Well still having issues getting my brat moving. Rebuilt the carb for the most part (was my first carb rebuild). Wish I could get rid of the craptachi and get a weber but have very limited money. The problem is I have a severe backfire (intake) when accelerating. Pretty much any load on the engine and it happens. When trying to drive it, the car bucks and rocks like crazy and almost stalls out. I am thinking my accelerator pump is whack but not sure if that would be the only issue.

It definitely run a lot better since being cleaned however now the idle sits around 1250 and the idle screw is all the way in, and as I write this I realize the idle screw didn't make any difference in the idle. But to be honest for now I don't care about that, I can live with that for now even though it's a sign something is not right. I just need to be able to drive it for the rain season, but can't even get fast enough to get out of second gear...

Any pointers would be great, I'm just getting stuck and irritated and can't seem to find any solutions from anywhere

 

Thanks

-Brian

Sounds like the timing is off or it's extremely lean - maybe a bit of both.

 

GD

I've double and triple checked the timing...however that was at 1300 rpms. Where i had it timed at 9* so it should be more back to 8 around idle where it should be. The lean sounds right but I'm out of ideas on how to actually fix that.

Tomorrow I plan on adding a small spacer to have the accelerator pump be pushed a little further to see if it's not even doing anything. When I do step on the gas, it barely move the little orange plunger on top...

I had a hell of a time with a similar problem not long ago. It turns out that the flywheel I replaced had completely different timing marks on it.

 

You didn't happen to change yours too? Find TDC and see if the marks correspond.

I actually did just replace the flywheel/clutch a couple days ago (which works great compared to the chewed up old one with shot PP and squeky throwout bearing). However this was a problem before and still after that. And I just double checked and it is still correct.

Okie dokie.

 

Timing is correct. Idles at 1250rpm. What is the throttle screw up to? and how does the float level look.

 

I'm not sure why it won't idle any lower than 1250 but it has little to do with the accelerator pump. All the pump does is give a little extra squirt when you floor it. the rest of the fuel comes from the main jets and the power valve.

 

The misfire sounds to me like an ignition fault. If the timing is correct then you might check the condition of the points and points gap, the dizzy cap for cracks, the condenser and the coil.

Just had a thought that maybe I tightened my cable back down on the tight side so maybe it doesn't close all the way. Will check tomorrow...

 

Not sure which throttle screw you're talking about, but I had the fast idle screw back all the was off and idle was still high...

 

It's not a misfire, just an all around intake backfire when under a big load. I can slowly rev it 4 grand no problems with no misfire. And I recently (within the last 2 weeks) replaced the cap, rotor, wires, and plugs, and checked the coil to be in specs.

sorry. I meant fast idle screw.

I still think it is a timing issue. My guess is you are still too retarded. I would think that at 1250 rpm the timing might want to be as much as 20 degrees BTDC. Is the engine getting over warm?

Fortunately I do not have any over heating issues. I'll try advancing it a little bit more when I get off work and see if it improves at all...

Jumping in late here, but does your vacuum advance work? Most early Brats have a hole in the vacuum advance diaphragm and won't advance the timing properly once you're off idle.

THE BRAT LIVES!!! :banana:

 

Thanks for all the help everybody finally got it all running right and now I hear the exhaust backfires that I thought I should've in the first place since it's all rusted out...

 

The solution...double check your timing!

Went back to double check and look at TDC on #1 then looked at the rotor position...and it was pointed exactly the opposite way...so realigned the wires to the according position and voila! Ran like a champ with no intake backfire!

 

Figures karma would bite me in the butt because I thought the one thing I did right was the timing :-\

 

Again thanks for the help everyone, just questioning the work I did made my error visible!

Good on ya mate!

 

Happy days.