timming 5.7 260

[lappa]

revisiting an old issue
last season had trouble timming mercrusier 5.7 260 IV thunderbolt igniton
problem: can not get below 12 degrees should be at 8

when get below 12 it will not idle.
what should i try befor spending 350 -400 in new IV thunderbolt
what is exact timming procedure for thunder bolt 4?
at present time if i push engine past 3200 3500 it starts to ping it seems to be advancing to much
hope you can help
thanks

 

[Haut Medoc]

Re: timming 5.7 260

Welcome to iboats....
I would ask if you are sure the plug wires are in there correct position....
Though you did not mention the year, the timing procedure should be no more than loosening the dist hold down nut & turning it till you get the desired setting & tightening again........
Yes, pinging is most likely from being too far advanced....
Not good!
​

 

[Haut Medoc]

Re: timming 5.7 260

Have you done a full tune up?
A vacuum test might shed some light as well.....​

 

[Don S]

Re: timming 5.7 260

On the Thunderbolt IV ignition, it's just aim the timing light and move the distributor.
The the engine is dying because of low rpm, just adjust the rpm up some then bring the timing down.
Do you have a link to that old thread so we don't have to ask all the same questions AGAIN?

 

[lappa]

Re: timming 5.7 260

year is 1990
have done all the above
full tune up
plug wures checked if may have jumped tooth on distributer
is there a way to check the igniton block IV thunder bolt
carb also rebult
it runs graet at 3000 rpm also at 1000rpm
i dont know where to start this year