johnson 70hp 2 stroke 1995 shut down when warm

gabd

Seaman Apprentice
Joined
Aug 15, 2022
Messages
38
hi everyone ,
im pretty new to the world of boating
i recently bought a little 16foot bowrider with a 70 hp johnson 2 stroke .
im the third owner since purchase brand new in 1995 the is solid and the engine run like a charm.
yesterday i took it for a ride with my friends and as usual the boat start very easily and run very smootly ....
after an hour i was cruising around 4500 to 5000 rpm the engine die by itself .....i was able to restart it very easy .....but after 5-10 minute he die again and he get harder to start. i was wondering if someone had the same issues and the past to help me finding where to start my investigation .
its important to me to do the rapair by myself because i want to learn everything about this engine .
thanks you very much
 

gabd

Seaman Apprentice
Joined
Aug 15, 2022
Messages
38
hi everyone ,
im pretty new to the world of boating
i recently bought a little 16foot bowrider with a 70 hp johnson 2 stroke .
im the third owner since purchase brand new in 1995 the boat is solid and the engine run like a charm.
yesterday i took it for a ride with my friends and as usual the boat start very easily and run very smootly ....
after an hour i was cruising around 4500 to 5000 rpm the engine die by itself .....i was able to restart it very easy .....but after 5-10 minute he die again and he get harder to start.(need to put throttle to the max while starting and put it on the gear very fast to keep it running) i was wondering if someone had the same issues and the past to help me finding where to start my investigation .
its important to me to do the repair by myself because i want to learn everything about this engine .
thank you very much
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,840
hi everyone ,
im pretty new to the world of boating
i recently bought a little 16foot bowrider with a 70 hp johnson 2 stroke .
im the third owner since purchase brand new in 1995 the is solid and the engine run like a charm.
yesterday i took it for a ride with my friends and as usual the boat start very easily and run very smootly ....
after an hour i was cruising around 4500 to 5000 rpm the engine die by itself .....i was able to restart it very easy .....but after 5-10 minute he die again and he get harder to start. i was wondering if someone had the same issues and the past to help me finding where to start my investigation .
its important to me to do the rapair by myself because i want to learn everything about this engine .
thanks you very much
Well if it sat for a long time before you purchased it my guess it's fuel related. (Tank, hoses, carbs....) But it can be lots of things. Most on here will want model number, compression test numbers, spark test, etc. Then they will comment.
 

gabd

Seaman Apprentice
Joined
Aug 15, 2022
Messages
38
hi there .
thanks for helping me out
i do have tested spark and everything is fine
havnt check compression yet and i will provide the model number when im back home tonight
 

tphoyt

Lieutenant Commander
Joined
Jun 10, 2010
Messages
1,555
Agreed with above. Has the water pump been serviced since you bought it.
That’s always the first step to a new to you motor if it’s age is unknown.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,781
Oil injection in service ? ----Tested ?----Bypassed and mixing oil and gas at 50:1 in the tank?----Or no idea.-----Overheat horn tested ?
 

gabd

Seaman Apprentice
Joined
Aug 15, 2022
Messages
38
the engine is oil injected
i dont know when was the last service of the water pump but i noticed she was working
the engine havnt over heated
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,781
Post compression test numbers.----Install a new water pump impeller.-----Test run with another tank and hose.
 

gabd

Seaman Apprentice
Joined
Aug 15, 2022
Messages
38
Post compression test numbers.----Install a new water pump impeller.-----Test run with another tank and hose.


okay i will
do you have any suggestion for a good place to order parts ?
im in canada
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,781
Where in Canada ?------evinrudeparts.ca-----Along with this site here.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,781
evinrudeparts.ca ----can offer free shipping on orders of $79 or more.-----You need to do some trouble shooting / testing before ordering parts I say.---I suggest the latest water pump kit with instructions.
 

gabd

Seaman Apprentice
Joined
Aug 15, 2022
Messages
38
i bring the boat to my friends garage tomorow i will get the compression of the 3 cylindre and investigate more in this direction .....i will double chek fuel filter, line and pump .....do you know any way to test the water pump ???
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,781
Impeller should be replaced about every 5 years.----But test your overheat horn.
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,840
i bring the boat to my friends garage tomorow i will get the compression of the 3 cylindre and investigate more in this direction .....i will double chek fuel filter, line and pump .....do you know any way to test the water pump ???
Well there is the pee stream. That says the pump is pumping. But that doesn't say if it's flowing around the engine. (Thermostat failure or passage ways plugged.) If you have a thermal gun (fairly cheap) you can shoot the heads when warm. Looking for 130 or so. Still think it's the fuel system but all the other things still need to be tested. Hope this helps.
 

gabd

Seaman Apprentice
Joined
Aug 15, 2022
Messages
38
its defenitly helping me a lot
and when you said fuel system you mean tank , line . filter and pump
right ??
 

gabd

Seaman Apprentice
Joined
Aug 15, 2022
Messages
38
im 100% sure the pee stream was on but i will check thermostat
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,840
thank you so muchim near vancouver in british columbia
And by the way, because I'm not aware of your boating knowledge, you did make sure you have oil in the reservoir? Because if your alarm is malfunctioning and no oil......
(No disrespect intended) Also, you can just check for spark you have to check for GOOD spark. That means a tester that measures how far the spark jumps. Again, if you didn't do anything reckless, and those tests check out....old dirty or water contaminated fuel or the vro needs help.
 
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