1978 Johnson 140

[drewandamy224]

My johnson still wont run...<br />As per my last post i have gone through the carbs new plugs new fuel lines but under a load and when motor warms up i lose power.and then motor back fires and runs like its out of time.Any ideas Open to anything....

 

[MCM]

Re: 1978 Johnson 140

Hi, as a starting point check to make sure you haven't got your carb adj. set too lean as this would cause backfiring, then go from there.<br /><br />Good luck,<br />Mike

 

[drewandamy224]

Re: 1978 Johnson 140

Originally posted by MCM:<br /> Hi, as a starting point check to make sure you haven't got your carb adj. set too lean as this would cause backfiring, then go from there.<br /><br />Good luck,<br />Mike

 

[drewandamy224]

Re: 1978 Johnson 140

checked and set how they are suposed to be set.

 

[MCM]

Re: 1978 Johnson 140

Hi Drew, I was just reading you other posts, if you haven't made any adjustments to your timing it shouldn,t have changed.<br /><br />When you say you went through the carbs did you rebuild them with a kit? an air leak or vacuum leak could also result in backfiring.<br /><br />Has the motor been overheated in the past?<br /><br />Mike

 

[MCM]

Re: 1978 Johnson 140

Hi, just noticed you live in UT. I live in Roy.<br /><br />Mike

 

[drewandamy224]

Re: 1978 Johnson 140

Hi mike, ya i live in payson. I pulled the carbs broke them all the way down and cleaned them. all the parts looked good and so i put them back.I cant seem to figure this one out. This boat was running good at the first part of summer. could it be the coils? they have alittle movement.I wish i knew more about this motor and boats. Thanks for all your help and anything you can think of holler back.

 

[MCM]

Re: 1978 Johnson 140

Hi, the reason I asked about the kit is that using old gaskets is a no no, found that out the hard way!<br />also parts looking good and being good aren't the same thing. <br /><br />A priority would be to get an oem shop or service manual for your motor, I found a parts catalog is very helpful also.<br /><br />I'm not sure what you mean by your coils having a little movement!<br /><br />Ths web site has alot of usefull info.<br /><br /> http://www.maxrules.com/carbindex.html <br /><br />Mike

 

[MCM]

Re: 1978 Johnson 140

Hi Drew, you may find some answers on the old posts on these links also.<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi <br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi <br /><br />Mike