not getting up to full speed

[bigd5977]

Re: not getting up to full speed

YES on everything you covered about the carbs too

 

[bouttime007]

Re: not getting up to full speed

Maybe your fuel line is bad or has a small leak? It is able to get enough fuel until it gets to 3/4 or wide open throttle, at which point it starts sucking air and is starved for fuel. Just a guess.

This is what I was thinking too.

If there are fuel fittings without clamps (like was mentioned earlier), Id say clamp them suckers so it isnt sucking air.

 

[bigd5977]

Re: not getting up to full speed

they are clamped,, i'm a mechanic from way back & KNOW THAT ALL FUEL LINES NEED TO BE CLAMPED

 

[archcycle]

Re: not getting up to full speed

pulled the high speed orifices and made sure they were not plugged or restricted?

+1 on the high speed jets.

Take these out and spray some cleaner through the passages, wait a minute, and blow them out with low pressure (30psi or so) compressed air.

I read through all of this earlier but I can't remember, did you ever pre mix some fuel/oil in a spray bottle, get it on the water, put it to WOT, and spray it down one throat at a time and see if it either bogged or picked up or no change?

 

[bouttime007]

Re: not getting up to full speed

they are clamped,, i'm a mechanic from way back & KNOW THAT ALL FUEL LINES NEED TO BE CLAMPED

Well you mentioned some didnt have clamps before, and you mentioned seeing air bubbles in the line. First thing I thought of was that its sucking air.

Did one or more of the jets get turned by mistake?

 

[bigd5977]

Re: not getting up to full speed

yes on the bottle mix & no difference, & yes at first when i got the boat the fuel lines were not clamp & i clamp them,, all carbs have been thoroughly gone thru, cleaned & blown out, & how can a jet get turned my mistake,, i took them out, clean them & put them back in,, & yes on the pump bulb, no difference & yes all linkages are linked & synch ,, getting a headache on this thing anymore trying to figure it out

 

[archcycle]

Re: not getting up to full speed

I almost hate to ask, but based on our back and forth in the "joe reeves timing question" thread a few minutes ago, are you sure your WOT timing is set correctly?

 

[Daviet]

Re: not getting up to full speed

As I said before, if your compression is good. The spark jumps a 7/16" air gap, your problem has to be a fuel delivery problem.
If the fuel pump is operating properly, all lines and fittings are tight the only thing left is the carbs.

Another thought, have you checked the pulse hose for the fuel pump to see if there is any gas in it?

 

[bigd5977]

Re: not getting up to full speed

ummmmmmmmmm,, the PULSE HOSE ??? what is that ?? where is that?? & which 1 of the 3 hoses that goes to the fuel pump is it ???,,, should gas be in it at all time ?? running & not running,, cuz i'm not going top take a fuel line off when boat is going down the lake, & for safety ,, i should shut the motor off , so NO FIRES get started

 

[Daviet]

Re: not getting up to full speed

NO, don't pull the fuel lines with the engine running. You have three hoses on your fuel pump, fuel in, fuel out and one that goes to the block. The one that goes to the block is the pulse hose, it makes the fuel pump pump. If the diaphram in the fuel pump is defective it will allow fuel into the pulse hose and extra fuel into the cylinder that operates it makeing that cylinder run real rich and cause problems.
Just another thought.

 

[bigd5977]

Re: not getting up to full speed

oh ok,, that's the 1 that is what i called the vacuum hose operating the fuel pump,, i know which 1 you mean now & NO THERE HAS NEVER BEEN ANY FUEL IN THAT LINE

 

[oldrudedude]

Re: not getting up to full speed

hmm

 

[oldrudedude]

Re: not getting up to full speed

ok,, all testing done with timing light, compression tester & everything is good to go ( ON THE TEST ),, but still takes a bit to get warmed i guess or for the motor to get the boat moving,, i am told now that if i can squeeze the fuel bulb while its running & the bulb is not firm already & i go back again to squeeze it when its acting up & i can squeeze it again to get firm,, it means the FUEL PUMP is not working right & needs to be REBUILT or new pump put on,,, so next question is,, what is the difference between a 75ELR77S fuel pump & a 75ELR77 pump ????? please help,, TY

The primer bulb normally goes soft when the engine is running because the line is then under vacumm not pressure. It does NOT mean you need a new fuel pump.

 

[oldrudedude]

Re: not getting up to full speed

I almost hate to ask, but based on our back and forth in the "joe reeves timing question" thread a few minutes ago, are you sure your WOT timing is set correctly?

Agree with archcycle. On outboard motors the timing has to be set twice. Once at idle (usually around 0* but depends on the spec of your motor). Idle timing can be done on muffs in the driveway. Timing also has to be set at full advance (I think you mensioned 18*). Full advance timing should not be performed with the engine running and wide open throttle unless it is done in a test tank or with other appropriate equipment, because you run the risk of doing serious damage to your engine by running it wide open without a load. That is why most home outboard mechanics use the "Joe Reeves WOT timing method" This method allow you to do the full advance timing with the engine off and the plugs out while cranking the starter. You can find a description of this method in the sticky file labelled "Top Secret" at the top of the Johnson/Evinrude page.

Good luck.

 

[bigd5977]

Re: not getting up to full speed

oh ok,, hold on a min. here,,, NOBODY told me or said anything to me about an OUTBOARD motor needed to be TIMED TWICE,,, my motor has the tag on it for 16* & that is where it is timed at & all the books & service rep's & the marina told me that was right & correct when they double checked my worked.. BUT NOBODY told me it HAD to be done TWICE,, so i guess i owe an apology to a couple people on here about this other way, but they owe me 1 too cuz i was right on my part for what i did,,, anyways,, so now i need to check this JOE REEVES TIMING thing out & see how to do it,, now you say this is on ALL OUTBOARD motors, regardless of what yr it is,, cuz mine is a 77 Johnson 75 hp & was also told it was a Stinger, so now i have to double check & see if this timing is right too ????

 

[bigd5977]

Re: not getting up to full speed

ok,, so do i go by this JOE REEVES thing to do the WOT timing or not & i don't know if my motor has this QUICK START feature or not,, mine motor is a 77 Johnson 75hp & the timing tag says 16*,, now is this idle timing or WOT timing,,,, very confused now,, PLEASE HELP ME

 

[archcycle]

Re: not getting up to full speed

That will be WOT timing

 

[oldrudedude]

Re: not getting up to full speed

I don't think your motor has quick start, but to be sure you should check your manual.

 

[jimmy120]

Re: not getting up to full speed

Check the stator. I bet its bad.

 

[oldrudedude]

Re: not getting up to full speed

Bigd5977, The idle and Wot timing are set with two different screws. The idle timing is set with a screw located on the engine throttle arm just above the pivot. This screw prevents the throttle arm (and timing) from dropping back too much when the engine is throttled down. It is actually a throttle (timing) return stop screw. The Wot timing is set with a stop screw at the top of the engine (on the engine casing just under the flywheel). It prevents the throttle arm (timing) from advancing too far forward when the throttle is opened. The timing is physically adjusted by the position of the throttle arm. There are no centrifical weights or vacumn diaphrams involved. Timing advance is determined by the position of the lever. That is it. The two timing settings are simply setting the range the throttle lever is allowed to move through. Idle timing can be set with the engine running on muffs. The WOT timing should not be set with the engine running because revving at that high rpm without a load on the engine can cause runaway and serious damage. That is why WOT tiiming is done at with plugs out and grounded at cranking speed only, with the throttle arm at the full advance position. You don't want the engine to start when you are doing this type of WOT timing.