Help , no high speed ...

[Alabama Chuck]

Looking for help solving a high speed problem.
Once we get above 3500 RPM the motor sputters and dies .
New high pressure pump.
Also $600 spent on Mechanic , but he could not even fix ???
Motor is a T60TLR 2006 4 stroke..
Help ..
Alabama Chuck in Lillian

 

[99yam40]

what all did he do for that $600

 

[Alabama Chuck]

Well Pete is a trained Yamaha mech.
Redid the water pump ,went over the high pressure pump and checked out the motor for a hour in the tank.
After that I brought it home and it would not run 5 min

Took it back. He worked on it more. He even tested it on the water. Same problem.
4 to 5 k rpm it shuts down.

So I replaced the high pressure pump again , new filter on the pump and thought I solved it.

We can Cruze @2500 for hours , but once you take her up to around 4 K she acts up.???
I am a good mechanic ,but this motor is kicking my butt.
Also it has very ,very low hours for a 2006.

I'm thinking a float problem ,or pressure regulator ??

Any expert help would be very much appreciated.

 

[robert graham]

Sounds like a fuel flow problem for sure….is your fuel tank vent open and working?

 

[Alabama Chuck]

Well Pete my mech even hooked his personal tank to test run it. Same problem , different tank .
?????
He also tested pressure as he has the equipment
to do so.

So far here are parts I have installed.
New fuel lines , bulb , water separator, filters , lift pump , high speed pump & filter last week
..
I suspect a float that's not set right in the high pressure unit ????

 

[99yam40]

sounds like VST is not staying full so it runs out at higher RPM because it uses more fuel at higher RPM.
what do the pressures do when the problem shows up

 

[Alabama Chuck]

Dont know , what pressure does. Dont have a gauge but might just get one.
Just paid for a pdf download manual and will che cm float levels..
If all else fails going Suzuki.....

 

[99yam40]

float setting will not help if the lift pump can not keep the VST filled.
monitoring the lift pump pressure and rail pressure will tell you something about what is going on when the problem shows up.

if the tech ran it on the water, surely he monitored pressures to see what was going on

 

[Alabama Chuck]

Thanks guys for all the ideas.
Will get a pressure gauge to monitor.
Then go from there
Till tomorrow another day.
Alabama Chuck

 

[Alabama Chuck]

Hello from south Alabama on Perdido Bay.
So many tasks to do today.
But the first one was to putts around the T60TLR pontoon motor.
So first I removed the Belt protector just to observe the fuel hose routing .
1. pumped up bulb hard.
2 followed house to water separator bowl. ok
3. follow hose to lift pump and checked flows there, good full flow.
4 connect lift pump back up and remove outlet side hose , pumped fuel thru the pump and had a good flow...
5. one more part till the VST and that was an inline strainer.
SO what the hell I should test flow coming out of the strainer....
It was NOT good !!! seemed to be restricted to "half" pressure....
I must have reversed it when I took it off and accidentally cleared the
blockage. So I reinstalled it after a thorough exam and retested it.
A lot better flow..now
Happy with the flow I will test later today in the Bay and have ordered a new one..

I can see now that the strainer flow was sufficient enough to to cruse at
a low speed , but not enough to supply the higher volume of fuel needed the 4 to 5K rpm's from the motor..

Will report again after the test tonight , way to hot to do in the day...

Alabama Chuck

 

[Alabama Chuck]

Hello from South LA.
Lower Alabama..
Life down here is getting hot and the alligators have moved into the Bay..
A 12 ft gator has been cruising the shores just north of the 98 bridge.
Hip Hip Hip Hurray mates
Thanks for all the input with my high speed problem.
Like I said before I traced it down to the inline filter right after the lift pump
The Micro screen let just enough gas to cruise but not get any speed above 3500 RPM.
So I ordered a Genuine Yamaha Filter 6C5-24251-00 filter strainer.
that took over 6 days and then we had Tropical storm Claudette blow
right over the bay.
SO this afternoon we got a window to test the new part .
We took the pontoon out on Bayou Grande just north of the Navy Base.
There was a mile long no wake zone and then I slowly opened her up with a prayer.
3000 rpm , 3500 , 3800 , 4000, 4500 , 4900 & finally 5100 rpm ..
I let her cruise a full 3 miles and no problem to speak about .
Tested her for another 2 hours and was so happy..
Thanks to all who chimed in with support.
Over & out
Alabama Chuck







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