Newbie here, have a noise ?

[NYboater]

Have a 1990 4.3 175hp with a alpha one, I bought the boat after it had been sitting in storage for 4 yrs, had to put all bellows on the outdrive also with new gimbel bearing. Had to install new fuel pump, starter, and carb rebuild kit. Boat ran great the 1st 3 weeks of use,only issue was a small rattling noise under full load taking off and at wot, if I backed off it would go away. Went out last sunday and the rattling was there but louder and all the time, so I stopped pulled cover off and the dip stick was sticking out 3 inches, I pushed it back down which it goes in hard anyway , you can just about touch it and it pops back out, I crimped it on a little tighter, the loud part of rattle went away but other rattle still there all the time except under 2000 rpm now, choke was stuck open also. Performance of boat seems a little down but not much , temp stays below 150. To me seems like it might be a carb issue , because it dous'nt sound the same as it did the 1st couple weeks. thanks for any help!

 

[Bt Doctur]

Re: Newbie here, have a noise ?

And the outdrive oil is ????????????

 

[NYboater]

Re: Newbie here, have a noise ?

New, changed it when I installed new water pump.

 

[Bondo]

Re: Newbie here, have a noise ?

only issue was a small rattling noise under full load taking off and at wot, if I backed off it would go away.

Ayuh,.... Sounds like a Lean condition causing Detonation maybe...

 

[spect8r]

Re: Newbie here, have a noise ?

Does the dip stick want to pop out only when the engine is running?

 

[NYboater]

Re: Newbie here, have a noise ?

all the time it wants to pop out. I'll have to try higher octane fuel to see if its the problem, it does sound like spark knock. or would there be a different way around this. Timing?

 

[spect8r]

Re: Newbie here, have a noise ?

Timing can definitely be an issue. Easy to check too.

 

[NYboater]

Re: Newbie here, have a noise ?

What should timming be set at? Minimun octane for boat say's 85 leaded or unleaded, I am running 87 with 10% ethanal can not get regular fuel in my area anymore.

 

[Bt Doctur]

Re: Newbie here, have a noise ?

Thunderbolt IV is 8 BTDC
Thunderbolt V is 10 BTDC

 

[ENSIGN]

Re: Newbie here, have a noise ?

Burnt or worn water shutters will give you a clicking noise also.

 

[NYboater]

Re: Newbie here, have a noise ?

What else would cause a lean condition for detonation?

 

[John Evans]

Re: Newbie here, have a noise ?

http://forums.iboats.com/showthread.php?t=209972&highlight=John+Evans

I think I've chased mine down to e-10 and a fuel/water separator/filter problem.
I know it's a different motor but if you can learn anything from my frustration, great.

 

[Kmort]

Re: Newbie here, have a noise ?

And the outdrive oil is ????????????

Just curious. What's does the outdrive oil have to do with this problem?

 

[180shabah]

Re: Newbie here, have a noise ?

Just curious. What's does the outdrive oil have to do with this problem?

I think he was just wondering if it got done after the long list of other things you did - after sitting so long hatge to see you blow a drive....

pinging?

Have you dumped the contents of your water seperator into a glass jar to check for contamination. Water will lean you out real bad, and would account for the "good yesterday, but not today"

Also mentioned above - have you verified the timing yet?

Your 87 octane shoud do just fine...

 

[NYboater]

Re: Newbie here, have a noise ?

I hav'nt checked timming yet, it's been 95 and humid for the last 4days don't feel like messing with it till the weekend, the water seperator is on top of the fuel pump correct?

 

[180shabah]

Re: Newbie here, have a noise ?

it's been 95 and humid for the last 4days

Welcome to my world....gettin' a little tired of the tripple digits this year...


Water seperator LOOKS like an oil filter, nut is plumbed into the fuel system. Should be between the tank and pump.

 

[NYboater]

Re: Newbie here, have a noise ?

Is there another style water seperator? The only thing between my fuel tank and fuel pump ia a small inline filter.

 

[Kmort]

Re: Newbie here, have a noise ?

Hell.... I'm still waiting for an answer to the dip stick being pushed out since I have that issue from time to time along with others

 

[180shabah]

Re: Newbie here, have a noise ?

Is there another style water seperator? The only thing between my fuel tank and fuel pump ia a small inline filter.

You probably don't have one then, now would be a good time to add one. $30 and a couple hours of your time.

 

[adeneo]

Re: Newbie here, have a noise ?

Dipstick beeing pushed out is usually caused by pressure building up in the oil pan. This often happens when there is a ventilation problem and can cause all sorts of trouble if the pressure gets high enough. Usually the dipstick is pushed out before this happens. Check ventilation hoses going from valve covers to flame arrestor, some valve covers also have a screen underneath, where the hose is connected, check to see that this screen (4,3's usually don't have any screens) and the hoses are not clogged.