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Onan issue

JR
Jon Roche
Tue, Sep 14, 2021 7:13 PM

Been going through alot of the troubleshooting guides multiple times.  This is a multi-year project.  common to tear into Ed's Generator at a Rally
to eventually end up at  a list of things to try.  Then those things get tried and problem still there.  It is just cursed!

I should also mention it has a dinosaur board.  We did toss a new board at it at one point.

I don't understand the condenser situation.  The bovee gets ride of the one that should sit next to points, but there is one that hangs on the coil,
and that is the one that is next on list to swap out.  Ed was trying to figure out where to buy and what part number for that one.  I am sure venders
have it, but would take a week to get at this point.  sometimes the local RV places that service onans can get them quick.

I re-read what sully stated,  and I think I will have to get some light bulbs hooked up to some wires with alligator clips.  Would be good to watch a
light bulb on the power feeding the fuel pump.  too bad they don't make a see through float bowl.

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/

Been going through alot of the troubleshooting guides multiple times. This is a multi-year project. common to tear into Ed's Generator at a Rally to eventually end up at a list of things to try. Then those things get tried and problem still there. It is just cursed! I should also mention it has a dinosaur board. We did toss a new board at it at one point. I don't understand the condenser situation. The bovee gets ride of the one that should sit next to points, but there is one that hangs on the coil, and that is the one that is next on list to swap out. Ed was trying to figure out where to buy and what part number for that one. I am sure venders have it, but would take a week to get at this point. sometimes the local RV places that service onans can get them quick. I re-read what sully stated, and I think I will have to get some light bulbs hooked up to some wires with alligator clips. Would be good to watch a light bulb on the power feeding the fuel pump. too bad they don't make a see through float bowl. -- Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
JR
John R. Lebetski
Tue, Sep 14, 2021 7:54 PM

METER for 12V+ at coil + with a clip lead.  If it stays there at same level when it dies, you do not need to throw a board at it.

John Lebetski
Woodstock, IL
77 Eleganza II

METER for 12V+ at coil + with a clip lead. If it stays there at same level when it dies, you do not need to throw a board at it. -- John Lebetski Woodstock, IL 77 Eleganza II
JR
Jon Roche
Tue, Sep 14, 2021 10:59 PM

Board was a few years ago.

Last weekend test showed good voltage at coil.  As well as timing light flashing away.    Also ran jumper to coil from battery and it still died.

Today hooked up pin9 to 5. Ran it and it died same way.

Again seems there is fuel.  This is like the 4-5th carb rebuild and 3rd carb.    This carb was sent down and rebuilt by jeff sirum.  And he said he
ran it on an onan and it worked fine.

I think it might be flooding itself out???  But i dont think the spark plugs really look wet.

Trying to hold open carb butterfly does not let it really restart.  You just have to walk away for 5-10 minutes and it will start up and run again.

I am thinking of holding a contest and offering $$ reward to anybody at gmcmi who can get this bugger to run for over an hour straight.

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/

Board was a few years ago. Last weekend test showed good voltage at coil. As well as timing light flashing away. Also ran jumper to coil from battery and it still died. Today hooked up pin9 to 5. Ran it and it died same way. Again seems there is fuel. This is like the 4-5th carb rebuild and 3rd carb. This carb was sent down and rebuilt by jeff sirum. And he said he ran it on an onan and it worked fine. I think it might be flooding itself out??? But i dont think the spark plugs really look wet. Trying to hold open carb butterfly does not let it really restart. You just have to walk away for 5-10 minutes and it will start up and run again. I am thinking of holding a contest and offering $$ reward to anybody at gmcmi who can get this bugger to run for over an hour straight. -- Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
L
Larry
Wed, Sep 15, 2021 12:43 AM

lqqkatjon wrote on Tue, 14 September 2021 17:59

Board was a few years ago.

Last weekend test showed good voltage at coil.  As well as timing light flashing away.    Also ran jumper to coil from battery and it still died.

Today hooked up pin9 to 5. Ran it and it died same way.

Again seems there is fuel.  This is like the 4-5th carb rebuild and 3rd carb.    This carb was sent down and rebuilt by jeff sirum.  And he said
he ran it on an onan and it worked fine.

I think it might be flooding itself out???  But i dont think the spark plugs really look wet.

Trying to hold open carb butterfly does not let it really restart.  You just have to walk away for 5-10 minutes and it will start up and run
again.

I am thinking of holding a contest and offering $$ reward to anybody at gmcmi who can get this bugger to run for over an hour straight.

