| Author |
Message |
    
Ricardo Guillen
Member
Username: jiggamurf
Post Number: 21
Registered: 08-2009
| | Posted on Tuesday, October 27, 2009 - 03:35 pm: | 
|
i have this 1993 evinrude 40hp. the engine is very difficult to start when cold or hot and when i finally get it to start it runs very rough spitting a mist of fuel mixture thru the top carb. when i unplug the top spark plug (while running) then engine runs fine with the bottom cylinder. but when i connect the top plug again its start sputtering. and kicking, spitting out the top carb and finnaly dies. compression is 120 on both cylinders. spark jumps 7/16 gap clean. new spark plugs, i cleaned carburetors, and replaced carburetors with well known extras i had in shop and problem still consists. the vro was finally bypassed and fed straight fuel/oil mixture 33/1. and problem is still there. reed valves were pulled and cleaned and reassembled and problem is still there. im out of ideas. im starting to think timing or internal problems?
anyone? got ideas?
thanks |
jwbmarine
Senior Member
Username: jwbmarine
Post Number: 5073
Registered: 11-2005
| | Posted on Tuesday, October 27, 2009 - 08:27 pm: |
|
this,should be a 2cyl....those blocks,..are the same,as the old 50's 30 yrs ago...it is extremely possible,u have a bad seal,between the 2 cyl's....a labryinth,seal...i would be surprised to see a prob of such,on an eng so new,..however,..it occurs in numbers,and causes th eprob's u see..timing,...unless,..a sheared flywheel key,...is not,ur prob |
Morten Ringvold
Senior Member
Username: haffiman37
Post Number: 4316
Registered: 04-2006
| | Posted on Tuesday, October 27, 2009 - 08:41 pm: |
|
My guess is that you may have a 'double firing' power-pack.
In plain text, the PP fires both cylinders at the same time.
You may need a timing light and check.
Hook it to top cylinder Make a mark at cyl 1 and one 180 degree (opposite) on the fly-wheel. If you see both top and bottom cyl marks at the same time, change power pack. |
Richy
Member
Username: jiggamurf
Post Number: 23
Registered: 08-2009
| | Posted on Wednesday, October 28, 2009 - 12:44 am: |
|
the more i run it the weirder it gets. it keeps spitting out the top carb. the bottom carb seems to run fine. i put clear hoses to verify fuel is getting to carbs and the top carb is slowly developing bubbles. till the fuel line has no more fuel. then the engine enrichens (keeps running because of the bottom cylinder. i finally pump the primer bulb (with 33?/1 mix fuel just in case the vro is not working) and the top carb fills up again and it spits and kicks for a little then stablizes but eventually runs out of fuel again on the top carb. all this time the bottom carb remains with fuel. not eaven one air bubble. when both carbs are full i pull plug wires for each cylinder and the engine continues to run on the other cylinder with very little almost no spitting back thru carb.
my question is can i replace the vro and install a regular fuel pump and just start mixing my fuel at the tank?
i just dont know if i should trust that vro while im at the lake. it doesnt seem reliable |
Morten Ringvold
Senior Member
Username: haffiman37
Post Number: 4318
Registered: 04-2006
| | Posted on Wednesday, October 28, 2009 - 03:11 am: |
|
It might not be the VRO itself.
If you are using a separate tank, check the O-ring in the fuel connector. A small crack and replace.
Normaly this will result in an 'over-oiling' situation as the VRO keeps pumping oil, but not much fuel. Does the engine start smoking excessively?
Be sure to correct the lack of fuel as quick as possible or you will suffer a melted piston due to lean burning. |
Tim Lyden
Member
Username: tal55lyd
Post Number: 23
Registered: 11-2007
| | Posted on Thursday, November 05, 2009 - 09:15 pm: |
|
float may be sticking? reed valve open, how the compression on top cyl, bad ring blow by? hole in piston |
Tim Lyden
Member
Username: tal55lyd
Post Number: 24
Registered: 11-2007
| | Posted on Thursday, November 05, 2009 - 09:16 pm: |
|
Sorry I see u check compression |
jwbmarine
Senior Member
Username: jwbmarine
Post Number: 5098
Registered: 11-2005
| | Posted on Thursday, November 05, 2009 - 09:22 pm: |
|
all the above is good info...is this eng running ok?...some eng's/carbs do spit back,..my idea,of excessive,spitback,..may be diff,..than ur's..the 'blowback',prob,..is tried to be,handled,by the lower hose on breather...rarely do i see one,..that is oil free,etc.on bottom pan,due to spitback...they all,..some more apparent than others,do that,...its the nature of reed valves. |
jwbmarine
Senior Member
Username: jwbmarine
Post Number: 5099
Registered: 11-2005
| | Posted on Thursday, November 05, 2009 - 09:23 pm: |
|
ur vro.is not the prob w/spitback |
jwbmarine
Senior Member
Username: jwbmarine
Post Number: 5100
Registered: 11-2005
| | Posted on Thursday, November 05, 2009 - 09:26 pm: |
|
a dbl firing pwr pack,..is possible,..but i have never seen it on a 2 cylinder,in 32 yrs.and i have touched 1-or 2.....bad packs,arcing coils,etc,etc,.... |
Morten Ringvold
Senior Member
Username: haffiman37
Post Number: 4340
Registered: 04-2006
| | Posted on Thursday, November 05, 2009 - 09:47 pm: |
|
'but i have never seen it on a 2 cylinder,in 32 yrs'
I've seen them a lot, in less time.
May be caused by the pack itself, but just as often caused by 'arching' in the Amphenol contacts between Power-pack and trigger/stator. Rather confusing if you test the pack on another engine, everything is fine! |
jamie campbell
Advanced Member
Username: outboard_doctor
Post Number: 715
Registered: 02-2009
| | Posted on Friday, November 06, 2009 - 12:33 am: |
|
If you mark the flywheel at tdc with white out and place a number two 180 deg opposite of the tdc mark, run the engine with the timing light on number one cylinder, if you have a double firing power pack you will see both marks at the same time. |
