X8 still broke

400brian · Post by **400brian** » Sun Jan 21, 2007 5:26 pm

Paul called just before I got in the house this afternoon, so I didn't get to talk to him.

I'm guessing he wasn't calling to tell me how swell the X8 was running. He was leaving for work. Spoke to his wife, she told me the X8 wouldn't start this morning.

Oh yeah, one of the kids broke the throttle lever off the Kitty as well this morning!
So he was kinda bummed she said.

Nothing worth having comes easy.

Danzig · Post by **Danzig** » Sun Jan 21, 2007 5:36 pm

Still bad. But better.

Ran it today after picking it up from the shop last night. Made it farther on the ride than I have been. But after it gets good and warmed up, right back to full choke.

This is what I am planning to do now. I have the WDA-34 with me at work today. I am going to break this carb back down to pieces. I want to use the WDA-34 throttle assembly with the choke setup and use the gaskets and reeds inside it also, but use the jetting and fuel pump plates etc from the WRA-31. Where am I going to run into troubles. Something is different I am sure but I dont recall. Anyone answer this and give me some directions?

Then got the cat out, fired right up, took her for a spin. Sweet. Stop back by the house, get the youngest daughter who is 8 years old. We go bopping around town and then head up to the park. I decide lets her run the throttle and and I will help her steer. She does excellent. So after about 20 laps around the park, she is doing well. I then decide I will let her go solo, she does excellent but needs to chill out on the jack rabbit starts. Finally after another 20 laps with her solo she is cold and ready to head home. I jump on and we take off, now comes the issue. I have to give the cat full throttle to get it out of the park. She broke it.......just kidding. We make it home pull out the plugs, PTO side plug soaked, Mag side nice and brown. Uh-oh, call the cat racer buddy of mine, fill him in. Recommends taking off the bowl on the PTO side carb and check the main jet for being loose, it was a little loose. Call him back due this not being the fix. Keep looking and guess what, I find the problem, the dang throttle cable broke inside the housing leading to the PTO side carb, the slide was not opening up. Look up the Cat in Dennis Kirk's mag, they dont carry my application, call them anyhow only to my dismay, still dont carry one. Look up Central Snowmobiles catalog, we are in business. Thank god.

I may have to run to the Deere Dealer and put the leaping Deere emblems on the Cat in order to ride with you guys at the HOF. I sure hope not.

Needing some carb info guys!!

Danzig · Post by **Danzig** » Sun Jan 21, 2007 6:50 pm

The WDA-34 is torn down and soaking in acid again, I think I may have found its problem too.

Maybe or maybe not.

I am thinking I have a extra membrane piece that is not needed when I rebuilt this carb after I rebuilt it last year. I compared the pics of the WRA-31 that I took yesterday and I do not see the membrane used in it like I have in the WDA-34.

Gonna compare the pics and the layout of the gaskets, reeds and membranes. Hopefully I could go back to this carb if this is the case.

Danzig · Post by **Danzig** » Sun Jan 21, 2007 7:14 pm

Something is not right for sure.

If you look back at the internal carb pics I posted yesterday (second pic) which are of the WRA-31, the top right part in the pic is the very thin rubber gasket/reed, this goes on top of the 3 springs.

In the WDA-34 which I am currently working on I also have this same thin rubber gasket/reed which goes on top of the 3 springs, plus I also have one of those brown looking membranes then being installed on top of that which this piece is much thicker and I feel is causing the springs to bind up and not allowing the little flappers or reeds to move. The WRA-31 does not have this piece that I can recall and all the pieces are in the pic for that particular area. Am I onto to something here guys?

Danzig · Post by **Danzig** » Sun Jan 21, 2007 9:38 pm

This is what I left out of the WDA-34, I didnt see this in the WRA-31.

Danzig · Post by **Danzig** » Sun Jan 21, 2007 9:59 pm

Rich-
What would you call the piece in the last pic?

Gasket, diaphragm, ??

Rodimus Prime · Post by **Rodimus Prime** » Sun Jan 21, 2007 10:19 pm

its the reed valve for the plate that has the three tiny springs.