I stood next to that thing and watched it while it slowly died. My gut feeling from observing and smelling  the exhaust is that it is a fuel problem.
If the carb ran good on another Onan, look up the line. Fuel pump? It is electric and could be failing as it heats up. Fuel line collapsing? Pick-up
in the tank plugged? Fuel line collapsing? Just seemed fuel to me, and considering you saw the timing light flashing as it quit....kinda illuminates
spark. JWIT

Larry
78 Royale w/500 Caddy
Menomonie, WI.

lqqkatjon wrote on Tue, 14 September 2021 17:59 > Board was a few years ago. > > Last weekend test showed good voltage at coil. As well as timing light flashing away. Also ran jumper to coil from battery and it still died. > > > Today hooked up pin9 to 5. Ran it and it died same way. > > Again seems there is fuel. This is like the 4-5th carb rebuild and 3rd carb. This carb was sent down and rebuilt by jeff sirum. And he said > he ran it on an onan and it worked fine. > > I think it might be flooding itself out??? But i dont think the spark plugs really look wet. > > Trying to hold open carb butterfly does not let it really restart. You just have to walk away for 5-10 minutes and it will start up and run > again. > > > I am thinking of holding a contest and offering $$ reward to anybody at gmcmi who can get this bugger to run for over an hour straight. I stood next to that thing and watched it while it slowly died. My gut feeling from observing and smelling the exhaust is that it is a fuel problem. If the carb ran good on another Onan, look up the line. Fuel pump? It is electric and could be failing as it heats up. Fuel line collapsing? Pick-up in the tank plugged? Fuel line collapsing? Just seemed fuel to me, and considering you saw the timing light flashing as it quit....kinda illuminates spark. JWIT -- Larry 78 Royale w/500 Caddy Menomonie, WI.
L
Larry
Wed, Sep 15, 2021 12:45 AM

Larry wrote on Tue, 14 September 2021 19:43

lqqkatjon wrote on Tue, 14 September 2021 17:59

Board was a few years ago.

Last weekend test showed good voltage at coil.  As well as timing light flashing away.    Also ran jumper to coil from battery and it still
died.

Today hooked up pin9 to 5. Ran it and it died same way.

Again seems there is fuel.  This is like the 4-5th carb rebuild and 3rd carb.    This carb was sent down and rebuilt by jeff sirum.  And he
said he ran it on an onan and it worked fine.

I think it might be flooding itself out???  But i dont think the spark plugs really look wet.

Trying to hold open carb butterfly does not let it really restart.  You just have to walk away for 5-10 minutes and it will start up and run
again.

I am thinking of holding a contest and offering $$ reward to anybody at gmcmi who can get this bugger to run for over an hour straight.

I stood next to that thing and watched it while it slowly died. My gut feeling from observing and smelling  the exhaust is that it is a fuel
problem. Seemed like it went slowly lean. If the carb ran good on another Onan, look up the line. Fuel pump? It is electric and could be failing as
it heats up. Fuel line collapsing? Pick-up in the tank plugged? Just seemed fuel to me, and considering you saw the timing light flashing as it
quit....kinda illuminates spark. JWIT

--
Larry
78 Royale w/500 Caddy
Menomonie, WI.

Larry wrote on Tue, 14 September 2021 19:43 > lqqkatjon wrote on Tue, 14 September 2021 17:59 > > Board was a few years ago. > > > > Last weekend test showed good voltage at coil. As well as timing light flashing away. Also ran jumper to coil from battery and it still > > died. > > > > Today hooked up pin9 to 5. Ran it and it died same way. > > > > Again seems there is fuel. This is like the 4-5th carb rebuild and 3rd carb. This carb was sent down and rebuilt by jeff sirum. And he > > said he ran it on an onan and it worked fine. > > > > I think it might be flooding itself out??? But i dont think the spark plugs really look wet. > > > > Trying to hold open carb butterfly does not let it really restart. You just have to walk away for 5-10 minutes and it will start up and run > > again. > > > > > > I am thinking of holding a contest and offering $$ reward to anybody at gmcmi who can get this bugger to run for over an hour straight. > > I stood next to that thing and watched it while it slowly died. My gut feeling from observing and smelling the exhaust is that it is a fuel > problem. Seemed like it went slowly lean. If the carb ran good on another Onan, look up the line. Fuel pump? It is electric and could be failing as > it heats up. Fuel line collapsing? Pick-up in the tank plugged? Just seemed fuel to me, and considering you saw the timing light flashing as it > quit....kinda illuminates spark. JWIT -- Larry 78 Royale w/500 Caddy Menomonie, WI.
CS
Carl Stouffer
Wed, Sep 15, 2021 3:57 PM

Two additional potential problems come to mind:

Fuel inlet in tank plugged as Larry suggested = starving for fuel.  Try blowing air through the line back into the tank with the gas cap off.

Too strong of a fuel pump, should be 2 - 3 PSI = flooding out as it gets hot.

Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging.  GMCSJ and GMCMI member

Two additional potential problems come to mind: Fuel inlet in tank plugged as Larry suggested = starving for fuel. Try blowing air through the line back into the tank with the gas cap off. Too strong of a fuel pump, should be 2 - 3 PSI = flooding out as it gets hot. -- Carl Stouffer '75 ex Palm Beach Tucson, AZ. Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
BM
Billy Massey
Wed, Sep 15, 2021 4:04 PM

Good call, Carl.  Mine was a perforated fuel line.  Started but wouldn't
maintain after it started.  It was sucking air.

bdub

On Wed, Sep 15, 2021 at 10:57 AM Carl Stouffer carljr3b@gmail.com wrote:

Two additional potential problems come to mind:

Fuel inlet in tank plugged as Larry suggested = starving for fuel.  Try
blowing air through the line back into the tank with the gas cap off.

