Logo
FULL SITE MENU

1968 18hp fastwin runing on one cilnder

V

vortex864

New member
Hi i'v been working on this thing for some time now. it runs on the top cilender only but somtimes the bottom one will work wen i gun it a few times but now always. i got spark no both plugs and i'v replased every thing. i rebilt the carb twise and got new fule pump, wiers, plugs, new gas lines, points, coils, condosers, and looked at the fan looking vales behind the carb. there's nuthing wrong with them. the little ring that the pints plate skrows to has a crack in it but i dont think it's that it still solid and there's no play in it. I'm stumped. I dont think it's a gas thing but dont know if it's a fire thing. Thanks for any thoughts on the matter..
 
Are the coils properly adjusted ?-----Are the plug wires fully seated in the new coils ?-----Are the points perfectly clean ?----Any oil / dirt on points means they will not do their job.-----------Compression test may show a blown head gasket.
 
i got spark no both plugs
Click to expand...
It needs to be a loud and snapping blue spark to ignite the fuel/air mix.
i rebilt the carb twise
Click to expand...
If the engine sat for a long time the gas in the carb idle circuits can dry out leaving rock hard varnish deposits. Soak the carb bowl again for 24 hours then blow it out w/100 PSI compressed air. I will use acetone or lacquer thinner in a closed can left outdoors because the vapors can kill you in a confined space.
 
thanks but i'v done all of that and some.. My dad think the exhaust my be clogged in one port not letting gas get to one piston. I got good spark and relay good compression. 98-100 in both. the exhaust is about the only thing i'v not done yet.. doses this sound like it could be it? I don't think it's the head but I haven't donr that yet too.. thanks..
 
You may have a loose Upper main bearing too.
Check those points again. Change the gap to see if that changes the condition.
When you pull the Bottom Plug wire does it make the engine idle rougher?
 
Back
Top