Mac 10-10 / Walbro SDC carb help

Mike mandry · Oct 3, 2003

I just put a carb kit in the walbro SDC carb on my 10-10

darn thing is running rich as heck. I imaging the needle is leaking ??

I have done dozens of carbs & never really had any problems up untill this one.

I bought some kits from manufacturers supply. This one did not have a new needle, just the diaphrams & gaskets.

The old needle looked perfectly good. However, I did replace it with another (new) one that I had laying around out of a tillotson kit. The one I replaced it with was exactly the same as the old one (I checked it very carefully & measured it with my calipers)EXCEPT that the tip had a "Pointier" tip on it. The old one had a blunt tip. the OD of the new needle was exactly the same as the old one & the length was the same as well

Do you think this is causing the problem ??

It started right up, but would only run at about half throttle. Adjusting the low side had no effect whatsoever (well, not much)

It would run with it almost seated.

I drained the fuel & fired it back up to run it all out. As I suspected, it ran great as it started to lean out when it was running out of fuel.

Any ideas/suggestions greatly appreciated.

Old needle is on the left, new one on the right.
The picture is crappy, but the old needle has more of a blunt, or flat tip, where the one I put in has a sharp tip.

I put a kit in my homie Xl-102 that also has an SDC & it had the same blunt tip needle as well.

Mike

Mike mandry · Oct 4, 2003

Well, I pulled the carb apart & put the old needle back in it. Will have to wait till the morning to fire it up.

Don't think the neighbors would like me doing it @ 1 AM

rupedoggy · Oct 4, 2003

Looks like the slot where the lever fork rides is longer on one than the other. This would allow more fuel into the carb on the short one. BTW could you do us all a favor and clip unnecessary extra junk out of your pictures? They would load a heck of a lot faster. Mike

eyolf · Oct 4, 2003

FWIW, I formerly sang MFG supply's praises, because they gave excellent service. I was impressed with the fact that I could order over the net on Friday and have the stuff on Tuesday.

I have noticed that nothing I've gotten from them is a name brand product, and in some cases that's OK. But in some cases it isn't. For example, I ordered 3 carb kits for the small Briggs slurp and suck carb on my push-mower...I put all 3 in (one at a time) and it still refused to run well. I paid mega-bucks for one uptown and all's well...

I called them about a kit for the Walbro carb on my old string trimmer...they have one kit for the whole series, no guarantees if it will work or not for any individual carb, no idea who packages it. I decided to pass.

JimL · Oct 4, 2003

At work I only use kits made by zama-walbro-tillotson-teiki- ect, the only ones i dont is the TK kits..

Mike mandry · Oct 4, 2003

OK, I got it. Put the old needle in & now it is OK, took a while to get it adjusted, but it runs & cuts good.

The slot where the lever fits had the same dimension (I measured it) Only diff. was the tip ??

Now, can someone tell me why I can't hear & feel my hands ??

Jeez, does that thing vibrate, its a lot worse than my homie SXL

Thanks for all the input guys.

Mike