I had my 84 ET300 running perfect last time I used it. I got it out this fall and it will not run right. It kills a plug almost instantly. Back fires out of the carb. I took the carb off again and looked at it. Cleaned it again. Although it seems perfectly clean. I'm at a loss. Any advice?
I have a 1989 Arctic Cat Cougar 500 fc, dual carbs, one cylinder heats up more then the other at idle and bogs when you open the throttle to fast idle at 15000 rpm is impossible unless i put my finger in the carb just before the slide, goes form 11000rpm to 1500 and idles fine without misfire. If my finger isnt there, it idles low and when you try to adjust the idle screw a bit, it revs up to 25000rpm and seems to run fine and has all its power but below that it bogs, i cleaned the carbs, motor was rebuilt, new crank seals, not to sure whats going on with it, cant figure it out.
Hey Mr Wolf, Sorry for the tardy response! Your problem sounds weird. I guess its back to basics, I'd run a stiff wire thru both pilot jets (or change them outright). Adjust the idle air mixture screws to the same setting (like 1 to 2 turns out from lightly seated). I'd also make sure the carb slides are synced exactly and the idle screws are set exactly the same. If you still get an un-even idle you may consider swapping the carbs from side to side to see if the problem follows the carb. Hows the spark on both cylinders, how is the compression? Be vary of air leaks in the carb flanges. I've had three 500 Suzuki Fan engines thru the shop over the years with broken or bent PTO output stubs on the crank (maybe its a weak spot?) Let me know how you make out, and good luck. Best regards Al Pinkney
Hi Rene, I didn't deal with studs issues on this sled as it wasn't mine. But first is make sure track tension is good, then install wear strips in the top inside of the tunnel. Finally possibly a set of smaller drive sprockets, but then chaincase gearing would need to be looked at to maintain a good ratio. Good luck!
Would it be feasible to replace that butterfly carb with a VM38 round slide carb? Seems like the Mv would be a bit less finnicky to work on, especially those tiny passages on the top of the bore. Just kind of speculating.
Yes I agree, the round slide would need a new throttle cable. I seem to remember the throttle lever didn't have enough travel to open the replacement carb though. Oh well it can be done for sure...
I just purchased a 1982 enticer 340 for my kids in the yard. It ran for the kids but when I jumped on it Boggs badly and smokes and won’t even moves sometimes. I pulled the carb and it was pretty clean but it’s really clean now. With it all back together I now have the idles screw and air screw all messed up. I had it started but it bogged then I messed around had it started and it ran full speed back to the yard and died as soon as I slowed down. What are the factory setting for the idle screw and air mixture screw?
wowI totally missed this message. I think the air mixture screw was initilly set at 1 turn out from seated . The Idle speed 😋screw? I guess its whatever suits without the sled running away on its own...
Hey there WFVS, I really enjoyed the video! It's the best video/info that Ive found on this carb! Im recently new to the snowmobile world and mechanics beyond theory haha Ive recently acquired a ET340 thats probably 79-81 and I'm just trying to get it back to working order and I was hoping I might be able to email some general questions. Thanks!
Good video Thanks. Cleaning mine. On the intake side in front of the butterfly there are 2 ports at 6 and 5 o'clock position. The one at 5 o'clock position has a brass jet that is clear. The one at 6 o'clock position seems closed and goes to nothing. I did not see you cleaning the one at 6 o'clock. Am I correct ? The port at 6 o'clock does nothing ?
Hmmm, Sorry I don't remember. I don't have access to that type of carb now. I do remember the top jets caused some mis-diagnosis, so I bet you will be ok as long as they are clear. Good luck and keep sledding....ALP
Hi Wesley, it could be a few different things. I'd try turning on the choke when it's bogging /dying. If the RPM's pickup it would seem like a fuel delivery problem. My email is wfvs@sasktel.net if you want to consult.
It's probably the "Throttle Restriction Override System". It's meant to prevent Stuck open throttles. I'd try adjusting the throttle cable slack, also make sure the throttle cable is not sticking...Good luck...
Wow, Thank you. I have an ET 300 and I've been fighting this carburetor for years. I held the butterfly open and sure enough two of the holes above were plugged up. Put the carb back on and it runs like it did when I bought it in 1980. I owe you a drink!!!!!!!!!!!!! John.
Hey that is great news mopardeer! I wish I could go back in time to a 485 Venture a fellow repair guy was struggling with.....in retrospect I'm sure it had the same carbs with the same issue....Oh well! Safe sledding!!
Hi Marit! Is the transporter the long track model? If so then the Yamaha PN is 8VO-85540-21-00. I think any ET340, or erven Phazer or Venture from those years would work on the Transporter. They seem to use the same CDI Box.. Good Luck!
I have a problem on my venture 480, its getting to much fuel, on full gas it just sounds like its getting to much fuel, but i cant find out whats wrong
@@HashiriyaDad Sorry about the delay in getting bck to you. yes i have had a few siezed choke cables and it's not fun. I assume you were able to screw the brass threaded fitting out of the carb body that holds the choke plunger in place. I would soak the plunger area in good penetrting oil and let it sit like overnight. Then pry upwards on the choke cable with a prybar of some sort (I made a forked tool to use). you mau have to buy a new a replacement cable. It should come out eventually. If all else fails one may have to install one of the primer kits and abandon the use of the choke, i'd say that is a last resort! Good luck and never give up...!
