91 yamaha 150 v6

[stihl99]

Just bought a 91 proline equiped with a 91 yamaha 150.First run last weekend went great.No problems.This weekend the problems started.I guess its just typical with used boats for me.
Anyhow,carbs all got stuck in the wide open and wouldnt close.Fixed that but dont know what caused it.When giving it full throtle it comes up and then instantly looses all power as if it was starving for fuel.I had my GF pump the bulb and every squeeze it would regain a bit of throtle and power but no enough to sustain plain.
The primer bulb is not hard like it should be.Do they go BAD??This started sat afternoon.We took it back out sunday.NOTE:I did change water/fuel seperator.could problem posibly be the fuel pumps?It idels fine,just no real power,wont go over 10mph.Or could it be the primer bulb.
If it sounds like the fuel pump then i will rebuild them and change the primer bulb just because.There only a few bucks.

Next problem.
Im running it in the yard to flush it and notice while its running theres hardly any water comming out of the water port located near the power head.It was a fast trickle.Most motors ive seen being flushed have a steady stream.I then noticed a single red blinking lcd bar above the temp gauge.There yamaha gauges.Does this motor have a impeller or is it a water pump?Hard to do?I have always worked on all my own veicles..from motor changes to auto glass.

and last and hope it all ends here.
My trim unit is not working.It sounds as if it is low on fluid.What kind of fluids do I use and where would the filler hole be located?Any tricks to doing it?

Thanks for reading my ramble.Im very frustrated after spending the money on a boat that I cant use.Its just seem like murphy law was over my shoulder all day.

CHECK THIS OUT..the day ended by me snapping off the rear roller on my trailer while pulling my boat....lol.Should I hang up boating or what????????damn what a day

[Hamfisted]

Check your email.


Mike

[Ken]

stihl99,
Welcome to BOAT OWNERSHIP !!!
And even the new ones require maintenance.
First - get yourself a Yamaha shop manual - you can purchase one online at www.yamahapubs.com - it will pay for itself many times over.

First problem - stuck float valves or weak fuel pump. I would do a carb overhaul - teardown, clean, and install a kit. If that fuel pump is more than five years old, replace it.

Second problem - the side discharge, aka pilot stream, pee-stream, is just an indication the water pump is pumping - but really does not tell you how well - you really need a pressure gauge for that. The pilot hole gets clogged up right at the point where the hose attaches to the nipple that snaps into the lower cowling. Take the hose off and tape it to the lower cowling so that it points downward and run the motor with the earmuffs. Clean out the nipple connection.
If the water pump (the impeller is just part of the water pump) is more than three years old, do a water pump repair (kit).

Third problem - the filler hole for the t/t unit is mounted to the side of the housing. You need to get the motor up to get to it. Loosen the bypass valve that is located on the side of the motor bracket - there should be a small round hole on the side of the bracket - look in there and you will see the head of a slotted screw. Turn the screw ccw (cw on some models) until it stops. Manually pick up the motor (may take two persons (don't use your "GF" on this one) and drop down the locking lever. (Re-tighten the bypass valve). Now you should be able to see the t/t unit and the filler cap. Fill to the bottom of the neck of the filler hole with t/t fluid (dexron 2/3 ATF).

Boats.net, sponsor of this forum, is a great source for parts - check 'em out.

And don't worry about Murphy's Law - it's universal when it comes to BOAT OWNERSHIP [img]smile.gif[/img] !!!
Good luck,
Ken K

[stihl99]

Ken,
Mike emailede me the manual for a 93 which looks the same as the 91.
This gona sound retarded but here it goes.When the boat is on the trailer or sitting in the water at idle it shows 1/4 tank of fuel.I changed the bulb yesterday and took it out for a run.It came up up for about 3 minutes and then dropped right back down starving for fuel.I then noticed the fuel gauge blinking low on fuel.Sound like a float problem or what?I no longer have overheating issue.I think i solved that one.I was able to blow air down into the water discharge at the PH.I could then clearly hear air bleeding out from the LU.When I had it out there yesterday It had a nice heavy stream of water comming out.The carbs were redone a year ago.The tank from what the owner said is a 70 gallon...does tyhat sound about right for a 19` proline???If it does I would bet I have maybe 10 gallons of fuel in it now,which makes it real easy to suck up all the common crap into the pickup screen.Im gona try filling it ($3.06)and running it again.

