X8 still broke

Danzig · Post by **Danzig** » Tue Jan 16, 2007 3:56 pm

Took her it for a little ride today on the 2 inches we have. Sled will run with choke off and idle fine, go to give her gas, she falls flat on her nose. Before it dies off, I quickly pull the choke on and she gains power again. Not really sure what is going on, this weekend I am going to do the pressure testing of the engine. Also, the carb is the WDA-21 as suggested. The Cat is defintely now coming with to the HOF.

This is getting old.

Danzig · Post by **Danzig** » Tue Jan 16, 2007 4:05 pm

1.5 turns counteclockwise or open. Low side is the same also. This thing ran great when the weather was in the 45 degree area. Idles beautifully at 2200 rpms.

400brian · Post by **400brian** » Tue Jan 16, 2007 9:33 pm

Sounds like it is not getting fuel, but you've been fighting this a long time, check the motor out, then you'll have an idea where you stand.

Is it doing exactly the same thing as before you changed carbs?

Danzig · Post by **Danzig** » Tue Jan 16, 2007 10:31 pm

The performance is much better with this carb, it pulls hard. Alot more power, less bog, till now or 50 yards of riding. Yes, it is acting just like it did the last time we had snow. I am thinking a crank seal may be failing under a higher RPM. Due to that it will idle great, but get the RPM's up over a 50 yard ride and she then falters, it will die if I do not quickly grab and pull the choke full on. I have done the carb cleaner trick, done the starting fluid trick, replaced the PTO crank seal last fall also. But I could also have a main jet or high idle jet plugged too. Today, another new set of B9ES's were also installed and extras bought to take along to the HOF event. I also pulled these new plugs out after I had ran it and they are the cardboard brown color. Is this the proper plug? I have spare Champions and the length of the threads are shorter than what I had found to be in the glove box when I first got this sled. The last carb or original which was a WDA-34 would not idle at all, the idle was up and down nothing consistent.

Motor is a 1973 KEC440/21.

Another thing, this is supposed to be a reed valve engine. I do not see reeds when the carb is off looking down the intake, I am not sure what I am looking for either.

I do not think timing would be a problem either, I do not here detonation or pinging at all, and it does start easy.

Spark is bluish/white.

Running 89 octane BP fuel with Castrol 2 cycle snowmobile oil. 50:1 mix.

JDXspec · Post by **JDXspec** » Tue Jan 16, 2007 10:50 pm

Check the fuel Filter and the pickup line in the tank. Its getting fuel but not enough to run high RPMs I would say you will find an obstruction in the pickup inside the tank. My 74 JDX8 did that, was crap plugging the line in the tank.

400brian · Post by **400brian** » Wed Jan 17, 2007 3:56 am

Paul

Not that it has anything to do with your current problem, but I think you are running the wrong plugs. I'm quite sure you should be running the short reach plugs.
The NGK charts I have seen don't list 440/21, but my '73 X8 has the short reach plugs, like the '72s did. I think you need B9HS or B8HS plugs, or go back to the Champs.
Wow, I'm suprised you're not making contact with the tops of the pistons!

:o

Your 440/21 is a reed. Your carb mounts on the crankcase does it not? The piston ported engines have a intake manifold runner leading to the side of each jug.

I know you've been all through this stuff, but what does your tank look like? What does the pickup screen look like? I know you didn't open up the new carb, what's in there?

kwc · Post by **kwc** » Wed Jan 17, 2007 9:56 am

Paul - what is the WDA-21 carb from? I was looking in my service manual and I don't see that one listed.

kwc · Post by **kwc** » Wed Jan 17, 2007 10:22 am

That makes sense.....didn't mean to jump in late on this one.

grasscutter97 · Post by **grasscutter97** » Wed Jan 17, 2007 12:24 pm

Long shot...but your description is exactly what I had on an old Trailfire. Found head gaskets were shot (heads from a previous owners 'rebuild' did not get torqued correctly). New OEM gaskets, and she's off and running. May not be your prob, but it worked for me.

