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Discussion Starter #1
Well i was browsing the web last night ,and found this site that sell's a complete head assy...for the triple 700's SITE: www.moutianperformance.com/yamaha_engine_mods.htm..

could someone give me your opinion's on this product ..good or bad!,and also would add that NOT looking for more perfomance out of this product..looking to fix my detonation problem..Even the the hp gain is nice,but for 300+ it's not worth the money..It's worth the money to fix my spark nock problem though...

rather replace the head one time! :thumbsup: then the piston's in a trail head(Parking Lot) :cussing:
 

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Are you running high octane fuel ? Are your carbs clean ? Was the head gasket trick done to the sled ? Whats the jetting at ? The head is nice but its more for MT riding were they run very lean and high compression. I remeber you can get that head in a 3 different configs. One is almost like stock. In the midwest we just would remove the middle layer or two layers of the head gasket but you have to run high octane fuel !!
 

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Ive seen your last post so you are running high octane . But the carbs need to be cleaned and sycn'd sometimes. The jetting isnt the same across the board I think the first cylinder is a bit fatter. Ask a dealer about jet sizes they should set you up with the right ones . The stock is way to rich. Do you have the stock reeds or carbon fiber . Check the reeds, if carbon fiber they can break over time.
 

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Discussion Starter #4
bone daddy
I think i found the problem friday night..took it to shop (work) ,and decided to take the head off to see if it had hot spot's on the head/piston causing my problem or if it was an ignition problem... come to find out the #2,And #3 (cylinder head combution chamber's) had pit's in it...(causeing preignition)

so took it over to the mill table to meassure the specs/(CCed) all 3 combustion chamber's to see if it could be cleaned up to smooth the high spot's..AS luck would have it!!! i took .003 off of #2 ,And .005 off the #3 combustion chamber's.. all 3 chamber's are a true 23 cc's.. (stockhead gasket).. TOOK 5 HOUR'S...Also reshimmed the head gasket that was on the tottol yamaha site useing 1 paper gasket to up the compression...NO DAMAGE to the piston's..smooth as glass!! cleaned up the carbon w/part's cleaner(part's washer)...
carb's were cleaned all passages were clear..nothing blocked...the man i bought the sled from said he drained the carb's every season,and used WD40 on all internal part's of the carb's...they are very clean from my inspection..They look brand new internaly !!!
also cleaned/polished the exhaust valve's..probable not a big deal to polish the exhaust valve's,but it only took 30 minute's to do it..NO BIG DEAL!!!

0 to 3500 ft trail
AS for the spec's on the carb (carb's) I ran it with the the bender setting's for 0-3500 ft
1. pilot jet's: 52.5
2. pilot fuel srew's :1.5 turn's out
3.main jet's 0 to 35 degres(temp)
4. jet needle clip: PTO#3,CENTER#4,MAG#3
also running carbon tech reed's

CLUTCH SETTINGS
1.0 to 3500 ft setting's for trail
1. primary spring WH-SIL-WH
2. weight's stock 8CH
3.rivet's stock
4.roller's stock
5.sec spring stock
6.spring twist 60 DEGRES( LAKE)
7.helix 977TP
8.gearing 22-40 (TRAIL) STOCK 23-40
9.shim's 4 pc's
also not sure if i should run premium with an octane boost??? with the bender pipe's/other mod's it recommend's 92 octane,but! with just the head shimming from tottol yamaha they recommend 92 octane w/ stock pipe/stock can...so should i be running 92 + octane boost (for trail's),And racing fuel like torco or turbo blue (for the lake's)???
 

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Discussion Starter #5
Are you running high octane fuel ? Are your carbs clean ? Was the head gasket trick done to the sled ? Whats the jetting at ? The head is nice but its more for MT riding were they run very lean and high compression. I remeber you can get that head in a 3 different configs. One is almost like stock. In the midwest we just would remove the middle layer or two layers of the head gasket but you have to run high octane fuel !![/b]

bone daddy!
I did all the above to the sled as you mentioned.mains jets (2-3cyl)150,piolet jet's 52.5(all3)fuel mixture's 1.5 turn's out,also did the gasket trick to:(save money).. last weekend I used 1 paper gasket ...seem's to run fine with 92 + octane at -05 F. jetting at this temp seems to be optimum..also recived my new 1.125" (Shotgun) track to day! so that project is on going this weekend...seem's there will not be any snow for the weekend to run the new track....so I guess i'll have plenty of time to tinker removing heat exchanger pertctor's for more clearance,And putting new 1" tunnel pertector's under the tunnel..also putting 192 1.175" studs in the track...also recieved 8 tooth drive wheel's from ebay today..so I think I'm all set on part's for the project/upgrade..new bearing's also!
Any thing i missed?? please let me know!!!
 
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