Danzig · Post by **Danzig** » Sun Jan 21, 2007 10:24 pm

Rod-
I do have another piece that is over the 3 springs already and that is a very thin membrane of rubber type material and then around that entire plate there is a thick gasket. The piece in the pic, does it need to be in there? Like I said before, the I do not recall seeing this on the WRA-31 and I dont have it in any of the pics from yesterday either.

Danzig · Post by **Danzig** » Sun Jan 21, 2007 11:13 pm

I have to take your word then Rich, you dont call for a reed valve in that area. If this is the case, I am ready to give this WDA-34 another go.

Danzig · Post by **Danzig** » Sun Jan 21, 2007 11:50 pm

Got ya on the plug, the screen is gone, but all is clean. The WDA-34 carb is so clean on the inside you could brush your teeth in it. Torch cleaning tips were used where applicable too.

So far it sounds as if we are on to something here on this carb and its kit.

Rodimus Prime · Post by **Rodimus Prime** » Mon Jan 22, 2007 2:09 am

i do know that some kits contain both a hard and soft reed valve (tilliston ) for slightly different models..

it is also possible that you need both the rubber and the hard part for reed.. its been awhile since i last did a walbro. and i don t have an untouched original in house at moment.

the only thing i do ask is if under circuit plate (little plate with three screws ) that you have both gaskets and rubber reed valve aligned there is a pin hole all the way through. if you only put one gasket and the rubber reed you would encounter problems. there is also two measurments that must be done on inlet needle as seat.. one under arm and one with base of carb.

400brian · Post by **400brian** » Mon Jan 22, 2007 4:43 am

Paul
The brown "thing" that you are concerned about is "extra" for this application as far as I know. I left it out of the carb I rebuilt last spring. Rich is looking at the same pictures I am looking at, he has it right as far as I can tell.

Will be opening up my WRA-31 in the next few days.

Danzig · Post by **Danzig** » Mon Jan 22, 2007 3:58 pm

The WDA-34 was installed today leaving out the harder brown reed unit, built exactly as how Rich put it. No good. Sled runs, but same as it always has done, gets running and then will start to die, give it full choke or place your hand over the carb throat and she will catch up again and so on.

I now left the sled torn down. Both carbs are in a box waiting to be taken to work tonight and disassembled side by side. I am starting to think this may not be a carb problem at all anymore, I just dont know.

I also removed the intake and the 2 reed assemblies and cleaned all of it in parts cleaner. The reeds are closed and not stuck open and look to me like brand new.

I also looked for another impulse line connecter on the other cylinder and there is a screwed in plug, should I try pulling off this cylinder rather than the one it pulling off now?. After looking inside the engine after the reeds were removed it looks very clean and nothing appears to be out of the norm, but I dont exactly know what to look for either. The reeds have been installed and intake put back on.

Still broke.

400brian · Post by **400brian** » Mon Jan 22, 2007 5:28 pm

I'm not aware of any reason you couldn't try the other side of the case to run the pulse line. In fact it is something I had considered sugesting. Inspect the pulse line and both fittings, could anything be cracked and leaking?

If you have the carbs rebuilt correctly, and the problem persists, we'll have to re-think the situation. You have to eliminate the most likely possibilities one by one, and your description sure sounds like a fuel issue.

Not trying to confuse things further, but there could be other issues: ( it does seem like a long shot at this point )
Back in the day, I had a coil go bad on the 400. It would start and idle great, and the spark looked good on the removed plugs, but it wouldn't make power. You say yours will rev up if you load it up by choking it, that is why I have tended to think you were on the right track, it sounds like a fuel issue.

If you remember, back when you bought the new carb I mentioned I wasn't sure that the carb was the problem. However, remove the posibility of it being a fuel problem, before looking at something else.

I'll keep thinking about this.

Danzig · Post by **Danzig** » Mon Jan 22, 2007 7:41 pm

The sled runs as if it has a vacuum leak, like on a car and you have to put your hand over the carb to keep it running.

Like I said, the engine was pressure tested and it held 8psi forever.