So here is the latest problem with my 81 Brat. The car starts great and idles most of the time. After driving it for a while (lately around 10 minutes) it will start not idling at all so the car dies at stop signs and any time you engage the clutch and let off the gas. However, the car starts right up after this. The problem has gotten progressively worse over the last few months. Now it is getting to the point where it very rarely idles after running for a bit. Any ideas on what is causing this? This forum has kept the Brat on the road the last few years, I really appreciate the help.

Have you played with the carb? I think its time for a Weber.

 

Also check the disty timing and look for vacuum leaks.

 

-Bill

Im going to vote simple first. When was the last time you changed your fuel filters? Plugs, wires, rotor, cap?

Good call with the simple fix. The dist. cap and rotor were pretty marred up. It ran good today after replacing them, hopefully it will keep it up. Thanks for the help guys.

If they were really marred up you might want to check your distributor shaft for lots of side to side play. Hows the timing when you put a light on it? Does it jump around a bit?

So the problem went away for a day and now it is back. The cap and rotor still look good. It idles fine for about the first five minutes and then it wont idle at all. I replaced spark plugs and wires today but it didnt change anything. I dont have a light but I will try and get a hold of one to check it.

Had similar problem just a little while ago in my 79 brat. Rebuilt the carb and that fixed that! Now she just purrs. And I think it may actually pass emissions too.

 

Had trouble finding the rebuild kit at first. But they actually had it at Kragen.

I put a timing light on it today and the light was consistent but every second or so it would miss. I have never messed with a timing light before so Im not sure if it is suppose to be a consistent cadence or if that missing is a sign that something is up. When the light was consistent it was hitting at around 12.

Hate to be redundant. Mine was missing to till I rebuilt the carb. The plugs were also showing that it was running very lean.

yeah sorry i guess I have been in denial about carb thing. They kind of scare me.

Heck its easy, well within the scope of an amateur mechanic. The kits even come with instructions. One thing that the kts don't tell you is that some of the gsaket surfaces warp, especially the ones by the fiber spacer. Sometimes they need to be resurfaced, but this is easy and can be accomplished with a nice long file.

 

Trust me. Your problem sounds soo identical to what I just went through. And I wound up troubleshooting and inspecting everything else before I addressed the carb. And now its a whole new machine. Its never run better.

Alright looks like I can get a hold of a kit, is there anything else in the carb I should replace while I am at it that isnt part of a standard kit?

Nothing I can think of, but lets see what the other members have to say. Might be a good opportunity to replace vacuum hoses and what not, but I can't think of anything in the carb you'd need that's not going to be in the kit.

My '78 Brat is doing the same thing and the carb was replaced a year ago.

I too can report a similar experience with poor idle and a bad miss at constant speed in my 81 brat.

 

Just last week, replaced carb with weber i had rebuilt and boy what a difference! My problems did not entirely go away however and this lead me to discover the Dizzy was completely worn out (lots of side to side movement). i have now installed a rebuilt dizzy (as well as cap and rotor) and can not believe how much performance has improved in all ways.

 

Install of carb not a big deal if you take your time.