New Slant Heads for 80cc's: Compression Boost!?

Yea I did what you said with the aluminum paint and it still doesnt feel/sound right. It's def. not hitting the spark plug. I was hoping it would seat better after a long run.

It just keeps raining here.
 
Mine seems to be sealed. I'm not going to recommend 17 ft pounds with stock studs, but with the higher torque and the paint, it's holding for now.

So I decided to drop the needle down - I move the e-clip up one notch. It runs WAY better. I'm cooling it now, will retorque later.

My only real problem now is getting the clutch setting right.
 
Mine got harder to start with the head. I re jeted from stock .70mm to .029 thousands of a inch. Oh yeah starts quick now. Runs way stronger than I have ever seen. The needle is on the second notch. Haven't gone to the tuned pipe yet. Might geter dun tomorrow! The bigger jet helps the oiling and really compliments the higher compression..
 
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Stock on mine was dead nuts on .7mm (0.7 mm = 2.76 mil). So you went up to around .74mm (0.74 mm = 2.91 mil). (I have a Firefox converter add-on)

I also am on the second notch. Mine is running sweet, but I need to solve the clutch issue.
 
I got the head to seal, just heat cycled it a few times, and just said screw the torque wrench and tighten them as much as I could each time I cycled the engine.

I feel liked the only place I gained was on the topend, probably 3 mph or so.

So I was attempting to tune the carb to get it running proper. My e-clip was on the very top setting and it looked a little light so I dropped it down a notch, still kinda light, another notch, and so on. I currently have it on the lowest notch and its running strong, but the plug itself still seems light in color.

Am I correct in my assumption that the top is the most lean setting and the bottom is the most rich?

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(Norman's Picture.)

If so, I guess I may have to rejet the carb to get the amount of fuel just right. I am currently running a 24:1 mix with wally world 2 stroke oil, and just bought some amsoil and plan to switch to 32:1. I dont want the bike running lean as hard as I ride it.
 
theycallmebob said:
I got the head to seal, just heat cycled it a few times, and just said screw the torque wrench and tighten them as much as I could each time I cycled the engine.

I feel liked the only place I gained was on the topend, probably 3 mph or so.

So I was attempting to tune the carb to get it running proper. My e-clip was on the very top setting and it looked a little light so I dropped it down a notch, still kinda light, another notch, and so on. I currently have it on the lowest notch and its running strong, but the plug itself still seems light in color.

Am I correct in my assumption that the top is the most lean setting and the bottom is the most rich?

Untitled-1-1.jpg

(Norman's Picture.)

If so, I guess I may have to rejet the carb to get the amount of fuel just right. I am currently running a 24:1 mix with wally world 2 stroke oil, and just bought some amsoil and plan to switch to 32:1. I dont want the bike running lean as hard as I ride it.
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Leanest
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Richest


:)

so you were right
 
i got a slant head 70cc from them (powerking), and noticed a tremendous increase of HP.
just sayin'.
 
Just ran around the block a couple times with Pablos tuned pipe right at a 12 inch header. Holy Moly.......... Two words fast and powerful!!!
 
goat herder said:
Bike Idles better Sounds cooler , and starts right up! It is nowhere near cold blooded as it was before....
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Goat Herder did you index the plug to point toward or away from the piston or did you just screw it in ?? I'm wondering if this head would benefit from indexing. TIA
 
I did bolt the head on with the spark plug at the rear of the motor. Why I figured the engine would cool internally better. Part of what naturally happens with a squish band is the air rushing away from the edges of the piston on its way up to the top has a cooling effect for the piston. The squish band is diminished on the spark plug side on the slant head. By putting that to to rear where cool air is coming in and having the heads best fins forward I think I have my best shot at longevity. Ideally the angle of the plug does nothing for these engines in my opinion. It was best suited for the plug to be dead center with a proper squish band. As for the performance on this gig still worth it to me. I have never had a china run with this much power!
 
has anyone tried the slant head on a 66cc with a shiftkit? I'm debating between a tuned pipe and a slant head. any thoughts? I've got money for both but i gotta go to college someday. I'm getting 33 mph on flat ground and up to 38 with even the slightest downhill. What can i expect from the slant head? will i get more from a tuned pipe?
 
goat herder said:
I did bolt the head on with the spark plug at the rear of the motor. Why I figured the engine would cool internally better. Part of what naturally happens with a squish band is the air rushing away from the edges of the piston on its way up to the top has a cooling effect for the piston. The squish band is diminished on the spark plug side on the slant head. By putting that to to rear where cool air is coming in and having the heads best fins forward I think I have my best shot at longevity. Ideally the angle of the plug does nothing for these engines in my opinion. It was best suited for the plug to be dead center with a proper squish band. As for the performance on this gig still worth it to me. I have never had a china run with this much power!
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Hey Goat

Did you try the head on forward first and then switch it to the rear ??

If yes than did you notice any difference in the way it ran...POPS
 
No I just stuck it to the rear. I am still studying this thing , and listening to what everyone else has done. Sorry I have not tried it that way Pops..
 
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