Powerpack?

[Orval]

70hp Evinrude 70673D...120 on all 3 cylinders (before warm up)

I have new pistons, rings, rectifier, coils, fuel lines and tank, spark plugs, fuel pump, rebuilt and cleaned carbs many times, rejetted per Boyesen reeds recommendations , no water leaks, do not see any fuel leaks.

rebuilt it...started it up...the manual says to set the carbs closed..did it...set cam on mark...did it...and while in the tank and in forward gear set the pick up timing to 3*-5* ATDC. There are no marks on flywheel for ATDC so I measured the timing marks BTDC and measured over the same distance on the ATDC side and scribed a mark and set it there. idles fine.

When I try to give it the slightest bit of throttle, it immediately bogs down and dies. I've pumped the primer, tried going really slow, ...I don't want to ruin the motor.

What am I doing wrong here? Could a powerpack do this?

Any help is appreciated, Thx

 

[interalian]

When you say "give it the slightest bit of throttle", do you mean moving the throttle lever or just trying to open the carbs. If the latter, bogging is due to fuel overload with too little spark advance. If the former, your link/sync needs to be reviewed. I would suggest finding the OE service manual if you don't already have it.

 

[racerone]

Sounds like throttle plates are opening too early.-----If spark jumps a gap of 7/16" or more powerpack is good and has nothing to do with the stalling.----You have cleaned the carburetor 5 times and high speed jets in the bowls must be clean by now.------Issue is throttle plates opening too early in my opinion.

 

[Orval]

The manual I have is a Seloc

I have followed it to a tee as far as I can tell.

It bogs down both ways, although if I feather the throttle at the carbs it sometimes will rev a little.

I really don't want to break this thing is why I just stopped and came to the forum

 

[Orval]

So ...do I just back the roller off of the cam a little more?

 

[racerone]

There usually is a space between roller and cam at idle.----Costs you nothing but time to adjust and test run with adjustment there.

 

[interalian]

The seloc manual is good only for light reading and possibly if you run out of TP. Find an OMC Service Manual - it'll pay for itself. Check your local library - mine had copies for many years.

 

[Orval]

I backed the cam off a little. Started...and moved the throttle lever and it started to die...so I hit the choke switch and it took off...(I did not let go too far)…
Does that mean it is not getting enough fuel?

 

[racerone]

You removed the high speed jets that are screwed into the bottom of the float bowls ?---What number is on them ?----If it takes of with operation of choke it does point to lack of fuel.

 

[Orval]

54 d

 

[racerone]

The float bowl gasket is one piece or 2 pieces with a separate gasket around the nozzle ?

 

[Orval]

float bowl gasket is a one piece

 

[Orval]

low speed orifice (air idle) was changed per Boyesen reed instructions. Down I think 5 sizes

 

[racerone]

Is there a gasket around the nozzle in the carburetor body ??

 

[Orval]

yes

 

[racerone]

Put the original low speed orifice back in for a test.

 

[racerone]

Are you sure that the idle orifice is for air on your motor ??

 

[Orval]

yes. And no adjustment. Just changes in size.
Will the original jets hurt the reeds?

 

[racerone]

I probably have a few carburetors like that.----Are you sure they are air jets , yes , no , maybe ?----I have no experience installing fancy reeds.----Saw those plastic reeds bucked on a motor once and that was enuff to dismiss the claims made by folks who swell this stuff.----Stainless reeds are good for me.

 

[Orval]

not sure now. I thought that they were