JDX 8

Deleted User · Post by **Deleted User** » Fri Jan 18, 2008 12:34 am

I have a 73 (i think serial # 005588m) jdx 8 that keeps fouling the mag side plug. both plugs bright blue (with a touch of white in the center) spark, compresion is 140 in each cylinder. I am running NGK B7HS plugs and a 20:1 mix. when the plug fouls out i switch them around and it runs good for a while again. I looked at the reeds and they appear to be good. My question is what could be causing just the mag side to foul out and would it be ok to switch to 50:1 mix

bill

Danzig · Post by **Danzig** » Fri Jan 18, 2008 12:45 am

Go to the 50:1.

440 invader · Post by **440 invader** » Fri Jan 18, 2008 2:19 am

I run 50:1 in my '74 X6 with no overheating or fouling.

JDT · Post by **JDT** » Fri Jan 18, 2008 2:28 am

Before this thread turns into a oil ratio debate remember that ony one plug is fouling out.
If 20:1 was the problem they both would go bad.

Here is a thought... could it be that you are running too rich and the reason that the pto side does not foul is due to an air leak?

When you checked the reeds did you look at both sides?

Todd

Danzig · Post by **Danzig** » Fri Jan 18, 2008 2:36 am

Yeah your right Todd. This will not doubt end up in a oil ration debate rather than finding the root cause of the problem.

400brian · Post by **400brian** » Fri Jan 18, 2008 5:08 am

What color are the plugs? Black, brown, tan?

400brian · Post by **400brian** » Fri Jan 18, 2008 4:40 pm

Rich

Just wondering; do you know the date when those reccomendations were made?

Deleted User · Post by **Deleted User** » Fri Jan 18, 2008 10:32 pm

the plugs are tan with a touch of black
I know i am mixing rich but that's what my manual recomends.
i checked the reeds on both sides and they seem ok to me, the're not tightly closed but with slight pressure they are.
How do i check for air leaks?
when idling it seems a little rich. acceleration is ok (a bit slow at first)
at wot it seems a bit doggy, seems to miss a little and doesn't really hit top end.
I tried ajusting the carb up and down at wot and this didn't seem to matter.

400brian · Post by **400brian** » Sat Jan 19, 2008 2:27 am

What have you done to it?

Have you went through the carb, gas tank, filter, pickup and fuel lines?

Fuel issues are probably the number one thing.

Deleted User · Post by **Deleted User** » Sat Jan 19, 2008 12:44 pm

the carb thats on it now is a WDA-31 and it always ran really good.
I will check the carb over and try it one more time and if it still doesn't work then i will look for a WRA-31. This is my sons sled and i have to get it running so he stays off my spitfire

Thanks for all your help guys.

bill

Deleted User · Post by **Deleted User** » Mon Jan 21, 2008 1:03 am

OK i found a few problems with the carb and got them all taken care of, put new plugs in and it was running in 3 pulls and was idling good then when i gave it some throttle the mag side started to miss. So i took the rubber cap off the plug wire set the wire on the plug, started it up again and held the wire a little above the plug and found that the spark is intermittent. What could be causing this? i was thinking a coil but i have never had one act like this before. condenser maybe? I am going to try new plug wires but i don't whant to buy a bunch of parts i don't need. I have never been very good with electrical so this has me stumped once again

:unsure: . any ideas would be great.

Bill

JDT · Post by **JDT** » Mon Jan 21, 2008 1:21 am

Check out this short list.
Points... clean and check gap
Plug wire... check were it screws into the coil, cracks in wire, test wire with ohm meter
Coil... check connector at red or white wire, rust expanding plates on coil
See what you find here and then you can go further.

Todd

400brian · Post by **400brian** » Mon Jan 21, 2008 3:25 am

A new set of wires and plug caps might be in order, if for no other reason as to eliminate them as the problem.

At the very least, cut a 1/4 inch off each end of the wire, and rescrew it into the coil and plug cap.

Dirty/corroded points are a very good possibility.