[fishinrookie]

im not sure whats wrong not to good at repairing boat motors .but it starts right up runs good for about 5 to 10 seconds then it starts backfiring it sounds like its popping real bad i pulled the plugs and they seem to be pretty wet and they are black in color. it seems to smoke alot when i do get the r.p.m up im putting 3 oz of oil to a gallon of gas is that right or am i putting to much
thanks for any imfo you can give me

[tashasdaddy]

is it back firing like a gun, or cough or sneezing?

[F_R]

1972 what size? 3oz/gallon is correct when mixing small qty. One pint to 6 gallons when doing a tankful

[fishinrookie]

Originally Posted by tashasdaddy

is it back firing like a gun, or cough or sneezing?

its 25 HP its more like coughing but then again it sounds like a gun going off in water its getting good spark it starts right up runs good for very little time then starts COUGHING
PLEASE HELP ME i dont even know were to start to figure out the problem
its got a new fuel pump on it and the filter is clean of dirt
thank you for helping a rookie out

[tashasdaddy]

try the 1st section of this, http://forums.iboats.com/showthread.php?t=167352

[fishinrookie]

why cant i find any adjustment screws on the carberator i look every were on that thing and cant find not one .how are you going to adjust it if there aint no screws

[F_R]

Originally Posted by fishinrookie

why cant i find any adjustment screws on the carberator i look every were on that thing and cant find not one .how are you going to adjust it if there aint no screws

What do you mean there ain't no screw? Somebody steal it? Don't you have a knob on the front of the motor, next to the choke knob? Isn't that knob linked to a needle valve in the top of the carburetor? That is the slow speed mixture screw.

[fishinrookie]

ok now i feel dumb i know alot about how a 2 cycles run but as you can see i know nothing about boat motors.yes i see what you are talking about i will give it a try after work today i realy hope i can get this dam thing to run right god knows i dont want to get stranded out on the lake again

THANKS FOR THE HELP

[fishinrookie]

well i reset the carb. and it still has a bad hicup not sure were to go now
im puzzled. should i rebuild the carb? any one have a suggestion

[bgdavid]

Check for air leaks in the fuel system and it woudn't hurt to pull the fly wheel an check the points. Had this problem with a 72 25hp that I'm restoring and once I replaced all the hoses, fuel screen gasket, points and synchronized the linkage it runs like a champ. Old fuel will cause this also.

[clearwatguy]

im a newbie too but on my 72 125 horse the choke linkage was stuck closed once and made it act like you are describing