Not reaching max RPM!!!

[ddbyrd3]

Re: Not reaching max RPM!!!

This has been an issue since rebuild in "01", its a long story... I had a previous thread "engine swap" where DHadley walked me thru verifing piston install position, compression, ignition, etc. Now I am just trying to get into the fine details as to what could be the reason for the RPM loss...<br /><br />The engine builder is a knucklehead and says there is nothing wrong with the motor.... with DHadley's help I found the timing off, he never went thru the carbs, etc so I am hoping I will find what he missed eventually....<br /><br />The motor in on a 1980 Glastron Galaxie 19' deep "V"... Its a fairly light boat.....

 

[ddbyrd3]

Re: Not reaching max RPM!!!

Another question, as you can see I am grasping at straws now....<br /><br />Fuel system.. My primer ball pumps up hard and stays hard all day long....<br /><br />Even under these circumstances, could the fuel pump not be supplying enough fuel causing the motor to starve and not to reach max RPM????

 

[Basscat 1]

Re: Not reaching max RPM!!!

After 10 hrs running time, you are suppose to go back and re-torque the heads.<br />Have you tried running at wot with the hood cover off?

 

[ddbyrd3]

Re: Not reaching max RPM!!!

I did retorgue the heads, all was good.. No I have never ran without the hood on.... Are you suggesting a possible air restriction???<br /><br />The air inlet under the handle is clear I did check that....

 

[Basscat 1]

Re: Not reaching max RPM!!!

No I am suggesting a possible exhaust leak that is drowning your engine with exhaust fumes.<br />Possibly when the power head was pulled off for the rebuild, they didnt get it sealed between the power head and adapter, thus the leak.<br />Give it try, just another stone to turn over.

 

[ddbyrd3]

Re: Not reaching max RPM!!!

I will try that... I have never seen or suspected that to be a problem, what are the signs of an exhaust leak on an outboard???? <br /><br />I have pulled off my engine cover to adjust idel, etc, and I never smelled exahust fumes....<br /><br />But I am willing to try anything at this point...

 

[Basscat 1]

Re: Not reaching max RPM!!!

If it runs better with the cover off, that is a sign of an exhaust leak. It happens.

 

[ddbyrd3]

Re: Not reaching max RPM!!!

There is no visible signs of an ehxaust leak though????? Other than drowning the motor with exhaust????

 

[Basscat 1]

Re: Not reaching max RPM!!!

Usually not. You can use dish soap mixed with water in a spray bottle and spray it around the base of the power head with the engine running and look for bubbles.<br />Try running it with the cover off first and see what happens.

 

[ddbyrd3]

Re: Not reaching max RPM!!!

I'll do that..... thanks for the info.....

 

[ddbyrd3]

Re: Not reaching max RPM!!!

I pulled the heads off of my motor... The head gaskets I pulled off were BROWNISH / RED color.. They also said "use on 115 - 135 hp" engines.<br /><br />I am not too worried about color, but are these head gaskets the same between a 115-135hp johnny and a 140 johnny???<br /><br />Also I noticed #1 cylinder was not as wet (the piston) as numbers 2, 3, & 4. I took pics to post but I have to wait till tomorrow...<br /><br />Other than that all looked good nothing out of the ordinary except #3 has a .020 over piston in it.........

 

[ddbyrd3]

Re: Not reaching max RPM!!!

How do you post pictures????????

 

[walleyehed]

Re: Not reaching max RPM!!!

I am not too worried about color, but are these head gaskets the same between a 115-135hp johnny and a 140 johnny???<br />

90-140 was all the same block, heads are simular, some have higher comp. Gaskets are the same, I believe.

 

[Basscat 1]

Re: Not reaching max RPM!!!

How do you post pictures????????

Go to this web site. web page <br />Click on browse and download your picture from your pc. It will then give you a direct link to your photo. Copy the link.<br />To post it here, you have to go to "post a reply" bottom left of this website, under that click on image. Paste your direct link here.<br /><br />What happened when you ran it without the cover?

 

[ddbyrd3]

Re: Not reaching max RPM!!!

Thanks for the replys guys.. I will post pics later.....<br /><br />About the head gaskets, i was hoping the ones I installed would allow for higher compression (thinner gasket) I will be re checking the compression today as well.....<br /><br />I havent had a chance to run it without the cover.. Hopefully this week, I just wanted to remove another peice of the puzzle by changing the head gaskets..

 

[ddbyrd3]

Re: Not reaching max RPM!!!

 

[Basscat 1]

Re: Not reaching max RPM!!!

Also I noticed #1 cylinder was not as wet (the piston) as numbers 2, 3, & 4. I took pics to post but I have to wait till tomorrow...<br />

I would make sure cylinder #1 is not running lean.

 

[ddbyrd3]

Re: Not reaching max RPM!!!

<br /><br />This is the #1 cylinder, it looks dry and slightly rusty, looks like it may have been taking on water.... But I am far from an expert.. Any ideas??<br /><br />THAT DIDNT WORK, let me try again..

 

[ddbyrd3]

Re: Not reaching max RPM!!!

[/URL][/IMG] <br /><br />See if that works..

 

[ddbyrd3]

Re: Not reaching max RPM!!!

[/URL][/IMG] <br /><br />Here is a second shot of the same piston.. #1.