125 force backfirein and what lower unit

[johnzanardi01]

hi people well i have a 1258f8c force 1988 witch has been rebuilt when it was fired up it is backfireing out of the exh on in and it seems to be number 3 pot when it dose it it stops the engine i couldnt tell u if it was doing it before it was rebuilt due to i brought it in a million bits
compresion is 150 psi even on all 4 and new plug i also need to know what lower unit can i run the power head is 1258f8c but the orignal leg was 25" and i got given a 20" mid section of 906x91a what one can i use buy the way motor had hose in the inlet port in the midsectionn and was ran for 60 second max

 

[eurolarva]

Re: 125 force backfirein and what lower unit

Usually a backfire is a timing issue. Could be the wrong wire is attached to the wrong spark plug or the flywheel key is broken.

 

[john from md]

Re: 125 force backfirein and what lower unit

It can be switched plug wires or switched CDI wires causing this. Since it was just rebuilt, the chances of someone switching wires is quite probable. Open up the manual and trace the wires on your engine so that they match the appropriate schmatic.

John