70cc bogging down at full throttle?

[pianoman8t8]

I just got a 70cc motor, and so far i've put around 20 miles on it, but it seems to bog down when i give it full throttle. It seems to go fine just below full throttle, but i was wondering if there was a way to adjust it or fix it so it either stoped bogging down or performed better without bogging down at full throttle.

 

[etheric]

Ours did too.
We tried a few different things, with no success.
We are remounting the engine though, so the new bike will be our test ground for removing that fullthrottle bog.
We were still running 20:1 though, so on the new ride we'll put in a new plug and a new mixture and see what we can come up with.
A plug chop will be first in order on the new bike, as going fast will be our goal with the new ride (the AMF was more of just a cool looking tester)

 

[gone_fishin]

hi, pianoman8t8, welcome

i think trying to push a full throttle so soon won't give you what you're looking for, search thru our "general discussion" and "technical help" areas to find a whole bunch of good info on break-in theory.

 

[etheric]

^^^I agree with Augi^^^

I think breaking it in definately takes priority over it bogging while you are doing something that you may not even want to do.

BTW, ya sneaked in, Welcome.

 

[Steve]

My 70 cc would also bog under full throttle until I opened up the idle mixture screw an additional turn. I know, it's supposed to effect the idle, but mine also effects the WOT mixture.

 

[andrewflores17]

my has been doing the same thing when i go full throtle and its broken in and i run it on 32:1
i just ordered a 36 tooth sprocket hope this makes it stop boging heard what sounds like miracles from other who got the 36 tooth sprocket

 

[Tom]

Mine would do that, it was a blown intake manifold gasket. I made another one out of a cereal box, put it on and it made a world of difference.

 

[azvinnie]

hay guys, l just spoke with roland from spookytoothcycles the other day about this same problem, and it fixed it. it only took 2 min. in your carberator there is a pin(long and thin) and it has a black ring, if you look close at it there is 3 postions the black ring will slide on to the pin. 1, 2, and 3 little grooves. mine was at the 1st position and changed it to the 2nd position and my boging went away, here is a pic ,but its best to look at yours........good luck

sorry about the crappy pics

 

[Guest]

If it bogs down, as you found out, it is the mixture.

As for not going full throttle on a new engine, that is bad advice. You should take every opportunity to exercise the engine's full rpm range to get a proper break in. If you don't put the engine through its paces, you will never develop sufficient cylinder pressure to seal the rings aginst the piston wall. Also, connecting rods stretch at increasing rpms. If you drive slow the rod won't strech and allow surface mating to occur at those locations where the piston goes when it is revving high. What happens is the cylinder ges mated to the cylinder for only a small portion of its intended travel and when you rev higher you actually cause excess wear from the portion of the cylinder that is slightly smaller in diamter than the rest of it-a taper.

I can go on but too many knucklehead with no engineering degree to back up their knowledge base.

 

[gone_fishin]

I can go on but too many knucklehead with no engineering degree to back up their knowledge base.

is that your "educated" way of volunteering to be technical moderator?

in 5000+ posts, i have yet to see anyone claim to be an authority on these chinese engines, 'specially not MBc staff...that's why we built this forum, you "knucklehead"

too bad you didn't bother learning any manners while you were becoming an obvious expert on engines.

yup, i admit i took your remark personal, i think you're expecting too much from a bunch of self-avowed novices...your really good info would have been just as useful without the insults, imo