89 johnson 70 hp vro dies randomly

[Yakfsher@yahoo.com]

I have a 17th aluminum bass boat with a 70 hp johnson. When it's running it runs great. But it will randomly die on me. It can be at idle or full throttle. And it doesn't sputter or struggle before it dies it just shuts down. And then sometimes it can take a little bit to get it started again. Sometimes when on plane if it dies, if I pull the throttle back to neutral quick enough it will stay running. I have replaced fuel filter and made sure carbs were clean. Not really thinking it's a fuel problem though. Replaced the plugs as well. It's as if I turned the key off.

 

[jakedaawg]

Okay, where to start...

I'll start with a question or two.

When you say carbs are clean did you spray carb cleaner through the throat while engine was running or did you take them apart and thuroughly clean every passage and jet?

When it quits and you go to restart do you need to squeeze the primer bulb to get it to start and if so does it need a lot of squeezing?

Does the motor "sneeze" right when it dies?

Do you have a manual?

Does the problem occur after a similar amount of time? For example, when it dies while at idle does it die at idle repeatedly after say 20 minutes but dies in 5 minutes under higher load? I guess I am asking if it only seems to happen once the motor is warmed up.

Regardless of any of the questions above a spark test is in order. This should be performed with an open air gap spark tester set at 7/16". Do it while cold and then do it again immediately following a failure. Results need to be repoted back.

A fuel sample into a clear jar would be helpful. You want nice clear fuel, with no phase seperation.

 

[South Paw]

How did you "make sure the carbs were clean"?

 

[emdsapmgr]

Could be a couple of problems: Possible spark problem. Next time the engine just "shuts off" do a test. Crank the engine and check all 3 spark plug leads for spark. You can use a spark-gap tester for this test. If you've got strong, blue spark, then it's likely a fuel issue, which could include a fuel restriction or even a weak fuel pump. You can test for this problem by constantly priming the fuel hose bulb. This will force extra fuel into the carbs. If the engine runs just fine as long as you constantly prime the fuel hose bulb-it's a fuel issue.

 

[Yakfsher@yahoo.com]

Carbs were taken apart and cleaned. I can't say there is any pattern to when it dies. Sometimes I can go 20 minutes or more continuous run with no issue. Other times it will die 5 times within a few minutes. I did take a fuel sample and it did have a little water. I treated the fuel with dry gas. I installed a clear fuel filter so I could see fuel as it runs. When the motor dies there is still fuel in the filter. The filter only runs about quarter full but someone told me that might be normal for some boats. I don't have a manual.

 

[Yakfsher@yahoo.com]

As for pumping the ball, the motor dies to quickly for me to get to the ball. But I have pumped it after it dies to see if it restarts better. Does not seem to help. Sometimes it takes 30 seconds or more to restart. Sometimes it starts right awaay

 

[jakedaawg]

The water in the fuel is certainly an issue. Get another tank and run on that. Dry gas isn't really an answer.

 

[Yakfsher@yahoo.com]

Wouldn't water in the gas cause it to sputter and run rough if it was enough to cause issues?

 

[jakedaawg]

Wouldn't water in the gas cause it to sputter and run rough if it was enough to cause issues?

sometimes, but enough could shut it down. Either way it needs to be ruled out, dont forget to drain the fuel line and the carb bowls.

The spark test immediatly following issue will tell something also.

 

[Yakfsher@yahoo.com]

Ok I know it's been a while. I still can't find the issue. Boat is at the shop but the guy is having trouble figuring it out also. Spark is good. Compression is 110 110 and 114. New bulb put in. Tank sucked out dry and water separater installed. Still having random kill issues. Ran probably an hour straight after we drained fuel tank and put water separater in. Then sputtered once at full throttle and recovered. 5 min later motor shut down at full throttle. Restarted and died as soon as I pushed the throttle down. Did this twice then would not start for 10 minutes. A couple times I got a continuous buzzer sound after it died and I tried to restart but not all the time. Water stream is cool and strong? Could the vro be on its way out??

 

[flyingscott]

Check all the wires in the stator and cdi units make sure you have no breaks or rubbing wires.