spark plugs coming loose

[05Special]

I've been there, find the problem.....It was very expensive when i decided not too...I'd definitly back the timing down a bit...your motor is telling you something is wrong...

[yamaha11]

i had the same problem with my passion 4mm. and i was only runnng 4degress of timing and i was running race gas. the one fell right out. but know i have a different set of ported cylinders and still the 4mm and no problems. i think it was my domes from what the other builder told me.

[bebetekbanshee358]

Can someone tell me if when sparkplugs get loose - if its a problem with not enough octane or is it a problem with too lean of a jet?

 

thanks

 

 

locktite ur spark plugs... ..check it out before a $2.50 spark plug causes some major damage.. x2 on the domes and timing. bring it down brotha...

[camatv]

7 d is too much on a gas motor. put it to 4 and leave it alone..

 

the domes in a cub have to be over .40-.45 tho squish clearance, might even have domes for a different angle in there AKA blaster piston on banshee angle dome..

 

you MAY have poped an o-ring on the compression side and its leaking coolant in to the cylinders,, doubtfull but its the result of deto, timing, octaine, bad dome match, air leak etc etc on cubs.

[AKheathen]

sunoco says that gas is good up to 13:1 compression but im thinking i might need something rated for more compression since im mixing the fuel with oil...

 

can anyone help????

well, that's up to 13:1 and based on a 4stroke aplication, which this is not

 

the domes in a cub have to be over .40-.45 tho squish clearance, might even have domes for a different angle in there AKA blaster piston on banshee angle dome..

x2, you definately should know the squish clearance and band/angle. going a little more conservative can solve deto problems, and mabey a little sacrifice that you wouldn't notice. I push the octane limits pretty far by running all the way up @ .052" clearance. also, what range is it set for? topend power? mid-top? perhaps, you don't need so much compression or timing. it could yeild better by turning it down, but that's what was suggested for a reason.

 

 

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28-July 09 Posted 14 February 2010 - 03:06 PM

 

yes im tightening them hard enough...

 

im runninig an uncorrected 12:1 compression ratio with 7 degree timing advance.

i run sunocco 110

 

that gas is leaded/unoxygenated and 105 MON, 110 (r+m)/2

well, then that is not really "110" by the math. perhaps that is a problem.

also, make sure you do not over-tighten the plugs when you put them in. if you over compress the ealing ring, it can just streatch the treads out when it heats up. follow the directions of the plug-i think only 5/8 turn after it hits the seal ring

[Ieat4strokes]

7 d is too much on a gas motor. put it to 4 and leave it alone..

NOT necessarily! I sent my whole motor to Jeff at FAST and thats what he set my timing on my 4mill at +7. Ive been running c12 but Im switching over 2 Sunoco 110, got a 5 gl jug full now, havent ran any yet to tell if thats the guys prob or not.

[Alex29573]

let me know how the sunoco 110 turns out..

 

i spoke to vp racing today and they recommended c12 or vp113. they said vp110 would probably work as its better than sunoco 110 but that c12 and vp113 are overall better fuels.

 

still waiting for passion racing to call me back.

 

thanks guys

[RadarRacing]

Throw that plug lock away. IMO. To answer the other part of your question lean jetting can absolutely cause detonation. I know guys that run their bikes kinda rich and run 7 degrees all day but on a gas motor jetted perfect 7deg is usually too much to run more than one or two hard passes. if your burn ring on your plug is .080 tall then you are jetted plenty rich to run 4 to 5 degrees. You should probably keep an eye on your water temps I'd bet its detonating once hot.

[FrankieSquid]

I had my sparkplugs come loose when riding. For me it was just a vibration issue nothing else. I remember seeing a billet bracket type of thing where it hold both the sparkplugs in place preventing it from coming loose i just dont remember where. I just forgot to tighten them really good. This is if you not having mechanical issues.

[papa_smurf49319]

jim at passion also told me plus 7 on the timing, havnt really got to ride it yet due to winter, but we will see when i pull it out.

 

 

 

Cody

[sheefreak]

Mr squid, the thingy you are talking about is a plug lock. It has been mentioned earlier in this thread multiple times. Do not run one!!!

[AKheathen]

plugs don't just come loose on vibration. other than deto, it would only happen from overtightening and/or thread damage