carb problems 30 hpjohnson

[zmississippi]

my motor only runs good if I cup my hand over the carburetor .Any ideas what could be yhe problem? I rebuilt the fuel pump and replaced fuel lines.Also i"m not sure if i have the lines from the electric pump in the right place. As it is now i have a line running from choke pump to the top of the carburetor. Not sure about the nipple on bottom of intake and top of engine and whether a hose shoulld tie in with the choke or should it just go top to bottom.thanks

 

[wildmaninal]

Re: carb problems 30 hpjohnson

What is the year and model number of the motor?

If the lines are correct, (which I can't tell right off without knowing the year of the motor), then you might just need a good carb cleaning. As somebody else has said here on Iboats a manual is a man's best friends.

Welcome to Iboats by the way. These guys are great and are willing to help.

 

[zmississippi]

Re: carb problems 30 hpjohnson

thanks,I'm not sure,I think it's either 89 or 79. Are they similiar for a number of years in this range?

 

[HighTrim]

Re: carb problems 30 hpjohnson

What is your model number?

 

[wildmaninal]

Re: carb problems 30 hpjohnson

thanks,I'm not sure,I think it's either 89 or 79. Are they similiar for a number of years in this range?

To answer that question, no. 10 years with different models, there can be allot of differences.

With the model number these guys will be able to tell exactly what motor you have.

 

[zmississippi]

Re: carb problems 30 hpjohnson

thanks for the replies,I don't have the model number,The tag is missing and the freeze plug has been re-painted over with no impressions of a stamped number.Sorry I didn't reply sooner.My son was using computer.

 

[tashasdaddy]

Re: carb problems 30 hpjohnson

it doesn't matter what year, putting you hand over the carb increase the fuel/air mix. you have either a dirty carb, bad fuel pump, or air leak. it is starving for fuel.

 

[HighTrim]

Re: carb problems 30 hpjohnson

Does pumping the primer bulb help? If so, may look to the fuel pump. If it hasnt been rebuilt and bathed in a while, i would start there.

Get a vacuum gauge and hook it inline on the fuel hose before the engine, along with a clear section of hose. Take it for a spin, noting the readings and monitor the fuel flow through the clear hose.

Findings:

-Vacuum of less than 2 inches and air bubbles in the clear hose indicates an airleak into the fuel system
-No air bubbles and less than 2 inches indicates a bad fuel pump
-Vacuum over 4 inches indicates a restriction.

Sample gauge

"http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&sspagename=STRK%3AMEBTOX%3AIT&viewitem=&item=4610113711&_trksid=p3984.cTODAY.m238.lVI"

 

[wbeaton]

Re: carb problems 30 hpjohnson

it doesn't matter what year, putting you hand over the carb increase the fuel/air mix. you have either a dirty carb, bad fuel pump, or air leak. it is starving for fuel.

That sounds like the answer to me. They didn't make a 30 hp in 1979. They came about 1984. Either way, it would be pretty much the same as the Johnson/Evinrude 20-35 hp motors of that era (late 70's to 90's).