'74 400 runs for 5 seconds and dies.

cpolaris502 · Post by **cpolaris502** » Sat Jan 14, 2012 6:21 pm

I bought this snowmobile a few months ago with the carburetor in a box in pieces. it has a walbro WDA-1 on it which I understand is not the right carb in the first place for it. I ordered a rebuild kit for it and reassembled it minus the 3 valve springs (they were missing and didn't come in the kit and have now been on order for over a month) and through it on the sled. the first time I was messing with it, it was just dumping fuel in. So much that it was dripping out of the intake of the carb. I then pulled it back apart and checked out the metering lever which I think was misadjusted and staying open. I bent it to what I think is suppoosed to be right now and it stopped spitting fuel out of the intake if I remember right, it was months ago.

Fast forward to today: I decided to take some clicky ink pens apart and try to use some springs out of those. I cut them to the length I *think* theey should be and put them in. It didn't really change anything. I've had them in/out, adjusted the needles to closed, 1 turn out, 1.5 turns out and everything else. It will not run on it's own! The only way it runs is when I use the primer.

Taking the carb apart after it ran for a few seconds, it looks like fuel is getting through the metering needle but it's hard to tell. it could just be wet from gas leaking as I take it apart.

What are the 3 valve springs supposed to do in this carb? Why does it only run for a few seconds, clearly it runs out of fuel, but why? this thing has been so frustrating. I have super strong spark, high compression (I think it was 130psi+). Any help please?

And lastly what are the differences between the wda series carbs. This one should have a WDA-32 on it according to the service manual.

Liquifire84 · Post by **Liquifire84** » Sat Jan 14, 2012 6:40 pm

I had this same problem back in the 80's. It still haunts me to this day. I changed out the carb lastly to a WF and it ended. The passages in the old WDA were partially closed and caused me lost sleep. I rebuilt it a number of times. The pump diaphram part of the stack was always giving me problems.

Brice

cpolaris502 · Post by **cpolaris502** » Sat Jan 14, 2012 7:27 pm

I'm starting to think my next thing will be to buy another carb and junk this one, unless I can get some good advice in here. i just don't get it.

Post by **Matt** » Sun Jan 15, 2012 9:01 am

Like Brice said, the Walbros have a lot of tiny passages, make sure they are all open. There is also a small screen in one of the fuel pump plates, take another look at it. Has the sled EVER run on the WDA-1? There is the possibility that the carb just isn't set up right for that sled, and it was a previous owners attempt to replace another problematic carb with an incorrect one.

cpolaris502 · Post by **cpolaris502** » Sun Jan 15, 2012 6:52 pm

Update: I had a friend over today who knows a lot about John Deeres. We got it running on choke, but it will not run off choke. it's like it needs the vacuum to be able to pull fuel through the carb. With the fuel return line removed from the carburetor, it was not spitting gas out of the return until the choke was closed. So now it will not run off of choke. We played with the needles a lot and sometimes got it in the ball park, but never good enough to run like it should.

cpolaris502 · Post by **cpolaris502** » Sat Jan 21, 2012 10:19 am

I picked up a WDA-37 which made it run a litle better, but still only on choke. I am now in the process of replacing all of the gaskets and seals in the motor. It has to be sucking in air somewhere. I replaced the Mag side crank seal and it did now help, I did this because the spark plug was tanner on this side. I will update again when I find some new info on what's going on.

JDT · Post by **JDT** » Sat Jan 21, 2012 10:57 am

In my experience it is usually the PTO side that fails but always replace both. Always!

o man · Post by **o man** » Mon Jan 23, 2012 12:07 am

MINE WAS THE HOSE FROM THE CRANK TO THE PUMP OR THE OTHER THING IS CRANK SEAL

cpolaris502 · Post by **cpolaris502** » Wed Jan 25, 2012 10:00 pm

Well... i just put the motor back in it tonight after all new seals and gaskets, brand new pistons and rings too. NO CHANGE in the way it runs.

So now I am sure that the carburetor is not working the way it should. it only runs on choke, I have played with the needle settings all over the place. So it seems that the pump is not working the way or it should, or else the WDA-37 will not work on this thing. One or the other. What do you guys think?

So my next goal is trying to get this carburetor troubleshooted or just look for a new one all together. Any ideas on what other carbs I could look for? I might make it to waconia this weekend and could try looking there.

JD600 · Post by **JD600** » Wed Jan 25, 2012 10:46 pm

PM Sent.

DE

Red · Post by **Red** » Sun Jan 29, 2012 9:13 pm

If you need it, I have a pretty nice WDA-32 that is just sitting in a box in my basement. This should be the correct carb for your sled. The carb looks to be in very good shape but I haven't had it on a sled to test it. If you need it, PM me and we'll talk turkey.

Dennis

cpolaris502 · Post by **cpolaris502** » Mon Jan 30, 2012 10:15 am

I ended up finding a WDA32 this weekend down at Waconia for $5. To my surprise, when I opened it up, it had every part inside! Including the 3 tiny valve springs. I cleaned it up real good and just put it back together with all of the existing gaskets, put it on the sled and it fired right up. I was pretty amazed, turned the choke off and it kept running.

There's still some things to figure out with it but it ran way better than it ever has before. It will idle for a minute and then just suddenly die, and it is real unresponsive right off of idle and at midrange. When restarting it, I need to prime it again so it's like it runs itself out of fuel. I played with the metering lever height just a little bit and it kind of helped. But taking it around the yard for a few laps sure felt good. Hopefully I can get it dialed in just the way it should.

cpolaris502 · Post by **cpolaris502** » Tue Jan 31, 2012 10:11 am

Update: think I got this thing figured out now. I pulled it apart and swapped metering lever springs last night since the one I was using was tweaked a little. That fixed the idle and low rpm operation. I had it running perfect... And then I lost spark in the mag cylinder. Ugh, it's always something. Luckily I have dealt with this before when I first got the sled. Something in the points/condensers again. Both were brand new 2 months ago.

JD600 · Post by **JD600** » Tue Jan 31, 2012 10:31 am

You might try switching the red and white wires coming out of the stator and check for spark again. If the problem changes sides, its under the flywheel. If the problem stays on the same side, you have a bad coil, plug, or plug wire.

hope this helps.

DE

cpolaris502 · Post by **cpolaris502** » Tue Jan 31, 2012 2:38 pm

Yup, that's how I determined its down there again. I just wonder why I'd have a problem with them right away again.

'74 400 runs for 5 seconds and dies.

'74 400 runs for 5 seconds and dies.

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Re: '74 400 runs for 5 seconds and dies.

Re: '74 400 runs for 5 seconds and dies.

Re: '74 400 runs for 5 seconds and dies.

Re: '74 400 runs for 5 seconds and dies.

Re: '74 400 runs for 5 seconds and dies.

Re: '74 400 runs for 5 seconds and dies.

Re: '74 400 runs for 5 seconds and dies.

Re: '74 400 runs for 5 seconds and dies.

Re: '74 400 runs for 5 seconds and dies.

Re: '74 400 runs for 5 seconds and dies.

Re: '74 400 runs for 5 seconds and dies.

Re: '74 400 runs for 5 seconds and dies.

Re: '74 400 runs for 5 seconds and dies.