quadgod211 Posted April 26, 2009 Report Share Posted April 26, 2009 (edited) got to run my bike tonight for the 1st time this season..... track wasn't to good,,it was real dry ran 4.20@74mph w/60ft 1.52 on motor about mid track my left leg gets drenched in warm water........ i take it back to the pits and fill it with water agin and start it up to look for leaks and my overflow tube at the radiator cap is blowing water like a pressure system.... is this a oring blown and do you guys think it was my 190 conp that done this ??? i ran my timing at +7 and my plugs was dry..clean but dry...could i have been detonating maybe??? how could i have heated the oring enuff to blow on methanol?? i need to get to the bottom of this before i spray the bike........ matt Edited April 26, 2009 by quadgod211 Quote Link to comment Share on other sites More sharing options...
rubberneck Posted April 26, 2009 Report Share Posted April 26, 2009 Definitely sounds like blown oring. What do the plugs look like? Are they showing signs of heat on base of threads around the ground strap? Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 26, 2009 Report Share Posted April 26, 2009 sounds like a bad oring or a pinched one. Pressure test the cap while you're at it, just for shits and giggles. Quote Link to comment Share on other sites More sharing options...
23champ Posted April 27, 2009 Report Share Posted April 27, 2009 I had the same problem a couple years back after I switched to a different set of domes. I kept burning the o rings up. I eventually found the problem to be my domes werent seating properly on my cylinders. The lip on the bottom side of the dome wasnt tall enough causing the combustion to seep past the aluminum sealing lip on the dome, and burn my o rings up. I was running a vitos hemi head and trying to run noss domes, which are supposed to be "interchangeable" (well, noss and pro design are interchangeable, and vitos and pro design are interchangeable, so I figured it would work...it didn't). I ended up having to send noss my original vitos domes, he figured the problem out and custom made me a set of domes that would work. Havent had a problem since. Quote Link to comment Share on other sites More sharing options...
quadgod211 Posted April 27, 2009 Author Report Share Posted April 27, 2009 it was the brown dome o ring on the left side..... found out that the cheap acorn nuts had all stripped on that side so im guessing that blew the o ring..wouldn't you guys think???? my plugs was dry but in good color....i noticed my bike wasnt smoking that great off line so i might have been a tad lean...im turning the powerjets up next sat maybe the track will be a lil beter ,everyone said it was around 2 tenths slower sooo i should be in the 4.0's atleast if my 1st run was a 4.20 with no tune.... matt Quote Link to comment Share on other sites More sharing options...
2slow350 Posted April 27, 2009 Report Share Posted April 27, 2009 it was the brown dome o ring on the left side..... found out that the cheap acorn nuts had all stripped on that side so im guessing that blew the o ring..wouldn't you guys think???? my plugs was dry but in good color....i noticed my bike wasnt smoking that great off line so i might have been a tad lean...im turning the powerjets up next sat maybe the track will be a lil beter ,everyone said it was around 2 tenths slower sooo i should be in the 4.0's atleast if my 1st run was a 4.20 with no tune.... matt Sounds lean to me, maybe back the timing down to 5 or 6 degrees.. Jmo Quote Link to comment Share on other sites More sharing options...
quadgod211 Posted April 27, 2009 Author Report Share Posted April 27, 2009 so your saying that its lean and thats why the o ring broke...or im just lean period?????? the head nuts on that side was near finger loose....at first i thought it could have been were the oring was gone it made space for the nuts to loosen....then while re torquing 3 outta 5 nuts wouldnt tighten down at all... put new normal style nuts on and it torqued down great..ill do a comp test agin in the mourning and see if im all good..... matt Quote Link to comment Share on other sites More sharing options...
J-Madd Posted April 27, 2009 Report Share Posted April 27, 2009 I've had problems with the acorn nuts many times...the threads will come out when tightening to torque spec. It seems that the studs are sometimes too short, or the head is milled too thick in the area around the studs. Quote Link to comment Share on other sites More sharing options...
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