Thanks DE, you make it sound so easy! Do I need any special tools to get the clutch or flywheel off of the shaft? I just ordered the whole Walbro pump rebuild kit along with the 73-75 JD 400 seal kit from newbreedparts... I had taken the four screws out of the bottom to take a look inside and now th...

Thanks again for the help guys. I will try flipping the butterfly around first and then go from there. I had checked the crank seals the last time that I had the sled running (about a week before this happened) by spraying a bit of ether around them to see if the RPMs would go up and there was no ch...

Well I tried to search past topics to see if anyone else has had this problem but I couldn't find an answer, so here goes... My '73 400 would sometimes stall while idling because the linkage that the throttle cable attaches to was loose on the throttle shaft and would slip behind the idle screw, all...

Thanks again everyone. This site is incredibly helpful.
I'll order the right seals (hopefully) and see what I can figure out.
We just got a nice layer of snow this morning, too bad I've got a few things to fix first.

Thanks for the help so far guys. So I went to newbreedparts.com and found the "Winderosa Gasket & Seal Set for 72-75 400, JDX4 Special." Here's the link: http://www.newbreedparts.com/index.php?route=product/product&path=59_65&product_id=73 It looks to me like this is the right ...

I just picked up a '73 400 (my first snowmobile actually) which had been sitting since the spring of '09. I've heard that the crankshaft seals can fail, which leads to disaster. My question is (and I probably should know this but I want to make sure): when the seals fail, how can you tell? Will fuel...