1999 Yamaha 200 TLRX Surging Issue

[Bstahl]

I have a 1999 Yamaha V200 TLRX that has been having a surging/fuel delivery issue. Just got this boat from my dad, but it's something he's had issues with for some time now. It happens when coming off plane, or when not WOT (3000-5000 RPM’s). When surging there is a vicious shake through the remote and hot foot. Motor occasionally shuts down when at its worst, but can usually drive through it by giving it more throttle.

Have tested fuel pressure to check for possible collapsing fuel lines and tested the fuel pump. No loss of pressure when surging happens. Swapped out the CDI as well as the O2 sensor (last shop that looked through everything suggested it may be one of those two items).

Motor runs great at WOT, but when I start to slow down or come off plane (3000-5000 RPMS's), the shake begins.

Had a buddy tell me he had a very similar problem with an old Mariner and it ended up being the throttle position indicator. I've looked through schematics and wasn't able to find what part that would be.

Thoughts?

[yam911]

I am not seeing a 200TLRX model at the Yamaha website. Which if it exists would have carburetors.

Your mention of an O2 sensor leads me to believe the motor might be a V200TLRX. Is this correct?

[Smallie_Hawgin]

I have a 1999 Yamaha 200 TLRX that has been having a surging/fuel delivery issue. Just got this boat from my dad, but it's something he's had issues with for some time now. It happens when coming off plane, or when not WOT (3000-5000 RPM’s). When surging there is a vicious shake through the remote and hot foot. Motor occasionally shuts down when at its worst, but can usually drive through it by giving it more throttle.

Have tested fuel pressure to check for possible collapsing fuel lines and tested the fuel pump. No loss of pressure when surging happens. Swapped out the CDI as well as the O2 sensor (last shop that looked through everything suggested it may be one of those two items).

Motor runs great at WOT, but when I start to slow down or come off plane (3000-5000 RPMS's), the shake begins.

Had a buddy tell me he had a very similar problem with an old Mariner and it ended up being the throttle position indicator. I've looked through schematics and wasn't able to find what part that would be.

Thoughts?

Had similar issues, exact same motor (P200TLRX). I had a cracked/rusted reed valve block. Did custom reeds and went through the carbs (carb kits), fuel pumps, inline filters, bulb and did the link and sync sequence to verify timing and fuel delivery. Certainly helped with all of my motor issues. Certainly sounds like a fuel delivery issue. The TPS would likely cause issues throughout the RPM range though... If your motor is indeed the same model and not the fuel injected variety, there is no O2 sensor, just temperature switches and sensors. Two stroke motors are simple... Right? :) Just Air, fuel, compression and spark... LOL

[Cphil]

Not sure if you’re carbed or not but don’t over look simple things like carb float height. Someone must have been in my carbs before I bought my boat and the floats were all out of whack causing the bowl to not fill enough and major fuel starvation.

[yam911]

Somewhat difficult to help trouble shoot a motor issue when the model of the motor is not known.

[Bstahl]

Yes, sorry. It is the V200TLRX

[Bstahl]

Bump

[marinetechnician]

Don't know if it will help but you should do a complete sync and link if there have been people messing with it. This is usaully an over looked item. Need to be sure everything is adjusted correctly. Just curious but was someone watching fuel pressure gauges the whole time ?