11:1 piston with sparks key

[quadmanw]

Anyone ever have any problems with running a high compression piston and the sparks timing key? It's not recommended but it shouldnt really matter? I have no clue.. Don't want to blow my brand new top end lol

Thanks, Steve

[jkosakowski]

The main reason they say not to is because of the heat it causes. I think the sparks key advances it 6 degrees which would definatley increase your temp. It might cause your head studs to pull or you head gasket to blow not positive though. I don't know if i would try it.

[quadmanw]

I don't really feel like putting the stock one back In haha. Well I have a large oil tank and if I get jetting perfect it could help a lot.. Maybe I should take it out..

[Drfat400ex]

Alot less work putting the stock key back in then it is rebuilding after your piston melts. ;)

[quadmanw]

Very true! I guess the new rebuilt motor will make up for that throttle response ill lose taking the key out anyways.

[Drfat400ex]

Do you really get anything out of an advance timing key? I hear about throttle response, but that's what people say about something they bought that really has no purpose. If they accually do something I think I might get one.

[quadmanw]

When I put mine in I got a little better throttle response and the bike was a lil more jumpy. Huge improvement? No. Worth $20 and a half an hour.. IMHO, yes. That's just my thoughts

[CJM]

Dont do it, do the piston and remove the key

[Drfat400ex]

Originally posted by quadmanw
When I put mine in I got a little better throttle response and the bike was a lil more jumpy. Huge improvement? No. Worth $20 and a half an hour.. IMHO, yes. That's just my thoughts Yeah I'll have to look into one, maybe get some air scoops with it even out the temp a small tad haha.

[CJM]

Put the key in a buddies, it honestly didnt feel different to me.

[Stickman400]

Somebody on here sells +3 keys that you can use safely with a 11:1 piston. Idk if he has anymore right now tough.

[quadmanw]

I have to look into that. For som reason I thought that my sparks key was +3.. I'll just take it out. I don't want any problems haha

[Pipeless416]

i had an 11:1 piston and a +6 key combined for about a year and a half with no problems. i also have a stage 2 HC though so that changes things a bit. i never even had problems in 90+ degree weather. i took it out to be safe, and i didn't even notice a difference.

[quadmanw]

That relieves me.. Hahaha

[jkosakowski]

Pipelss how did you like the 11:1 with a stage 2 mine is getting built right now and am curious?

[Pipeless416]

Originally posted by jkosakowski
Pipelss how did you like the 11:1 with a stage 2 mine is getting built right now and am curious?

its a very common setup that most people seem to be very happy with. it pulls very hard off idle, but i think that is mainly due to the 450r carb, but it seems to never stop pulling up top either. i'd say most of the power is in the midrange which makes it very ride-able. if i were doing a build right now i would do the same thing over again.

[jkosakowski]

Was it stock bore?

[Pipeless416]

Originally posted by jkosakowski
Was it stock bore?

87mm

[CJM]

416 and stage 2 is the way to go imho. Ive ran it and now run a 426, 426 has slightly more power.

In all honesty I were to do it again Id run a 407 11:1 and stage 2. The bore doesnt make the power really, its the compression. Stock comp ratio is 9:1, 11:1 is quite a jump.

[quadmanw]

That's what mine is getting built right now. High compression, low bore engine lol

[CJM]

What I like about the smaller bore size is if you need to bore it again you can do so. After my 426 its 440 or go back to 416 or 426 with new rings or something.

[quadmanw]

The small bore motors are a lot cheaper than going 440 also as you know haha