Yamaha 150hpdi 2006

Mick.Roe · 01 September 2021, 20:20

Hi, I’ve recently got a 2006 Yamaha 150 hdpi 2 stroke outboard but I’ve found that when I open the throttle either in gear or using the idle leaver the revs increase but when I go back to neutral or lower the lever the engine does not decrease the revs only turning off the key then restarting the engine brings them back down. Any help would be appreciated

Jon Tallis · 02 September 2021, 08:21

Mick,
Firstly congrats on getting the HPDI, they're an absolute weapon of an engine when running right but fiendishly complicated and hard to diagnose when not. There are also very very few people left in the UK who truly understand how they work!
Have you got YDS?
Have you got the manuals? If not, PM me and I'll send them to you.
Back to your problem.....have you checked all the obvious stuff first like sticking Morse cables, throttle linkages, butterflies. Is your TPS working correctly (you'll need YDS to check this). Sticking linkages would cause your problem but wouldn't explain why it resets on key-off. Dodgy TPS might though.....
PM me if you want to discuss - I know the HPDI fairly well

Mick.Roe · 02 September 2021, 15:53

Hi Jon, thank you for your advice, it’s much appreciated. I’ve taken it into our local outboard mechanic, who as you suspected also think the issue is with the TPS so he’s ordered one for me.
I don’t have the manual so if it isn’t too much trouble would you be able to forward them to me ?

Jon Tallis · 02 September 2021, 17:14

Sure Mick -PM me your email and I'll send you the manuals
Make sure your mechanic (or you) have got YDS software and leads - you can't set up the TPS without it unless you make up a special test-harness.
Worth going though the whole throttle sync settings at the same time to make sure it's all 100% right. All in the manuals.