[quote]
Originally posted by: Duneaddict

DA: 1st complaint is it's pretty thick... It's a great theory, and would work well, but my jug needs to be milled before it will seal, as it is warped just enough to cause problems. I tried getting it to seal 5 or 6 times at the dunes last year... got tired of working on the thing, so put a cometic back in...I've never been that happy with cometic either... genuine suzy is the best, but they don't make an oversized gasket for the larger overbores.
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DG: I never did like a thick head gasket.. not even on a car engine.. I always go for the thinnest ones I can get because it helps raise the compression some by using the thinner gasket.. I have an overbore so I know what you mean there with the Suzuki gaskets.. I have a .140 overbore....
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DA: Gotta use some 3bond or equivalent sealant to make any gasket seal on the mighty 500...
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DG: Yeah kinda figuring this out.. My other gasket never sealed either.
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DA: Another thing to think about is: is it an '87? If so, they have the tendancy to not hold torque on the head studs. The real fix for this is to install larger studs. (Two options here, have a machine shop install 3/8 studs, or get the 88+ head studs which have a 10mm to 8mm taper)
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DG: This motor already has the 10mm to 8mm tapered studs. I wonder why they tapered them? Wouldn't it be better to run straight 10mm studs? I am thinking about putting straight 10mm in mine and machining the head to accept them... I am thinking about taking my head and cylinder into work with me one day and checking them to see if they are flat. I can machine them out on my lunch break.
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DA: ALLCOOL is right, while you've got the head off, study your piston wash and see what's happening. Jetting isn't rocket science, but it takes a little practice to get it right... You can do it!
Be careful comparing mikuni and keihin jets... unless your measuring actual oriface size... because they use a different numbering system.
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DG: Yeah I know they are numbered different I checked them with gage pins and that is how I know the Mikuni was smaller.....
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DA: Sure can't wait to see that texas thong! Especially posing with the mighty 500! That's centerfold material right there!! *Evil grin* Keep up the good work!
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DG: Now I dunno about all of that... I think I need some help in certain areas to be "centerfold material" but thanks anyway..

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DG: I'll definately agree on head gasket thickness... The thinner the better, however I've machined my head to compensate for the thicker gasket... my comp ratio is pretty high... The next time I go in to do some work, It'll be O-rings...

That tudors copper head gasket would be great depending entirely on flat mating surfaces..

Not sure why they tapered the newer studs... guess the engineers figured there is enough strength in the stud itself at 8mm, just not enough holding pressure with the smaller dia...
I basically used a 3/8 stud and machined out the head to accept the larger dia. (Watching the $$ for other mods)

I think the poster idea is a very good one... could be fairly lucrative also!!! I'd buy one!

 

Well I got the studs fixed in the head... I went to a straight 10mm stud. Took the head and machined it out to accept the bigger studs and did a little milling on it to make sure it was flat, didn't cost me anything since I did it myself... [img]i/expressions/face-icon-small-wink.gif[/img] We will see how it turns out...

OH the poster thing lemme see what i have to do as far as getting a picture to keep the resolution for the poster size and you never know I might make some...

 

Hey dirlgirl still waiting on my picture [img]i/expressions/face-icon-small-smile.gif[/img] Thats a good looking quad you have there looks just like mine!(Ha Ha) I just call Duncan Racing about the same problem i was having they have mailed me all the jets and needles that i need to get it right i will email you with the info they gave me!

 

I know.. [img]i/expressions/face-icon-small-sad.gif[/img] I gotta get the Zilla back together again... You know it got rolled last weekend.... Didn't do a lot of damage, bent the bumper and steering stem - plastic got scuffed but it isn't bad.. Tore up the carbon fiber graphics on the back fender though... Nobody got hurt either..

 

Glad you're okay! That 500 is a beast...

 

I started checking everything out on it and noticed one of the ball joints was bad and the upper a-arm bushings, so I spent $375 getting all new stuff for the frontend and after I got it all back together I went to kickstart it and try it out and the stupid kickstarter stayed down... So instead of riding, I spent Saturday tearing the side cases off of it and fixing all that stuff. Got all that back together and rode it Sunday - it handled great and ran nice but now the water pump seal is leaking AGAIN! [img]i/expressions/face-icon-small-mad.gif[/img] This is the 3rd one of those I have replaced! I am guessing the shaft is bad. So far I am getting one ride out of it for every $300 I am spending on it. I hope it gets better than that... [img]i/expressions/face-icon-small-disgusted.gif[/img]

 

Thats one expensive toy you have there, when you water pump seat goes bad does it leak water or oil from that cover? Mine just started this weekend leaking oil from that cover but no water!???? [img]i/expressions/face-icon-small-disgusted.gif[/img] So i guess i will have to fit that now!

 

Is your LT an 87 or an 88 up?
Zillarider02's 87 has the Keihin carb, 60 pilot, 180 main, 3 clip from the top @ 900 ft altitude. The 180 is a little rich for safety sake.. This is with 40:1 premix. His carb is a 39 bored to 41.5
I run 62 pilot, 175 main, 2 clip from the top on the 89 Zilla. Both motors are ported quite extensively. My carb is a 41 pro series.

Use copper coat on both sides of the head gasket and Permatex "right stuff" gasket sealer on the base gasket in the area of the reed cage. This has been VERY successful for us.Picture of gasket sealer

Oh, I might add there are 5 Zilla's in our riding group now.......

 

Hey truckracer how much diffrence did the 13 front sproket make on your predator i just bought one last week and thats what everybody is saying to do?????????[img]i/expressions/face-icon-small-shocked.gif[/img]