gday all, My cousin has an a12 in his off roader and he was saying how it was gutless at low rpm and really needed its tits revved off to go anywhere.

Any ideas on what i could look at to try to fix it when i go up there on wednesday?

I was planning to look at the primary venturi on the carb, then the ignition timing static then to see how it advances as well.

anyone else got ideas on what could be causing the lack of low end? I know that the a12 wasnt a torque monster but it should go reasonably well which it sounds like it isnt. he said you are almost f**ked if you dont have revs up when coming out of a hollow.

Definitely check dizzy, leads, points, idle jets by the sounds of it. A can of carby cleaner is also your friend!

off roader? what sort & how much does it weigh?

i was just going to take up a different carby and wack that on and try it. Ill check the condition of the ignition system as well as timing it up.

if it aint carby or a spark then its probalby not worth fixing as it would be engine rebuild and swapping engines is easier.

heres a picture of it:

sounds like a normal a12 to me ;)

Yes, the stock A12 has best power at 3000 to 5000 rpm.

Someone probably put a large duration cam in it. That'll make it gutless at low RPMs.

The best place to start is with a full standard tuneup. You know, check the plugs, points, timing & have a listen to the tappets. If they are a bit quiet, then run the feeler gauge through them too.

Spray some of the good stuff through the carb & if it has a bad flat spot, then swap the plug leads on cylinders 2 & 3 then start it up. A few nasty backfires should dislodge any rubbish in the main jets, but do it with the air cleaner in place for best results & greatest safety.

If the carb is the problem & the backfires clear it, then drop the two brass plugs from the bottom of the fuel bowl & with any luck the dislodged particle will be washed out when the bowl drains as these plugs are at the base of a well at the bottom of the bowl.

Make sure that you refit the plug leads correctly & that all the drained fuel has dried.

Oops, just noticed, it's a non standard carb.

I've found that closed up points make them not want to worth a damn down low.

had a look at it. interestingly it wouldnt idle with that carby on it so we put a hitachi 306 carby onto it off an a12 engine and tried that, bugger all improvement unfortunately. Found that the engine has a H89 head on it which wouldnt help with low end.

Engine runs nicely with the hitachi carb on it but still no get up and go and im now thinking that the beast is just too heavy for the poor little engine!

Free-revving the engine will go up and beyond 9000rpm!! I done know what work has been done to it internally.

That thing shouldn't weigh too much.