Cant get my exhaust valves perfect....

paramuir · Jan 27, 2010

OK so i know i would love to have them shinny like a mirror...but this isnt going to happen..in the end how clean should they be...mine have some pitting on the bottom which i know will just carbon up again...

thoughts....tips?

Danbot · Jan 27, 2010

Oven cleaner, and lots of it!
Short of taking them to a bench grinder with a wire wheel, I think the oven cleaner does a pretty good job. The less scratches you can leave the better.
In my mind, they need to be cleaned at least once a year anyways, probably twice, get them as good as you can and chuck em back in!

SwitchbackRick · Jan 27, 2010

I just finished doing mine...had the same problem...the oven cleaner got the top layers off, but found if I soaked them in break cleaner, it got right down. Still a little pitting and carbon. Letting them sit over night next time. How tight are the gilotines supposed to be in the bore?

05900 · Jan 27, 2010

A fairly snug fit but they must slide easily also replace springs if it has been a while.
Clean as possible and smooth but a mirror finish is not necassary.

otterpoo · Jan 28, 2010

Valve spring ?

Is it wise to replace stock(purple) valve springs with higher elevation springs in a bone stock 05 900? I ride at sea level. Would this have any use for me or be negeative on my engine? Thanks.

river · Jan 28, 2010

these exhaust valves are know to not stay fully open at wot .I added a seal in mine and drilled other holes and now they stay open a wot. with the stock spring.I had pic but cant find them.

t hillrider · Jan 28, 2010

river said:
these exhaust valves are know to not stay fully open at wot .I added a seal in mine and drilled other holes and now they stay open a wot. with the stock spring.I had pic but cant find them.

River can you elaborate on this please. Sounds like this might be my problem running WO. Ive had this suspicion for a while but am not able to prove it. Any ideas on how I could tell if the valves are not staying open at full throttle ?

Danbot · Jan 28, 2010

Run it on a stand with the hood open, you should be able to see the "nipples" on the bellows nuts protrude through the hole in the black plastic caps.

Or you can plug the VES hoses from the valve bodies, and take it for a run. The VES solenoid can get gummed up and not fully seal, this test will bypass the solenoid. (you can also watch the nipples on the stand with the plugged hoses for comparison)

Hope this helps, Dan

otterpoo · Jan 31, 2010

DiscoDan said:
Run it on a stand with the hood open, you should be able to see the "nipples" on the bellows nuts protrude through the hole in the black plastic caps.

Or you can plug the VES hoses from the valve bodies, and take it for a run. The VES solenoid can get gummed up and not fully seal, this test will bypass the solenoid. (you can also watch the nipples on the stand with the plugged hoses for comparison)

Hope this helps, Dan

Is it advisable to leave the hoses to the VES plugged permanently?

overkill131313 · Feb 1, 2010

so pull the hose off the VES and just plug it? and plug the nipple on the VES or does it need to breath?

otterpoo · Feb 1, 2010

overkill131313 said:
so pull the hose off the VES and just plug it? and plug the nipple on the VES or does it need to breath?

8) Plug the exhaust purge hoses coming off the exhaust valves, this makes it like the 2001-2004 set-ups and definitely improves acceleration by allowing the exhaust valves to open sooner. An added benefit is the hot exhaust that was "held back" in the engine is released sooner, thereby effectively reducing internal engine temps.

I found this under Increase Your IQ.

I disconnected the two hoses from the exhaust valves at the T connector before the silenoid hose and blocked them off using a 5/8 bolt with the head cut off with two O clamps to help them keep together. The two ends come together at the ends and connect to the VES. The silenoid hose just let empty into the engine bay.

I have not really had a chance to try this out yet to tell if it had any effect on performance. I did take it on a very quick run on the lake but had only shore snow drift to play on. You can't get anything in a short distance with these 900's.

paramuir · Feb 3, 2010

anyone done this yet?

BIGGDAWG · Feb 3, 2010

paramuir said:
anyone done this yet?

should be riding mine tomorrow night with mine plugged. cross your fingers for me. hope it runs good going to try for a 30-40 mile trail ride to the girlfriends house :face-icon-small-hap

jskattum606 · Feb 4, 2010

Let us know how this works. Interesting

Danbot · Feb 4, 2010

Ive tried it, and posted my results in the original thread over in the IQ sub.
Elevations from 3000 to 8000 feet, and conditions from deep and dry powder to hard packed trails. I find the engine revs up a bit quicker with the hoses plugged, and you can tell by exhaust note that the valves are capable of partial opening making them more of a "ves" than stock. It just felt all around more peppy and responsive to me.

paramuir · Feb 5, 2010

so in the end you left it pluged like this?? any long term hazards to doing this?

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Cant get my exhaust valves perfect....

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