timing question and trouble shooting help

[michaelrj9]

Hi all,
I have 1985 bayliner 2750 ciera sunbridge with omc chevy 350 motor upgraded horse power(upgraded horse power to 280 Ithink.I was told that by who I bought the boat from)

changed out the heads for rebuilt ones (even thou these heads were new )beause we were having rocker studs pulling out,nuts backing off, then found out 1 boss was cracked.


After we put the new set of heads on got everything put back together,set the timing to what the man had the boat before me had marked on (don't know if it was correct (but would of thought it was as it was marked)


We took it out for a few minutes did not have good power trying to get it to plain then we heard lots of noise from the engine again.(not sure if it is the rocker arms coming loose again or something else.We were too discusted hearing noises again.So we will know more tomorrow if it is the arms comming loose again on the new set of heads or sometyhing else.

we were thinking it might of been the timing way off making it fire way too soon or too late.because after we got it back to the dock the noise was almost completley gone even reving it in nutral.So maybe it was just under a load.

If it is the rocker arms comming loose what could be causing this.It supposed to be a rebuilt motor.


I need to know if anyone knows what the correct timming should be? what degree? what rpm etc..also If anyone knows what the points should be at.
The book I have is for a 1986.Would the 1986 settings in the book be the same?



any other ideas on what to check with this thing
Thanks for all your help

Michael

 

[michaelrj9]

Re: timing question and trouble shooting help

Can a mechanical fuel pump make a clicking-tapping sound?
It sounds like the noise is comming from the fuel pump.
At higher rpm's seems like only in gear which is confusing
Anyone know if this is possible?

Thanks

 

[searay3]

Re: timing question and trouble shooting help

If your going to work on it yourself , you will have to invest in a set of manuals. Way too many different applications to just pull timing settings etc out of the air. There are OMC gurus here that can help if you give serial numbers from the engine and drive. Are you well aquainted with the prev owner or know the reason the heads were done and the boat sold....Don't mean to sound negative, but if the heads were coming apart and the motor is knocking, you may have a tough row to hoe.....$$$$

 

[Kevin70]

Re: timing question and trouble shooting help

Yes, mechanical fuel pumps "tap" when they run. Some worse than others. If the armature is bent even a small amount, it can be even worse.

 

[michaelrj9]

Re: timing question and trouble shooting help

If your going to work on it yourself , you will have to invest in a set of manuals. Way too many different applications to just pull timing settings etc out of the air. There are OMC gurus here that can help if you give serial numbers from the engine and drive. Are you well aquainted with the prev owner or know the reason the heads were done and the boat sold....Don't mean to sound negative, but if the heads were coming apart and the motor is knocking, you may have a tough row to hoe.....$$$$

thanks for the responce.
I got the boat cheap because of known engine problems when we took it out for a drive.
Paid $6500 with a 2005 galvinized trailer.So I know I will have to put some $$$ into it.

The engine was replaced because he did not or did not know how to winterize it corectly and cracked the block.

The crate motor was from some place in Flordia.The man I bought it from said he lost the recipt (right) But I did take his old engine with the heads and he gave me a package of 14 replacement rocker arm studs that was from Flordia Because he was having a couple studs come loose.

So after we got it we pulled off the valve covers and we noticed 1 rocker arm stud came loose and the boss was cracked on 1 head so we decieded to replace both heads.

I did find the timming,points,idle settings in the owners manual.
But like I said above the noise I am getting now sounds like it is comming from the fuel pump.Just was wondering if anyone has heard of this happining.

Thanks

Michael

 

[searay3]

Re: timing question and trouble shooting help

As Kevin stated, fuel pump could tap if bent. Just a gasket and a couple of screws to hold it on. If you suspect it, yank it and have alook. You could either buy or make another gasket. Good luck and I hope it'll be reasonable to fix....

 

[Don S]

Re: timing question and trouble shooting help

Do yourself a favor and head to a local auto parts store and buy a mechanics stethescope for 10 bucks. Then find out where the noise is actually coming from.
If you are planing on keeping the boat, you will need it for the next noise.
Then post back with a discription or a picture of where the noise was the loudest. Then there is a possibility of figuring out where and what the noise is.