Too strong of a fuel pump, should be 2 - 3 PSI = flooding out as it gets
hot.

Good call, Carl. Mine was a perforated fuel line. Started but wouldn't maintain after it started. It was sucking air. bdub On Wed, Sep 15, 2021 at 10:57 AM Carl Stouffer <carljr3b@gmail.com> wrote: > Two additional potential problems come to mind: > > Fuel inlet in tank plugged as Larry suggested = starving for fuel. Try > blowing air through the line back into the tank with the gas cap off. > > Too strong of a fuel pump, should be 2 - 3 PSI = flooding out as it gets > hot. >
TS
Todd Sullivan
Wed, Sep 15, 2021 4:31 PM

I believe that he stated earlier that he set up an alternate fuel supply (
separate fuel tank and line) and the problem remained unchanged.

Sully
Bellevue wa

On Wed, Sep 15, 2021 at 9:04 AM Billy Massey bdub.bdub@gmail.com wrote:

Good call, Carl.  Mine was a perforated fuel line.  Started but wouldn't
maintain after it started.  It was sucking air.

bdub

On Wed, Sep 15, 2021 at 10:57 AM Carl Stouffer carljr3b@gmail.com wrote:

Two additional potential problems come to mind:

Fuel inlet in tank plugged as Larry suggested = starving for fuel.  Try
blowing air through the line back into the tank with the gas cap off.

Too strong of a fuel pump, should be 2 - 3 PSI = flooding out as it gets
hot.


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I believe that he stated earlier that he set up an alternate fuel supply ( separate fuel tank and line) and the problem remained unchanged. Sully Bellevue wa On Wed, Sep 15, 2021 at 9:04 AM Billy Massey <bdub.bdub@gmail.com> wrote: > Good call, Carl. Mine was a perforated fuel line. Started but wouldn't > maintain after it started. It was sucking air. > > bdub > > On Wed, Sep 15, 2021 at 10:57 AM Carl Stouffer <carljr3b@gmail.com> wrote: > > > Two additional potential problems come to mind: > > > > Fuel inlet in tank plugged as Larry suggested = starving for fuel. Try > > blowing air through the line back into the tank with the gas cap off. > > > > Too strong of a fuel pump, should be 2 - 3 PSI = flooding out as it gets > > hot. > > > _______________________________________________ > GMCnet mailing list > Unsubscribe or Change List Options: >
CS
Carl Stouffer
Wed, Sep 15, 2021 9:23 PM

Good point, Sully.  Fuel starvation must not be the problem, at least not due to a restriction in the pick-up.

Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging.  GMCSJ and GMCMI member

Good point, Sully. Fuel starvation must not be the problem, at least not due to a restriction in the pick-up. -- Carl Stouffer '75 ex Palm Beach Tucson, AZ. Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
JH
James Hupy
Wed, Sep 15, 2021 9:55 PM

I have had many years of experience with air cooled, valve in block
engines, and over time I have encountered several instances of expanding
engine blocks that "used up" all the valve to valve tappet clearance when
they got hot. This would prevent the valve, or valves, from opening fully
and no fuel mixture or not enough fuel mixture could enter the cylinder.
Then the engine acts like it is running out of gas, which it is, but for a
different reason. One of my John Deere riding mower with a Kohler engine
did this, and it took me quite a while to figure out what was going on.
Cure? Grind a bit more clearance off the end of the valve stem. Worked for
me.
Jim Hupy
(Retired Vocational Instructor in Small Engines and Power Mechanics)
Salem, Oregon

On Wed, Sep 15, 2021, 2:23 PM Carl Stouffer carljr3b@gmail.com wrote:

Good point, Sully.  Fuel starvation must not be the problem, at least not
due to a restriction in the pick-up.

Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive,
Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American
Eagles,
Solar battery charging.  GMCSJ and GMCMI member


GMCnet mailing list
Unsubscribe or Change List Options:

I have had many years of experience with air cooled, valve in block engines, and over time I have encountered several instances of expanding engine blocks that "used up" all the valve to valve tappet clearance when they got hot. This would prevent the valve, or valves, from opening fully and no fuel mixture or not enough fuel mixture could enter the cylinder. Then the engine acts like it is running out of gas, which it is, but for a different reason. One of my John Deere riding mower with a Kohler engine did this, and it took me quite a while to figure out what was going on. Cure? Grind a bit more clearance off the end of the valve stem. Worked for me. Jim Hupy (Retired Vocational Instructor in Small Engines and Power Mechanics) Salem, Oregon On Wed, Sep 15, 2021, 2:23 PM Carl Stouffer <carljr3b@gmail.com> wrote: > Good point, Sully. Fuel starvation must not be the problem, at least not > due to a restriction in the pick-up. > -- > Carl Stouffer > '75 ex Palm Beach > Tucson, AZ. > Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, > Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American > Eagles, > Solar battery charging. GMCSJ and GMCMI member > _______________________________________________ > GMCnet mailing list > Unsubscribe or Change List Options: >