1970 johnson 6hp seahorse

[FLAlien]

I recently bought a johnson 6hp an I got the carb rebuilt and got it home running it in a tank and it won't reach high speed I double checked the carb I pulled the plugs one bye one and it stayed running it runs and idles great but I can't get it to rev up like it should could this maybe be the fuel pump

 

[racerone]

Re: 1970 johnson 6hp seahorse

Step # 1 is a compression test.---------------Will spark jump a gap of 1/4" or better on both cylinders ?---And does the primer bulb on hose go hard ?------Could be a ruptured diaphragm too.

 

[Bosunsmate]

Re: 1970 johnson 6hp seahorse

check the timing arm advances to the full advance stop, ie its not getting stuck somewhere

 

[FLAlien]

Re: 1970 johnson 6hp seahorse

We'll I figured by the way it's running compression should be a problem cause it sounds great just can get up to speed I checked the spark everything's looking correct and what do you mean by something getting stuck are you talking about the throttle arm if so it's going it's full way to give gas I even push it with my finger and no difference it's all the way open I'm just try to to take the fly wheel off cause I'm thinking it might be the fuel pump cause I bought like a 84 6hp johnson and put it on cuz it seemed the same little square fuel pump coil it not match up maybe I try blowing and sucking through the fuel like going into the carb from the fuel pump I can't blow in it but I can suck but should it be able to suck since it's sucking gas into the carb bowl

 

[FLAlien]

Re: 1970 johnson 6hp seahorse

I'm sorry it was the timing arm advancer where would that me located

 

[Bosunsmate]

Re: 1970 johnson 6hp seahorse

have you tried pumping the primer bulb?
the advance on that should spin the plate thats under the flywheel

 

[FLAlien]

Fuel pump ???

Fuel pump ???

I have a 1970 6hp johnson seahorse runs great for hours just idleing but when I give it gas it hardly accelerates I tryed pumping the bulb while it was running the bulb stays hard I can't pump it at all but if I disconnect the fuel line right before it's out of gas it revs up an goes like no tomorrow but once I reconnect it it just slows down and maintains it's slow speed again I check spark it's all there both cylinders I'm stumped

 

[FLAlien]

Re: 1970 johnson 6hp seahorse

Yes I pumped the bulb while it was running no difference it's hard can't pump it and yes the advancer is going all the way and pushing the gas opened

 

[racerone]

Re: Fuel pump ???

Re: Fuel pump ???

Has the high speed jet that threads into the carburetor bowl been removed / inspected / cleaned.-----Not just I think it is clean.

 

[racerone]

Re: 1970 johnson 6hp seahorse

High speed jet may still be plugged !

 

[FLAlien]

Re: Fuel pump ???

Re: Fuel pump ???

Yes I took the motor to the shop and had them rebuild it I too it to them not running they rebuilt the carb and now it's running great but can't seemed to accelerate I took the carb apart my self after the shop and made sure it was clean so everything new on the carb everything's sparking as should idk where else to look I'm pretty new to these little outboards

 

[FLAlien]

Re: 1970 johnson 6hp seahorse

Had it compelely rebuilt all new and I rebuilt it my self just to make sure cuz that's the first thing I read about was the high speed jet for my problem but no change

 

[racerone]

Re: 1970 johnson 6hp seahorse

You say there is good spark.----Good compression.-----------Clean carburetor.------Motor should run properly !

 

[Bosunsmate]

Re: 1970 johnson 6hp seahorse

Really would be useful to get compression numbers like racerone said

 

[FLAlien]

Re: 1970 johnson 6hp seahorse

Could the motor still run good even if compressions bad cause I'm saying the motor seems to run like a top just the accel

 

[racerone]

Re: 1970 johnson 6hp seahorse

Simple testing will quickly get you the results you are looking for.--------I own more that one of these 6 HP motors.-They are elegantly easy to inspect / rebuild / repair.------Last 2 I bought were $75 each.

 

[FLAlien]

Re: 1970 johnson 6hp seahorse

I was just seeing cause at the moment I don't have a compression tester and idk of any other ways to check if there is any but wat if there is bad compression is there anything to do for that or that need a hole rebuild huh

 

[racerone]

Re: 1970 johnson 6hp seahorse

Could be a blown head gasket between cylinders.-----Gives you even compression on the 2 cylinders but it will be low.---------Seen that more than once over 40 + years of repair work.-------Testing is the path forward !

 

[FLAlien]

Re: 1970 johnson 6hp seahorse

Ok thank as soon as I can Imma got buy a compression checker but idk if I said when I pull the gas line right before it runs out of gas it runs like no tomorrow then one I hook gas back up it just slows back down

 

[Bosunsmate]

Re: 1970 johnson 6hp seahorse

pulling the gas line will make it run leaner. Any adjustment screws on that carb?