Yamaha fx svho 2015 limping mode

[Fx jet]

Hi guys,
I need some help. I have a yamaha fx cruiser svho 2015, it has 250hours on the clock, service done 25 h ago, clutch 40h ago. Mostly stock, rive intaje, intake grate, solas prop. It was running with no problem before with these changes.
After riding for 20-30 min the rpm drop to around 5000.if you let it cool down back to 7500 max. No alarms are coming up. The reduced rpm come gradually down, 7000 to 6500 them 6000 until 4500-5000. I checked the clutch immediately after runing and it turn only in one direction. Ideling all normal. Starting all normal. If i acellerate it tries to go but as soon it goes over 5000 it does back and reacts sluggish. This is now happening since the last 5h running.
Please Could you give me some ideas what to check?

 

[tdonoughue]

I don't think you have a limp mode problem. Limp mode is where the computer limits the rpms in order to protect something (overheat, etc.). Were it limp mode, you would be at 7500 and then 'bang' suddenly at 4000 rpm (or whatever speed). Gradual coming down in rpm makes me think you have an engine issue (rather than a computer issue). Is there a fuel filter? Maybe it is getting clogged? Or bad gas? Temp sensor (not adjusting the mix as the engine heats up)?

Doesn't sound like clutch (the rpms would stay the same and the speed would go down). Nor plugs (then rpms would just never get up there). Nor impeller (the sluggishness would not go away when you cooled down).

So those are my initial bets: fuel filter, gas, temp sensor.

Hope that helps some.