anyone with experience adjusting valves on 6 hp mercury

[rdhj]

my friend and i just did new piston rings, new valves, and gaskets to my no start 2007...we put it at TDC and adjusted the valves to the middle of the range but she wouldn't fire up. after checking them again, they seem to have tightened up..after messing with them we got it to start up for a couple seconds and then it died....the no start issue seems to have something to do with the position of the camshaft lobes not being in the right position when we make the valve clearance adjustment....anyone ever run into this and have any advice for getting the valve clearance correct. should we be setting them at the widest gap of the specification?

 

[raczekp1]

inside of the oilpan is a camshaft with ratchet.
one of the tooth has a mark.
the ratchet on the crankhaft has also a mark
this both marks has to be in line up together.
while assemling camhaft and a crankshaft did you line up those marks together?

valve clarence:

intake 0.06–0.14 mm (0.002–0.005 in.)
Exhaust valve 0.11–0.19 mm (0.004–0.007 in.)

 

[rdhj]

yes , we made sure the timing marks were lined up. just looked at how the cam lobes are positioned when at top dead center...they are in the bottom corners where the lobe is the widest...does that seem correct....as we have it set now, i can actually push the lifters off the lobes at TDC some....i am thinking that shouldn't be like that and that they should just be touching...am i correct? would it work if i tighten the adjusters all the way till the lifter just touch and then back them out to the proper spec?

 

[rdhj]

exhaust valve opens as intake valves is closing on compression stroke

just rebuilt my 2007 6 hp in an attempt to get it started...got new rings , valves and gaskets, but she wouldnt start...messed with the valve clearance and then noticed that after the engine takes in fuel and the intake valve is closing that the closed exhaust valve clearance disappears and the valve opens a little...this is giving me compression loss

so i put the engine right to where this started to happen and added the correct clearance to the exhaust valve....this is done a little before TDC, so at TDC, the exhaust clearance is alot...

it then started up and ran fine...however, i go to start it today and can't get it to kick over, it also feels like theres so much compression at a point in pulling that its hard to get a consistent pull without the motor itself pulling up in the bracket

so i checked the clearance again it is is the same story...exuast valve opening when it shouldnt be


am i missing something here or could something be bent like the crankshaft...we checked the pushrods and they were straight

 

[rdhj]

6 hp exhaust valve opens during compression stroke

just rebuilt my 2007 6 hp in an attempt to get it started...got new rings , valves and gaskets, but she wouldnt start...messed with the valve clearance and then noticed that after the engine takes in fuel and the intake valve is closing that the closed exhaust valve clearance disappears and the valve opens a little...this is giving me compression loss

so i put the engine right to where this started to happen and added the correct clearance to the exhaust valve....this is done a little before TDC, so at TDC, the exhaust clearance is alot...

it then started up and ran fine...however, i go to start it today and can't get it to kick over, it also feels like theres so much compression at a point in pulling that its hard to get a consistent pull without the motor itself pulling up in the bracket

so i checked the clearance again it is is the same story...exuast valve opening when it shouldnt be


am i missing something here or could something be bent like the crankshaft...we checked the pushrods and they were straight

 

[racerone]

There a compression release on this motor?------If so that might hold a valve open at cranking to reduce effort.----Need to look it up in your manual as to when exactly to set clearance on the valves.

 

[GA_Boater]

All your valve adjustment threads have been merged with this thread.

Are you removing the fuel pump to use the timing mark on the camshaft?

 

[rdhj]

Yes I took the fuel pump off and use the timing mark on the camshaft along with checking the Piston to make sure it was at top dead center. However the strange thing with this motor is at top dead center the mark which show on the diagram as being top dead center is not where mine lines up. mine Lines up with the mark on the other side of the crankcase. Also I'm not sure if this motor has a decompression nor does the manual say anything about a different way to set the clearance if it does. Any idea what the little metal plates with the spring on the camshaft is? Could that bepart of the decompression? Does anyone have a set of directions or know how to set the clearance for murders with the decompression?

 

[racerone]

Well,----That is the decompressor.-----That spring loaded gadget swings out of the way once motor is running !!

 

[rdhj]

Well,----That is the decompressor.-----That spring loaded gadget swings out of the way once motor is running !!

Is the procedure and specifications for setting the valve clearance the same for one without decompression or do all the six horsepowers have this

 

[raczekp1]

all 1 cylinder motors have decompresator on cam shaft

 

[rdhj]

hooked up my leak down tester today and at TDC, it was getting the same pressure in the head as what I was inputting into it. However, you could hear air in the crankcase. i am guessing the only thing that lets air in crankcase would be the rings.. these are new rings. still no start up...wondering if i am looking at the wrong things...seems like everything checks out but the timing marks lining up with with the wrong side of the crankcase.....and since the key is good i have no explanation for that....

anyone know what the 25 degree mark on the flywheel is used for....wondering if the repair book is wrong or someting

 

[Alumarine]

What manual are you using?

 

[rdhj]

Not at home and not forget the actual name I believe it seem or something like that it's the blue one that covers all the models

 

[Alumarine]

If it's not a mercury manual that might be the problem.
Here's a link to one, not sure if it's the right one.
http://boatinfo.no/lib/mercury/manuals/4-5-6.html#/0

 

[raczekp1]

this powerhead and outboard is built by Tohatsu/Nissan

 

[Mohawkmtrs]

Sounds like you have the piston at TDC on the EXHAUST STROKE.

The exhaust and intake valves should be closed at TDC on the COMPRESSION STROKE...and everything should line up.