Engine Trouble 80cc cutting out at higher rpms HELP

[gary55]

It has 350 miles on it. My exhaust is lengthened with the stock muffler that has been 'cleared out' a bit. I thought this new carb gave the proper amount of fuel being that it doesnt have an adjustable needle like the stock one. I dont remember changing fuel. Maybe i need some fresh since i hadnt run it in several months....?

Can i use the CDI coil i posted?

Start with just changing the fuel. If it has been sitting for several months It may very well have gone bad. Then work from there.

 

[crassius]

before working too hard to find the problem, take bike back to way it was when it ran well - put back old carb, old muffler, whatever - then see how it goes

 

[scorpion1]

before working too hard to find the problem, take bike back to way it was when it ran well - put back old carb, old muffler, whatever - then see how it goes

It started doing the cutting out exactly as it is set up now but with the old carb. I noticed something wasnt right and checked the carb and the float was half full of gas. Thats sorta why i bought the new carb.

 

[scorpion1]

Idk but I'm sceptical about bikeberry products being any different to stock, lol.
37mph doesn't actually mean anything without knowing what your gearing ratio (sprocket and wheel size) is.

All I know from my experience is that filing the magnet key by 1.2mm (1mm should be fine too) to retard timing is working nicely for me.

I'm using the stock CDI and I have been trying to take it easy, only once been tempted to go to 8000rpm (which is 37.27mph on my bike) but I'm still breaking in so four stroking all the time except on steep climbs.

Filing the key is certainly the best value for money because it's free! So I recommend you try that first before spending money on a CDI.

Offset timing by magnet key

• FurryOnTheInside
• Sep 17, 2017

1.2mm offset key for a 5.4° postponed base timing (if I'm correct).

Can you tell me or show me in the pic how to do that? I would prefer retarded timing. I've 10* before dead center(?) is good

 

[scorpion1]

I hate to sound repetitious but does my Bike have a CDI now?? Its the stock China 80cc kit. If i decide to get the one i posted will it work??

I'm asking cuz I see them listed as ignition coils.......then some as CDI's. Is there a difference?

 

[Street Ryderz]

I hate to sound repetitious but does my Bike have a CDI now?? Its the stock China 80cc kit. If i decide to get the one i posted will it work??

I'm asking cuz I see them listed as ignition coils.......then some as CDI's. Is there a difference?

Yes you have a cdi now and yes the one you showed will work but as Furry said it's just a stock cdi with a replacement wire and boot.You can buy the NGK wire and boot from any good bike shop and fit it to your stock cdi.

 

[Street Ryderz]

It started doing the cutting out exactly as it is set up now but with the old carb. I noticed something wasnt right and checked the carb and the float was half full of gas. Thats sorta why i bought the new carb.

Did this start after altering the pipe?

 

[scorpion1]

Did this start after altering the pipe?

Nope it ran fine just as it sits now and with the stock carb, then one day it just started cutting out and i lost 10 mph. I got this carb cuz the float was bad in the other one and wanted an upgrade.

So, there was NO change to the bike and one day it just started this.

 

[scorpion1]

I may need a vid of it, cuz it may be 4 stroking, not sure...............

 

[Street Ryderz]

I may need a vid of it, cuz it may be 4 stroking, not sure...............

That would be good!It seems like Frankenstein was right and you had an air leak that somehow fixed it's self if nothing was changed.