Back Firing!!

Hi all,

Started the mini up after x-mas today (eventually)
After it splutted into life I found that it was only running on 3 cylinders

I changed the lead which seamed to of cured that but now(another problem), you can't rev the engine because all it does is backfire though the carb!

By this i mean fuel seams to come out onto the bulb head(if air filter is disconnected)

Have reset the carb to factory settings (miles out) have also change the points, plugs, leads, cap, rotor arm, needle and float chamber needle, and the condenser!!!

Its still doing it so i though i better get some advice!!!

Cheers
Dan

I sought some advice from my dad, it could be a stuck inlet valve?

Hope this helps

Alex

Yeah i thought that, and looked into it but that seems OK...

Also used a colour tune tos et the mixture...

This one really does have me puzled!!!

That's a bit of a mystery that one, especially if colortune shows up ok.
Hopefully someone else on the forum might be able to help...

Update:

Have tryed a few more things today still with no effect!!

When it blows back though the carb the timing goes from were it normally stays to 10 degrees, so i assume the vacum advance goes out of action???

I have also tryed running the engine off different fuel and a different pump...

And i am now running out of ideas!!!

sorry I cant offer any advice on this, you've checked everything I would of done.

I'm useless at this engine issues as I've got an SPi, which is the dark side!

robtheplod wrote:I'm useless at this engine issues as I've got an SPi, which is the dark side!

mpi is even darker lol

Just checked about the sticking valve again and it deffently isn't that...

Took rocker cover and plugs and and cranked it over and all seemed fine...

Every thing is set up how it should be and it still won't run???

As soon as you try and move you lose power and it dies and when you restarty it it cranks for ages and then it has no power again due to the back firing!!!

Just been reading elsewhere and it mentions valve clearances can help with this. No idea what I'm talking about, but might help??!!

Come in for 10mins!!!

Absolutly freezing!!!

Really running out of ideas now!!!
Going to take it into work tomorrow and do a compression and a leak test on it!!!

A valve might have burnt out or a guide have taken this oppertunity to give up???

Have you checked the timing?

Studdy snr wrote:Have you checked the timing?

Yep reset all the timing when i did the points...

The weird thing is that when the engine back fires, it throws the timing out by alot but as soon as the engine has calmed down the timing is spot on again!!!

Could be the vacum advance???

??? timing may be 180 deg out ???? thats my worst comment

Are the plug leads in the right order, and the rota arm has not broken the key way we had the same problem last week when racing a nova stock car. or the dizzy drive may be badly worn!

Its on the mend now...

Did the compression test and also the leak!!!

The compressions are
1 - 170
2 - 165
3 - 170
4 - 155

Inlet manifold gasket and carb jet were at fault!!!!!

Dad got the bits from DSN on the way back from work and now its all in pieces abd cleaned up!!!

just put this one down to experance .found it and fixed it