96 johnson 150

[Chuck4741444]

have been through the fuel system, twice, i have wired every whole in the throttle plate, and carbs, check flat levels, blew air through every thing,

Thanks for you response,
I'm going to run an electric fuel pump next week, If it helps, ill replace the fuel pump, one question, were does the fuel pump gets it vacuum from? can it be checked with a vacuum gauge?

 

[saltchuckmatt]

Electric fuel pump is not needed. Pump on the primer ball when testing and if it clears up then replace fuel pump. Fuel pump works on pulses from the crank case.

No vacuum in there. (Piston skirts)

 

[racerone]

Nothing wrong at 105 PSI

 

[racerone]

Fuel pumps run with PRESSURE pulses from the crankcase of one cylinder.

 

[Faztbullet]

They never made a low compression motor..just low compression heads. Powerhead is mechanically the same between commercial and recreational motors. Also no covers to remove for inspection

 

[saltchuckmatt]

They never made a low compression motor..just low compression heads. Powerhead is mechanically the same between commercial and recreational motors. Also no covers to remove for inspection

Thanks for the correction....what about the hole Race talks about.

 

[Faztbullet]

.what about the hole Race talks about.

All looper motors since1992 has this 1/8" hole right at the exhaust port. It is a idle relief port and drops compression about 10psi at idle. Compression will build back at speed. Us performance guys tap and plug it with a allen screw and then stake aluminum around it to prevent it from backing out. Helps us get er out of the hole quicker! Mercury uses a milled slot in sleeve for same purpose.

 

[Chuck4741444]

Fuel pumps run with PRESSURE pulses from the crankcase of one cylinder.

I'm running mixed fuel. the vro pump was removed, i may have the fuel lines from the vro mixed up.
pumping the bulb doesn't help, and i removed the fuel rail on one side, fuel pump is working., is there a way to by pass the exiting fuel pump and vapor separator? i found the product online,

Earlier this week i took it out, the idle was 1100 and rough, but it ran great at wot and half throttle, then back to rough idle. i pulled the carbs, checked for a problem, took it out Friday, it fell flat on its face, idle was bad and it died when i shifted in to gear, Friday night i pull the left side of the moter, including reads, everything is clean, All carburetors had fuel in the bowls, each time i removed them,
i put it back in my test barrel Saturday and it worse, then swapped #1 and #3 carbs, ( # 3 was firing before and after the swap) no change on #1
the hose from the bottom is connect to a new pulse limiter, the top hose is connected at the top of the crank case.
stating yester day, when i prime with the ball, fuel is coming from a 1/8 barb on the top of the sq device that feeds the primer lines, i have a a factory manual, but there's not enough details on where this lines go,
Johnson/Evinrude/OMC New OEM No VRO Fuel Pump PreMix Conversion Kit 5007422

 

[Chuck4741444]

All looper motors since1992 has this 1/8" hole right at the exhaust port. It is a idle relief port and drops compression about 10psi at idle. Compression will build back at speed. Us performance guys tap and plug it with a allen screw and then stake aluminum around it to prevent it from backing out. Helps us get er out of the hole quicker! Mercury uses a milled slot in sleeve for same purpose.
View attachment 402145

 

[Chuck4741444]

I have quality spark on all six cylinders, Is it even possible that the Power pack is malfunctioning and just randomly firing?
I know it sounds crazy, but if cylinder #1 is firing @6 degrees btc, could i put the trimming light on the others in the firing order and mark the timing wheel to see if moving in the proper increment through the 360 Degrees

 

[racerone]

That procedure is done all the time.-----Mark TDC for each cylinder and check the firing.----Perhaps wires from powerpack to coils are mixed up.

 

[Faztbullet]

Cant really test with timing light can cause optical sensor to read incorrectly. Need the timing tool to accurately set timing but the encoder wheel is already indexed

 

[Chuck4741444]

That procedure is done all the time.-----Mark TDC for each cylinder and check the firing.----Perhaps wires from powerpack to coils are mixed up.

To day i removed and cleaned every hole in the throttle plate, swapped reeds around, and by passed the fuel system, using an electric fuel pump, it running on 2 cylinders as before, i have a power pack from a parts motor, however, 4 of the six wire the connect to the coil have been cut, i hate to cut mine off to replace them, there is enough wire left that i can see the colors on the wires,
Will the wire work with soldiered wires? will it carry enough current for the coils?

 

[saltchuckmatt]

To day i removed and cleaned every hole in the throttle plate, swapped reeds around, and by passed the fuel system, using an electric fuel pump, it running on 2 cylinders as before, i have a power pack from a parts motor, however, 4 of the six wire the connect to the coil have been cut, i hate to cut mine off to replace them, there is enough wire left that i can see the colors on the wires,
Will the wire work with soldiered wires? will it carry enough current for the coils?

Do what you must do.

Current will be the same if done correctly.

 

[Chuck4741444]

Do what you must do.

Current will be the same if done correctly.

I used another CDI and checked the magnets under the flywheel, all that is left is compression related, I'm buying a new compression gage tomorrow, i can't find the compression needed for my motor in the service manual motor is a 96 j150exedb.
Thanks for everyone's input

 

[Faztbullet]

problem: rough idle \ runner good at wot 21 ft. CC running 32 mph that's what it was before rebuild

Our pistons on correct sides...seen something similar with a Merc 200 V6

 

[saltchuckmatt]

Your looking for a minimum of around 100 but hopefully more around 120. Up to 130 or 140 would be fantastic.

Mainly you want them within 10% of each other.

 

[Faztbullet]

Most you will ever see is about 105-108psi at cranking speed. These motors will never see 120psi+ at cranking. Most motors read 95-105psi

 

[racerone]

Lots of mis-information on compression in 2 strokes.----see post #23 and #38.

 

[Keyboardman]

I have a 1996 Evinrude 200 Ocean Pro and it only has 105 to 100 psi. It also runs like a Tiger pushing my old 21' Dixie WA to 43Mph. : )