97 johnson 130,dies when punched from idle.

[Kevin E]

I have a 97 Johnson 130 hp V4 with 80 hrs on it.<br />It seems to idle too low,600 rpm,and dies at idle<br />periodically. To punch it,I must take the throttle off idle,1000 rpm,or else it will die when throttle is increased quickly.If the throttle is increased moderately it accelerates fine. At speed the engine runs fine.When the engine is run out of the water with hose water cooling it idles very high,1200+,and rough. The problem is worse at higher elevations. I found a vacuum hose that was disconnected and reconnected it,this helped but not much. the vacuum hoses appear to be in good condition. I have fresh fuel and good quality oil in it.

 

[12Footer]

Re: 97 johnson 130,dies when punched from idle.

So far, your aproach has been dead-on. To go the next troubleshooting phase, you need to run a compression test. Poorer performance on the water than on muffs is an indication of poor compression, or a plugged exaust port.<br />Not being under a load, an engine missing one cylinder will run a slightly lower RPM, but other than that, would run normally,until it is put in gear.It will then become very apparent.<br />Where you find low compression (which cylinder),will also help you to know.<br />When you have the plugs out for the compression test, note thier condition and color, and which cylinder it serviced.<br />If the compression is good, you may have a blocked or restricted exaust,due to carbon.So try a shock decarb treatment, and re-test the compression. If it improves, you may have fixed it, by opening up the exaust, or un-sticking a stuck ring.<br />Decarb and new plugs every 80hours on this engine under normal operating conditions,more frequently, if you live in a idle-zone manatee infested waterway <br />So anyway, if the compression is ballpark to begin with, look for one cylinder doing nothing (wet and clean, or dry and tarry).

 

[Kevin E]

Re: 97 johnson 130,dies when punched from idle.

Thanks for the advise. I'borrowing a compression gauge so I wont be able to do that till wed. I did the shock decarbon and my idle on muffs went way up from 1300 to 2000, I wont be able to put it on water till next week to see what that translates to under water. The plugs all looked the same,dark brown not too crusty,a little oily around the threads. I bought new plugs and will install after the compression ck. Thanks again,<br /> Kevin.