tanaka tc-47 not staying tuned

locksmith

Member
Local time
10:54 AM
Joined
Apr 2, 2013
Messages
62
Location
TX
Hey y'all i got a question about tuning my carb... My old carb was bad (used motor) and i replaced it with a brand new one! it started right up and ran great! i did very minimal adjusting (low screw 1/8 turns) to the right cause it was dying from too much fuel

It went from about 70 to 50 degrees (texas lol) and the engine is starting, then getting bogged down when I pull the throttle. like it goes for a second then bogs... sometimes it dies


when it's been off for 10 minutes, i have to put it in choke again when it should start in run.. if it bogs when i first pull the throttle do i tighten the low screw? or do i need to adjust the high? once it's running it's great, but off the line at low RPM's it dies

please tell me how to tune it

thank you
 
unless youre completely lost and have to start over again...

back off counter-clockwise, to richen the bottom end slightly.

basically, when warm, set idle a bit high, then adjust lo speed until engine peaks, back off 1/8th. reset idle. blip throttle, if it bogs, back off another 1/8 or so..
 
thank you, yesterday i tightened the lo screw and it runs better!

i feel it was too open and was being flooded with fuel. it seems better with the idle faster
 
i still can't get the lo screw in the right place! When i start it up, the low screw is too tight and the motor stalls. Then I open it up a bit and it's fine.

But after 30 min of riding, it starts to stall at low RPM's when i pull the throttle. So it has to be tightened again.. it's so strange

what am i doing wrong?
 
doing the exact reverse to what i said, and ignoring the fact that the LO speed only controls the low throttle settings, and really, you should be tweaking the HI needle at the same time as thats the needle that does the most work...


tightening LEANS IT OUT.

leaning it out causes it to die.

loosening the screws richen the mix.

this makes it burble, smoke, drip wet goop from the exhaust and never quite rev out fully, but it will run, and always run...

wheres my wall?

 
Actually, you're wrong. Loosening it makes the engine stall and die... I air on the side of loose for the engine sake, but it does have to be tightened after riding. It runs better when tighter after riding for a while

I am really tired of this engine. I have a 40cc on my bike that I may put here instead. I live in TX where the weather changes all the time, so I carry a screw driver with me, but the constant adjustments are super annoying

The engine is fast as hell, but it is also very temperamental to tune and it's getting on my nerves. I will never buy another hi/lo tunable carb
 
and how did you replace the carb? dry or with plenty of sealant? if you used sealant...oops. bad idea.


my experience with any walbro/tama (or other diaphgram manufacturers) carb is to simply strip them completely, and get the compressed air on to them, in every hole, port and orifice. check rubbers for holes, then retune, set both needles at 2.5 turns out, get the hi end right, then fiddle til the lo is right. all of half an hour, not catering for removing shrouds, cables, covers, and other grrr bits that belong in the bin :giggle: resorted to a rebuild kit once and never used it.

one speck of dirt, or sealant in the wrong places...

but everything points to either you not being familiar with the operation and tuning of these carbs, or something is wrong with the carb itself, despite being new. unfortunately, im inclined to suspect some degree of operator error...


what do tree loppers and lawn maintenance people do around there? same type of carbs on their engines, doubt most have ever touched them with a tool other than to change blades...
 
-It is a walbro hda 97 carb. It's big

-I didn't use sealant, I just bolted it on. The carb was brand new and sealed, so I'm confident it's intact and functional. I am sure I'm doing something wrong... At first I wasn't giving it enough time to start up... Each 2 stroke motor I've had (I've had lots) is a little different for starting. This one, I've found it's better to let it idle at half choke for 20 sec before putting it in run. But today, it died after idling for 20 sec in run...

Then I loosened the Lo screw 1/8 and it was worse, so I tightened it back 2/8 (1/8 ahead of where it was). Then when I got to school, It was bogging from being too tight, so I loosened it up and it ran well, where the scooter is strong off the line. I am no genius at these, but I can tell that the motor is inconsistent in where the screws should be.

There is about a 1/2 turn 'zone' where the motor runs well for the lo screw. It seems to want a different position in this 'zone' every day. my 40 NEVER has these problems and runs a lot better. I will talk to some lawn guys. thanks.

-thank you, I will check out the muffler
 
Back
Top