<<<<<<<<<<The performance is much better with this carb, it pulls hard. Alot more power, less bog, till now or 50 yards of riding. Yes, it is acting just like it did the last time we had snow. I am thinking a crank seal may be failing under a higher RPM. Due to that it will idle great, but get the RPM's up over a 50 yard ride and she then falters, it will die if I do not quickly grab and pull the choke full on. I have done the carb cleaner trick, done the starting fluid trick, replaced the PTO crank seal last fall also. But I could also have a main jet or high idle jet plugged too. Today, another new set of B9ES's were also installed and extras bought to take along to the HOF event. I also pulled these new plugs out after I had ran it and they are the cardboard brown color. Is this the proper plug? I have spare Champions and the length of the threads are shorter than what I had found to be in the glove box when I first got this sled. The last carb or original which was a WDA-34 would not idle at all, the idle was up and down nothing consistent.>>>>>>>>>>>

Danzig · Post by **Danzig** » Wed Jan 17, 2007 1:33 pm

I want to add this too. The exhaust ball and socket joint when I first started it yesterday was very wet with oil, after taking it out on the ride that I attempted to do which was about 100 yards, this ball and socket are clean, oil free totally. Its obvious that I went real lean.

I heading out right now in the 15 degree weather and take a look at the fuel tank line pickup screen. The fuel filter is a clear inline type and it looks very, very clean.

Brian, this carb bolts on to an intake, the intake has a port that leads to each cylinder. The intake is held on with 8 studs and nuts. 4 studs on top and 4 on the bottom of the intake.

The plugs that I have found in the glove box a year ago are Champion L82C.

Danzig · Post by **Danzig** » Wed Jan 17, 2007 1:52 pm

15 minutes later.

Pulled the fuel tank fitting out of the tank and the pickup screen anti-fuel return valve is clean. Nothing on it restricting flow. Fuel filter again clear inline, clean.

I started her up and she runs great, getting plenty of fuel, got the oil/fuel dripping from the ball and socket exhaust union again. I didnt ride it, shes back on the trailer. I did rev her up till the drive line hooked up, it didnt falter. Still not fixed by no means.

Looked further more into the treasures that came with this sled and also found the L78 old plugs also. I am going to call the local store now and get a cross reference from champion to NGK.

Danzig · Post by **Danzig** » Wed Jan 17, 2007 2:01 pm

L78C Champion plugs cross over to NGK B7HS.

I have been using the B9ES and have also used the BR9ES.

:o

:o

:o :

Heading out the door right now to go get these plugs. The store has 3 of these, not no more.

Danzig · Post by **Danzig** » Wed Jan 17, 2007 3:07 pm

Correct NGK plugs are in, still have the same problem. B7HS NGK

Unloaded it off the trailer and she fired right up, got about 25 yards and it acted up again, pulled the choke full on to keep her running, let idle catch back up till the point the motor acts like its loading up with fuel, push choke back in and take off hanging on for dear life and then another bogged down event. I guess the next thing to do is get her inside and do the engine pressure test and then if that checkes out good then take the carb off and check it for crap inside. Agree?

I also looked at the fuel lines and I do see fuel consistently flowing to the carb, there are bubbles present in the line feeding the carb. I have good fuel return also.

JDXspec · Post by **JDXspec** » Wed Jan 17, 2007 3:12 pm

I would go B8HS thats what i run. B7s may be too hot. Could it be that your ck valve is sticking in the tank? good way to ck, put a primer bulb (like a boat primer) in the line. Then run it like you normally would and when it falters , quick ck the primer, if it is deflated theres a restriction. When idling it would probably inflate again.

Danzig · Post by **Danzig** » Wed Jan 17, 2007 3:28 pm

Dustin,
Thanks for the advice, got a better idea than that. I will simply remove the check valve all together and try it.

Still open for more ideas guys.