Author Topic: Head Bolts Stretching after bolting on HP  (Read 1555 times)

adronet82

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Head Bolts Stretching after bolting on HP
« on: June 19, 2014, 06:37:11 AM »
has anyone had issues with head bolts stretching and/or weakening after tossing on a BBK, racing exhaust and upping the main jet? My 04 laser started running nasty and sounding like i had an exhaust leak and i noticed wetness around my head...checked the head bolts and they were a little loose...went to re-torque and at 10ft lbs one snapped right off. I didnt use locktite when assembling because typically you dont use it for head bolts. A few days after the BBK install i did re-torque bolts and all was fine... after a month all was well, then i up jetted and put on the racing exhaust..couple days later the issues started......is it time for  better quality head studs or could something else be tossing things out of wack? btw I torqued all down to begin with to 15ft lbs cause i read somewhere that they should be done between 10-15...Insights please

harry

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Re: Head Bolts Stretching after bolting on HP
« Reply #1 on: June 19, 2014, 05:35:14 PM »
heat is the only thing that happens  it could change the temper/hardness
 i don't use a t.wrench much on head bolts anymore i just use a 3" stubby ratchet
 never in 10 years and  a couple hundred kits and rebuilds has that happen to me.

oilyhans
 
i own a scooter shop  with rentals ,sales& racing parts.
i also appraise scooters for KBB.

2003 Vino classic stage 0.75
de-reged stock variator w/8g sliding weights.
1.5k rpm  springs
42mph
2005 veniceLX ~70cc~upjet~1.5k rpm springs & 7gr sliders
46mph
KeyWest de restricted~8gr slide

adronet82

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Re: Head Bolts Stretching after bolting on HP
« Reply #2 on: June 20, 2014, 09:42:10 AM »
yeah me and my bad luck i guess...ima head to fastenal this week and find me some new quality studs. i prolly just ended up with a worn out abused scooter when i bought this last year. when i installed my bbk this spring i did notice a little chunks missing from top edge of old piston which explains my low compression before. now how would a chunk go missing from a piston? worn out and abused!

adronet82

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Re: Head Bolts Stretching after bolting on HP
« Reply #3 on: June 27, 2014, 10:24:56 AM »
Looking for the cylinder studs seem impossible...tgb diagrams say m6x100 yet I can't find anywhere online that sells and nothing local that can get their hands on....is this the right size? Can anyone help locate some for me??? Pls help

harry

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Re: Head Bolts Stretching after bolting on HP
« Reply #4 on: June 27, 2014, 10:27:48 AM »
dude, i'm a TGB dealer
so problem solved

oilyhans
i own a scooter shop  with rentals ,sales& racing parts.
i also appraise scooters for KBB.

2003 Vino classic stage 0.75
de-reged stock variator w/8g sliding weights.
1.5k rpm  springs
42mph
2005 veniceLX ~70cc~upjet~1.5k rpm springs & 7gr sliders
46mph
KeyWest de restricted~8gr slide