed and went with the .63 and it worked out . No more knock and just prem. gas. no octane booster. power is still great but no full throttle heavy load knock issues. THUMPTHUMP

jesse_madden 18 Mar 2016 13:30

Where abouts did you order the thicker head gasket from?

N67 23 Aug 2017 09:54

Hi everybody : )

soon I will have to remove stator cover to replace very tired starter clutch on my XT.
I have quite a big amout of this hi-performance gasket which I've successfully shaped and used for the clutch cover as well as for the starter reduction gear cover on the opposite side:
http://www.klinger.se/images/Produkt...sil-C-4400.jpg

The main point here is thickness - 1.5 mm, which is way greater than oem (maybe less than 0.5mm).
and, using this gasket will shift the stator coils and pickup magnet outside from the rotor, 1mm at least..

so, what do you think, do I have to stop thinking about using this stuff?
how much is 1mm for pickup? (I think that for stator coils it might be ok)

good point about this gasket (except quality) is possibility of re-using in the case of trouble.
and, also, instead of ordering that thin one, I will have chance to have more bier
: )

Jens Eskildsen 24 Aug 2017 07:03

I have 2 gaskets on that side on mine because of a cracked statorcover that has been welded. Its not an issue, or atleast it havent been for me.

N67 24 Aug 2017 11:23

Thanks Jens, sounds like a good news : )

Meanwhile, I've already removed the cover and checked these elevated "steel markings" on the outer circle of the rotor. they have different length but width is at least 7mm for all. and magnet head of the pickup coil has 3-4 mm diameter.
So, I guess that there should be a possibility of shift 1-2 mm on each side according to the assumption that by default (i.e. using standard gasket) these markings and pickup head are centered.

Your experience + these observations makes me feeling safe that all that cutting process of gasket (it takes hours...) will not be in vain.
especially I have one more backup plan for the worst case (discovered right after looking inside the cover :rolleyes2:) - using specific sized washers under stator and pickup coil in order to counterbalance the shift caused by the thick gasket.

:mchappy:

N67 17 Sep 2017 19:55

1 Attachment(s)
as an update after couple weeks and couple nice trips (~1k km) - having
this thick gasket on the both sides of engine, under clutch cover and now under alternator cover as well. it works fine, no issues with the functions of stator/pickup etc.

I've attached vectorized .ai and .cdr versions of the shape of gasket.
it might ease someone's job.
but still not a perfect shape, started with paper and pencil around actual cover of mine.
advice to keep at least 1mm out while cutting and then adjust accordingly.


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