72 johnson 50 hp wot is very slow

[ccs2595]

The motor sat for about 10 years i took the carbs and fuel lines all apart filter and such cleaned them all up got it running but when i accelerate it just wont get up and go is it still the carbs may be dirty all the jets were good? In idle i can rev it up at the carbs and if sails but under load just won't plane out. Appreciate any help
Thanks
cs

 

[ccs2595]

Re: 72 johnson 50 hp wot is very slow

by the way 155 comp on both cylinders new coils, power pack,plugs
cs

 

[Jacob645]

Re: 72 johnson 50 hp wot is very slow

Try a cylinder drop test.
If you haven't already done so, take your carbs completely apart and invest in a couple of rebuild kits...they're cheap enough for peace of mind. Run compressed air through the jets after letting the carbs soak in some carb cleaner overnight. This should rule out a lot if you do it all correctly. Set your floats properly. Make sure your plugs are gapped correctly...I believe .030? Check your manual...(get a manual )
Next, check to make sure your timer base underneath your flywheel is advancing all the way to the rubber stop. Does it ever just die when you try to give it gas?

 

[larky]

Re: 72 johnson 50 hp wot is very slow

the prop may not be matched to the boat. the pitch maybe too large

 

[tashasdaddy]

Re: 72 johnson 50 hp wot is very slow

did you clean the remove and clean the high speed jets? you have adjustable low speed jets also. http://forums.iboats.com/showthread.php?t=244013
what size boat is it pushing? are you sure the boat is not water logged?

 

[ccs2595]

Re: 72 johnson 50 hp wot is very slow

the high speed jets are the main jets in the bowl right?? i did clean those out and blew air through them.the carbs were pretty nasty inside i will take tham apart and soak them again and do another good cleaning.
it is pushing a 72 imperial tri hull. the floor is actually out right now so i can see that it is not taking on water,
yes it does die sometimes when i take off.
thanks for the help so far i am very aprreciative.
cs

 

[Jacob645]

Re: 72 johnson 50 hp wot is very slow

Sounds like carbs right now, especially if they're dirty. A good idea would also be to decarb using some Sea Foam Deep Creep. I'm sure there is a FAQ about decarbing and there are a ton of guys on here that know how better than me, but I assure you that it does what it says it does. How bout that timer base under the fly wheel? Is it advancing before the throttle arm?

 

[tashasdaddy]

Re: 72 johnson 50 hp wot is very slow

Decarb, take a can of seafoam put 3/4 of it in the gas tank, with only 1 gallon of premixed gas. put the rest in a spray bottle. start the engine, and let it come up to temperature. then remove plugs, and them some real good shot of seafoam into the cylinders, replace plugs, let sit 15 minutes. restart, and spray the rest of the seafoam into the carbs, so the the motor almost stalls, wait and repeat until the seafoam is gone.then take for a wide open spin. then put in new plugs, ad premixed gas to the tank, and take it for a wide open throttle spin. it is going to smoke like a house on fire, during this process.

afterwards compression.recheck

jacob, the timer base would be included in, the link n sinc procedure. which is detailed in the service manual.

 

[Jacob645]

Re: 72 johnson 50 hp wot is very slow

Thanks td for the full meal deal on the Decarbing! I knew someone had the complete process out there. I wasn't sure if he had a manual for the sync and linc. The timing not advancing is another reason why it may die when accelerating, assuming that it is getting gas through the jets.

 

[ccs2595]

Re: 72 johnson 50 hp wot is very slow

thanks fo r the info on decarbing and the help. i take it i can get sea foam at at any marine dealer right?
cs

 

[tashasdaddy]

Re: 72 johnson 50 hp wot is very slow

advance auto parts, and other stores.