Zeda stage 2 issues

[mangosmoothie]

Hello all,

I've got a stage 2 zeda (shark head, zeda reed, window piston, ported by zeda), HP carb (the cheap ebay one with a pod filter), mz65 pipe, NGK B6HS plug, and gasbike cdi. I've taken the reed apart and used Mazda RTV gasket maker where the reed bolts to itself. I've tried the stock cdi and plug as well.

I still can not get this thing to run right. I tried the 70 jet that came in the carb. It would bog at anything past half throttle until it was running, then it would sluggishly rev all the way after it was very hot. But idled crazy high, and would hang really badly when I pulled the clutch in. A 75 jet was better. Now I have an 80 jet in it and it's the best it's been. Pulls the hardest it ever has (still slow though), idles the best it has, still has a little bit of rev hang when I clutch in after a pull, but that's the best it's been. But it seems like a dog compared to my $100 ebay kit with the stock pipe and nt carb I have on another bike.

Keep jetting it richer? 80 seems stupid rich for these little engines. I've never heard of one needing a jet this high. It isn't smoking out the pipe and isn't 4 stroking as far as I can tell. I still need to check the float height. Is 21 mm accurate for HP carbs as well? I ordered some larger jets to try. Anything else I should check on this thing?

I have not tried running this stage 2 with the NT carb which I suppose I could try.

And lastly, is there a cylinder head torque spec for the cnc aluminum? I'm out of ideas or things to check.

 

[6blueoval9]

Youre using the hp carb aka dellorto clone carb with the motor?

If the head studs are fine thread its likely in the 40ish ft lb range..if its the course threads its in the 60ish range...im getting these numbers from CRMachine but for exact numbers they are on his site.

To me the bogging and high idle etc you describe means lean..if its improving with bigger jets then keep going with it although id recommend a much bigger carb if its that dellorto clone..reed valve motors tend to like more of an oversized carb..i would try zedas oko 21mm carb..

That hp carb is sort of good for a stock to mildly modded non reed motor...you have reeds and porting and higher compression and a good pipe etc..in my opinion a bad choice of carb...the motor will want more air and fuel than that.

 

[Street Ryderz]

Hello all,

I've got a stage 2 zeda (shark head, zeda reed, window piston, ported by zeda), HP carb (the cheap ebay one with a pod filter), mz65 pipe, NGK B6HS plug, and gasbike cdi. I've taken the reed apart and used Mazda RTV gasket maker where the reed bolts to itself. I've tried the stock cdi and plug as well.

I still can not get this thing to run right. I tried the 70 jet that came in the carb. It would bog at anything past half throttle until it was running, then it would sluggishly rev all the way after it was very hot. But idled crazy high, and would hang really badly when I pulled the clutch in. A 75 jet was better. Now I have an 80 jet in it and it's the best it's been. Pulls the hardest it ever has (still slow though), idles the best it has, still has a little bit of rev hang when I clutch in after a pull, but that's the best it's been. But it seems like a dog compared to my $100 ebay kit with the stock pipe and nt carb I have on another bike.

Keep jetting it richer? 80 seems stupid rich for these little engines. I've never heard of one needing a jet this high. It isn't smoking out the pipe and isn't 4 stroking as far as I can tell. I still need to check the float height. Is 21 mm accurate for HP carbs as well? I ordered some larger jets to try. Anything else I should check on this thing?

I have not tried running this stage 2 with the NT carb which I suppose I could try.

And lastly, is there a cylinder head torque spec for the cnc aluminum? I'm out of ideas or things to check.

An #80 jet is good for a small carb in the 14-17mm range but as the poster above said with that engine and a reed you should be using a 21mm or bigger carb and a seperate pilot jet main jet style carb to be able to dail it in propperly the main jet will probably be in the high 90's.

 

[crassius]

usually, head torque depends entirely on the amount the head studs will take - for 8mm studs that is 10 to 12 ft/lb (tho 15 is used by some if needed)

lot of guys lately with sprockets too small to get well into the power band (had customer 3 days ago & I'm at 150 pounds, but could not get his 36T sprocket above about 4500 RPM)

 

[mangosmoothie]

I'm pretty new to this hobby, good info so far. The carb I have looks like this

I also thought it felt lean due to the bog and idle hang, and it backfired on the 70 jet. Only using this carb because it because it came on the stage 2 motor and Zeda said he never needed to jet a stage 2 motor. so I assumed something was wrong with my setup somewhere.

I have a 19mm phbg (which has the pilot/main set up) on the way. Ordered it a few days ago. I'll have main jets #65 70 75 78 80 82 85 88 90 92 95 98 by the time it gets here so hopefully that helps me get closer. Wish I posted this earlier though and got the 21mm I also have an IR thermometer on the way to check head and exhaust temps, so that may also help.

Thanks for the suggestions guys.

 

[mangosmoothie]

usually, head torque depends entirely on the amount the head studs will take - for 8mm studs that is 10 to 12 ft/lb (tho 15 is used by some if needed)

lot of guys lately with sprockets too small to get well into the power band (had customer 3 days ago & I'm at 150 pounds, but could not get his 36T sprocket above about 4500 RPM)

Yes, this stage 2 kit has a 36t sprocket on it. My cheapo ebay bike has a 44t. So I have 40t and 44t on the way. Hopefully that helps it along as well. St Louis isn't exactly flat.

 

[6blueoval9]

And lean miss fires

The 19mm should help but id still go bigger...21mm is pretty much even considered "small" in reed valve engines..

usually, head torque depends entirely on the amount the head studs will take - for 8mm studs that is 10 to 12 ft/lb (tho 15 is used by some if needed)

lot of guys lately with sprockets too small to get well into the power band (had customer 3 days ago & I'm at 150 pounds, but could not get his 36T sprocket above about 4500 RPM)

Are those specs for the cheap chinese head studs?...im asking because i have to now assume crmachine must use a chrome moly type head stud for his torque spec numbers.

 

[Street Ryderz]

And lean miss fires

The 19mm should help but id still go bigger...21mm is pretty much even considered "small" in reed valve engines..


Are those specs for the cheap chinese head studs?...im asking because i have to now assume crmachine must use a chrome moly type head studs for his torque spec numbers.

Freds torque specs are in inch pounds!

 

[6blueoval9]

Freds torque specs are in inch pounds!

Oh...nevermind then

Well ok then..12 inch lbs equals 1ft lb so dont snap off your head studs..lol

 

[mangosmoothie]

70 ft lbs is what I torque the axle on my motorcycle to so I figured that was in lbs

Hopefully this has some balls to it soon.

I'm not looking for huge top speeds, just something that rips til about 35. My commute to school and around town is 25 mph roads with stop signs and stop lights everywhere.

Oh, and I need to be faster than my dad's Honda metropolitan. Lololol