intrepidvoyager
Petty Officer 1st Class
- Joined
- Mar 24, 2009
- Messages
- 216
Ramblings about carb cleaning incase anyone is interested..... slow day here on old Kauai ..
Anyway I always keep a can of carb cleaner on board to help out guys who's trolling motors won't idle ....
I read thru the locked post on carb cleaning instructions and surprisingly, to me, found nothing about using pressurized cans of carb cleaner ........ I used to do it the old way ..soaking etc but since the advent of pressurized cleaner with the little red tube I wouldn't do it any other way ...the big advantage of pressurized cleaner is you can actually see the flow thru the carb circuits which obviously you can't with compressed air. ....... also you can often clear the idle circuits with the carbs in place with excellent results .....
Re: '78 model 700 not idling right ..... ( that was the original post )
OH ....thought you had them off once already .....OK ....try this ...take the float bowels off if you can .....maybe tricky without detaching the carbs and do as much of this as you can .. (if you can't get the float bowels off easily try last para below) ... while you are doing this tilt the engine slightly forward so as not to totally flood the engine.
...fuel delivery and air delivery ..got to be close to 14 to one or won't work .. the idle fuel port is a tiny hole in the venturi ... it is fed by a tube going into the float bowl ...so squirt LOTS OF carb cleaner in the idle fuel tube and make sure it comes out in the venturi. there may be two or 3 tubes ..just find the right one .... you got to make sure idle fuel is getting to the venturi ......NOW screw out the idle mixture screw half way and repeat the process ......carb cleaner should come out both the fuel port and the AIR supply somewhere ....if not put your finger on the venturi fuel port and squirt more carb cleaner into fuel tube ... if no carb cleaner comes out somewhere the idle air delivery is blocked ....once its clear put your finger on the fuel port and squirt LOTS OF cleaner both ways . its not only dirt you are looking for .... old fuel glaze ..really bad if you use gas with ethenol in it. some carbs have a removable mixer jet .... if you can't get it out just repeat the cleaning process a few times. By now you should be soaked in carb cleaner ...if not you have not used enough .. .... now if your idle screws have o rings replace them ...sometimes i find they are missing ..... coat the o ring with vasoline when you instal so the o ring does not get hung up on the hole ...good luck. I have not gone into mid range or high speed jet ( emulsion/mixer ) as that is not your problem.
assemble using new float bowel gaskets ( don't use sealer ) and seat the idle screws and back them off 2 turns ............ let the engine sit overnight and then try starting .... it won't start right away as there is no fuel in the float bowels. ....if it runs fine then drop the bowels and use sealer unless you got o ring profile rubber gaskets which don't need sealer.
If you get some improvement you'll know you are on the right track !!
PS ...if you can't get the float bowels off open the drain screws pull the idle screws and using the little red tube poked thru a rubber washer squirt carb cleaner in the hole ...the idea is to hold the washer against the opening surround with a long 6 or 8mm socket so most of the carb cleaner goes in and does not spray back at you ..... This worked once on a friends boat that had to leave asap and i only had half an hour ...good luck !!!
Long and short ......the engine now idles fine .
Anyway I always keep a can of carb cleaner on board to help out guys who's trolling motors won't idle ....
I read thru the locked post on carb cleaning instructions and surprisingly, to me, found nothing about using pressurized cans of carb cleaner ........ I used to do it the old way ..soaking etc but since the advent of pressurized cleaner with the little red tube I wouldn't do it any other way ...the big advantage of pressurized cleaner is you can actually see the flow thru the carb circuits which obviously you can't with compressed air. ....... also you can often clear the idle circuits with the carbs in place with excellent results .....
Re: '78 model 700 not idling right ..... ( that was the original post )
OH ....thought you had them off once already .....OK ....try this ...take the float bowels off if you can .....maybe tricky without detaching the carbs and do as much of this as you can .. (if you can't get the float bowels off easily try last para below) ... while you are doing this tilt the engine slightly forward so as not to totally flood the engine.
...fuel delivery and air delivery ..got to be close to 14 to one or won't work .. the idle fuel port is a tiny hole in the venturi ... it is fed by a tube going into the float bowl ...so squirt LOTS OF carb cleaner in the idle fuel tube and make sure it comes out in the venturi. there may be two or 3 tubes ..just find the right one .... you got to make sure idle fuel is getting to the venturi ......NOW screw out the idle mixture screw half way and repeat the process ......carb cleaner should come out both the fuel port and the AIR supply somewhere ....if not put your finger on the venturi fuel port and squirt more carb cleaner into fuel tube ... if no carb cleaner comes out somewhere the idle air delivery is blocked ....once its clear put your finger on the fuel port and squirt LOTS OF cleaner both ways . its not only dirt you are looking for .... old fuel glaze ..really bad if you use gas with ethenol in it. some carbs have a removable mixer jet .... if you can't get it out just repeat the cleaning process a few times. By now you should be soaked in carb cleaner ...if not you have not used enough .. .... now if your idle screws have o rings replace them ...sometimes i find they are missing ..... coat the o ring with vasoline when you instal so the o ring does not get hung up on the hole ...good luck. I have not gone into mid range or high speed jet ( emulsion/mixer ) as that is not your problem.
assemble using new float bowel gaskets ( don't use sealer ) and seat the idle screws and back them off 2 turns ............ let the engine sit overnight and then try starting .... it won't start right away as there is no fuel in the float bowels. ....if it runs fine then drop the bowels and use sealer unless you got o ring profile rubber gaskets which don't need sealer.
If you get some improvement you'll know you are on the right track !!
PS ...if you can't get the float bowels off open the drain screws pull the idle screws and using the little red tube poked thru a rubber washer squirt carb cleaner in the hole ...the idea is to hold the washer against the opening surround with a long 6 or 8mm socket so most of the carb cleaner goes in and does not spray back at you ..... This worked once on a friends boat that had to leave asap and i only had half an hour ...good luck !!!
Long and short ......the engine now idles fine .