Recently picked up this 75 400 and had no spark. I supposedly ran 2 years ago when parked. But I have got enough stuff over the years that I take that with a grain of salt.
:blink:
After assistance from great info on our site here traced back to a possible points issue.
Removed recoil and pulley and cover. Looked through 2 windows on flywheel and could see points needed some attention. Cleaned points through windows without flywheel removal. Then simply did re-assemble to test for spark. The missing spark has returned to both sides now. It looks to be a fairly good healthy arc.
Problem is now with a small bit of fuel down in each cylinder and pull to hear it bark a bit all get from it is backfiring through exhaust and odd time through carb.
I would really think the timing is off, but hey maybe wrong.
1) But what I did for removal should not of affected timing at all right ?
2) Can you suggest anything else ?
Points assembly kinda look nice and shiney wondering if have been replaced by previous owner and timing is off.
Since I do not as of yet have a service manual for it. Can some one suggest some help or describe the do's and don'ts for setting timing on this thing.
Any suggestions would be very welcome.
Thanx Dave
1975 JD 400 backfiring ?
-
JDCornFlakes
- Posts: 447
- Joined: Tue Apr 04, 2006 12:00 am
- Location: SW Ontario, Canada
1975 JD 400 backfiring ?
DAVE
From Ontario...That's in Canada not in California eh !
From Ontario...That's in Canada not in California eh !
-
400brian
- Posts: 5626
- Joined: Wed Jul 20, 2005 12:00 am
- Real Name: James T. Kirk
- Location: South Central Wisconsin
1975 JD 400 backfiring ?
Timing procedure is in the FAQs.
Are you sure you have the wires on the correct plugs?
Are you sure you have the wires on the correct plugs?
'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
-
JDCornFlakes
- Posts: 447
- Joined: Tue Apr 04, 2006 12:00 am
- Location: SW Ontario, Canada
1975 JD 400 backfiring ?
You know Brian , I was thinking of that driving home today. In the wiring diagram it shows the white wire for coil #1 and red wire to coil #2 . But maybe I should just trace them. I think one coil at one time has been change as the coils both have red wires coming out of them and one spare coil I have has a white wire.
Will verify and then will attempt the timing procedure that I really hope is not needed after the plug wire check.
My son is kinda bummed that it does not fire up. So if can get it running before storing it will make him and Daddy feel a bit better.
Thanks Brian for replying , I do appreciate it much !
Thanx Dave
Will verify and then will attempt the timing procedure that I really hope is not needed after the plug wire check.
My son is kinda bummed that it does not fire up. So if can get it running before storing it will make him and Daddy feel a bit better.
Thanks Brian for replying , I do appreciate it much !
Thanx Dave
DAVE
From Ontario...That's in Canada not in California eh !
From Ontario...That's in Canada not in California eh !
-
JDCornFlakes
- Posts: 447
- Joined: Tue Apr 04, 2006 12:00 am
- Location: SW Ontario, Canada
1975 JD 400 backfiring ?
Holy frig guys never believe this !! I traced the wiring to be sure I did not have the plugs wires backwards. All the way from points to coils and up to plugs all checked Ok.
So I thought will try cleaning and blowing out points a 3rd time. Well went from having spark and backfiring to NO SPARK AT ALL !!
Then took apart a 4th time and thought well try filing them again and sprayed with some switch and contact cleaner I have had much luck with before called Nu-Trol.
Well after the 4th time put back together and bit of fuel and away she barked. The thing that amazed me was how the points being dirty/ corroded or whatever made it act like timing was off!!
Just goes to she ME that about when ya think all is good is not really !!
The product Nu-Trol is amazing stuff developed to military specs for the U.S Air Force is has a light oil based carrier that holds it to contacts to continue cleaning for up to 30 days. Where most contact cleaners will evaporate due to their alcohol base.
Whoa what real nice feeling to here the ole girl bark like that...sprayed some fuel in carb and ran a bit.
Thanx Dave
So I thought will try cleaning and blowing out points a 3rd time. Well went from having spark and backfiring to NO SPARK AT ALL !!
Then took apart a 4th time and thought well try filing them again and sprayed with some switch and contact cleaner I have had much luck with before called Nu-Trol.
Well after the 4th time put back together and bit of fuel and away she barked. The thing that amazed me was how the points being dirty/ corroded or whatever made it act like timing was off!!
Just goes to she ME that about when ya think all is good is not really !!
The product Nu-Trol is amazing stuff developed to military specs for the U.S Air Force is has a light oil based carrier that holds it to contacts to continue cleaning for up to 30 days. Where most contact cleaners will evaporate due to their alcohol base.
Whoa what real nice feeling to here the ole girl bark like that...sprayed some fuel in carb and ran a bit.
Thanx Dave
DAVE
From Ontario...That's in Canada not in California eh !
From Ontario...That's in Canada not in California eh !
1975 JD 400 backfiring ?
Ya know Ive cleaned many many sets of points and although its so simple sometimes you get the weird problems like this that make you pull your hair out. I have as a personal record 7 times yes 7 trys cleaning a single point on a 292 kawi motor before it finally worked. But there is always that great sense of satisfaction when you make something old run again.