the trim unit ended up having 2 bad seals which let water in to it.I have a mechanic working on it now.Hes gona replace and flush unit.
Check this one out...FIRST thing he noticed was my stearing arm.He looked at it and said thats not far from breaking and gave me the run down on what it takes to replace it.Told me how the 6 bolts that hold the PH to the LU like to seize.Im not happy about that.I talked to the old owner and he said the PH was off less then 18 months ago some im hopping it comes of easily for me.This job will be done by me.

Ill keep you guys updated on what I find.
Thank you very much for the replies guys...preciate it.

ken ...amen on the murphy`s law lol


Mike thank you for the manual

boat...bring on another thousand.
in my case Bring On Another Two

[jb123]

if you change the arm and pull LU and PH, be sure to use a HIGH quality never seize to ensure you will never wrestle those bolts out again.and while youre at it, check to see if the shift shaft has been replaced yet as the old ones were non stainless.

[stihl99]

thanks for that pointer...I was told that as well today.He said the later models...think 93 up had stainless but the older ones like mine are just hardened steel.I wonder if that could be replaced with a stainless one...any one know?

[Ken]

stihl99,
Take a look at your motor in the online catalog (above for boats.net). Your original shift shaft will probably be shown as "replaced by number ***". It should be stainless.
If you order from boats.net, they can tell you if the new one is stainless.
Good luck [img]smile.gif[/img] ,
Ken K

[jb123]

as far as i know there are no more non-stainless sold/made.

[Andy Hope]

water on flushers
i have never been able to provide enough water through the muffles to run my angine for long and make it come out of the tell tale her over heat alrm normally comes on
but never had any problem in the water
but nover a bad thing to get the impellor changed
andy

[stihl99]

i pulled carbs off and blew out the main jets.1-1/4 turns on all jets.None of the gaskets ripped and all seem to be in good shape.Is it ok to reuse them??
I pulled my fuel pumps off and the top fuel pump had a rip in the diaphram located inbetween the body and the rear plate cover.Does this sound like my fuel problem?I have a rebuild kit on order from boats.net.

[Hamfisted]

Jason make sure you do both fuel pumps. You can reuse the carb bowl gaskets, but I would use new base gaskets, you don't want a vacuum leak there. If the power head has been off before you shouldn't have any problem getting it off again. The previous owner probably already had to change the shift shaft out. That's why the powerhead would've come off. Of course use all new gaskets when you put it back on. Inspect the upper motor mounts while you have it off. Maybe even put a HydroTec 5252 tuner on it while you have it apart [img]smile.gif[/img] . All the new replacement parts have been upgraded to stainless.

Andy make sure you're using flush muffs that feed both sides of the water inlet. The type that has the "Y-pipe" feed, not the cheap single side feed. Yamaha V6 motors like a lot of water volume. Its common to get overheats on those cheap single side feed muffs.


Mike

[stihl99]

thanks Mike...I did order kits for both fuel pumps.steering shaft has already been replaced by a mechanic.All I took off was the carbs and cleaned em up.I will be putting them back on with new intake gaskets.The bowl gaskets are gona be replaced because the carbs all sitting off the motor right now and they only take about 15 mins to do...as long as I dont have to take the floats apart to do so =[.If so I will leave the gaskets cause they are in good shape.

whats a hdrotech 5252??

[stihl99]

Issue solved.Was indeed the fuel pump.Just a little pointer for anyone diagnosing a fuel issue.If the primer bulb does not get hard you most likely have a fuel pump issue.Befor I changed the fuel pumps the primer bulb would not get hard...after,it get hard.All is good and my boat fired right up.Happy times