Droping rpm Johnson fatstrike 175 -92

[Daniel Beckman]

Did put my boat in the lake for the first time this year.<br />The engin started up perfect,put it in about 3000 rpm out of the harbour. Put it on WOT. The first ten second the engin run perfect and hit 5500 rpm but then suden it drop to 3000.<br />Still with WOT i notice that the engin did try to hit higher rpm running up and down.<br />Did set the engin on idle and again WOT run perfect again for abou ten sec. and then drop back to about 3000 and keep doing like that???<br />Any idea?

 

[Bass Runner]

Re: Droping rpm Johnson fatstrike 175 -92

Be careful it might be a high speed jet has some trash in it, if so you can trash a cyl, or could be coils laying down or just a simple case of plugs giving up at high rpm. When it did this did you check the plugs to see if they are wet, dry?

 

[Daniel Beckman]

Re: Droping rpm Johnson fatstrike 175 -92

Thanks. Didnt check the plugs, will try again tomorrow and check the plugs.

 

[Daniel Beckman]

Re: Droping rpm Johnson fatstrike 175 -92

Didnt run the engin today but checked the plugs.<br />They all look the same not to wet and not to dry, normal i guess?

 

[Daniel Beckman]

Re: Droping rpm Johnson fatstrike 175 -92

Did a try again today.<br />The engin runs fine up to 4500 rpm.<br />Did run for about 5 min at 4500 rpm, the engin runs perfect, then i slowly raise the rpm and at 4800 the engin start to stutter like it get to little gas.<br />Got an alarm that tells if the engin get to little gas but the alarm dosent sound (maybe the problem could be after the alarm sensor, dont know where it checks if it got enough gas).<br /><br />Did check the plugs right after it start to stutter, just turned the engin of and release the plugs (they all did look the same, dry)<br />anyone?<br /><br />Also one more thing. At the front of the engin there is an little air nipple at the gaspump, whats that for?

 

[Daniel Beckman]

Re: Droping rpm Johnson fatstrike 175 -92

Thank you all for the reply's!<br /><br />Now i finaly found the fault thanks to all the replys i got on here.<br /><br />I have posted a several message about this problem and now when i finaly solved it i think its in the place to tell you all and hope it can help someone else with the same prob.<br /><br />In the top post here i said the engine drops power after about ten sec at 5500 that was not really true it did drop rpm when it hit around 4800 rpm.<br />The fault was the shift switch, dont not really know why but about 4800 rpm the little knob on the switch was pressed in a litte like it should do when you put the engine in or out of gear.<br />Did put the shift switch out of its holder so it had no chance to put that knob.<br />Now the engine runs perfect (knock on wood) so now i will erase just a littel of the knob so i can get it work like it should again (without it it can be just a little tricky to get the engine out of gear)<br /><br />Once again thank you all.<br /><br />Ps. <br />Here you can find some pics and a short video to show you what im talking about.<br /><br /> http://www.carlskoga.com/boat/shiftswitch/