Snowmobile Fanatics banner

1 - 16 of 16 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #1
Hello all, After buying myself a new sled (xc800sp love it!) I gave my wife my yr2000 triumph as her first sled. It runs great when starting it cold and runs great for hours, but it seems that restarting it after say lunch or .5 hr to 1.5hr it will idle fine but backfires at midrange throttle, also seems to have a loss of power, I have changed out plugs which has not helped, and have checked spark on the three cylinders while it is acting up but they all seem to be firing. Any ideas, or suggestions anyone? Thanks for any help in this matter.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #3
I do not recall noticing whether they were wet or not I will check the next time this happens. I have tried the new plugs which has not helped and checked for spark, which is there.
 

·
Registered
Joined
·
5,686 Posts
Welcome to the forum Rich. You will find it helpful.
Is the jetting and needle clip position stock?
 

·
Registered
Joined
·
14 Posts
Discussion Starter #5
Thank you ACEXLT, I bought the sled used and the previous owner did say he had the jets changed to try to improve fuel economy thats all I really know, except it didn't really help the mileage much.
 

·
Registered
Joined
·
5,686 Posts
Pull the carb rack and see whats in there for mains.Also read this thread.......

http://www.snowmobilefanatics.com/snofan/topic.asp?TOPIC_ID=4310
 

·
Registered
Joined
·
14 Posts
Discussion Starter #7
ACEXLT I am new to the mechanical side of the carbs is there any online literature available, or is it something you can explain to me? I looked at the article you recomended to me, it sounds like an easy procedure, but I am unsure of how to know the jet size by looking at them, and which screw is the correct mixture needle. I am going to tear into it tonight after work and will keep you posted, thanks again for the advice!
 

·
Registered
Joined
·
23 Posts
Hey there Rich, check out some of my responses on " 2000 XC 600 Deluxe backfires in the Midrange " and see if any of those suggestions help you. Good luck!
 

·
Registered
Joined
·
2,729 Posts
Sounds like ACEXLT has got you in the right direction. I'm a little slow responding due to riding all weekend. But what you need to do is to change the c-clip position on the mixture needle. I personally run my Triumph with 350 main jets, e-clip in number 2 position and air screws turned 1 and 1/4 turns out. My sled runs flawlessly unless i get careless with the choke.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #11
Thanks Triumphoveru so far I have reset the c-clip position from #4 to #3 position. I have also changed out the plugs which were black and wet. I will check the air screws today and try it out.
 

·
Registered
Joined
·
133 Posts
Ok Now I've got a Q for ace. Did you go 340 + #3 pos. or 350 + #2 pos.?
Do think or know how close a 99 XLT SP is to a Triumph. My B-in-law and his wife have these sleds and they seem identical in the engine compartment. Always changing plugs, run like shit la de da. I have the XLT in my garage right now with the rack off it cause my b-in-law wants me to take a look at it. Both of these sleds are as they came from the dealer. My Indy trail and edge x were helped a bunch by swapping out some as shipped stuff.
 

·
Registered
Joined
·
133 Posts
And just out of curiosity, does your PTO carb throttle plate match the other two? On this one the PTO slide is cut away on the back side.
 

·
Registered
Joined
·
5,686 Posts
The only major difference between the '99 Xlt and the Triumph is the chassis (Xlt= agressive/Triumph= GenII and re-badged). I am running the 340's and clip in #3 position(did not touch idle air mix screw-stock is 1.5 turns out) with good results. That is one move down on the jetting chart in the factory service manual. These were jetted too rich from the factory. On the throttle plate,thats a good question and I did not notice that.You have me curious on that, but not enough to take it apart again.

I'd almost bet that jetting down that 1 step would solve the problem with all those sleds.also check choke lever freeplay,should be 1/8" to 1/4"
 

·
Registered
Joined
·
14 Posts
Discussion Starter #15
--------------------------------------------------------------------------------
Well I finally was able to get out and try the sled. We went up into northern Maine to the wide open trails and it just ran great all day. All I have done to it was reset the needles from #4 to #3 position we put on 160 miles during the course of the day, I did shut off the fuel during lunch, it never backfired or even hesitated all day long. At the end of the day I checked the plugs which were tan on the very end but were a little dark & wet around the threads, definetly a big improvement all ready. Next time we go I'm not going to shut off the fuel during lunch to see if thats when it gets overloaded with fuel. I am thinking of moving the needle clips to #2 position to see if it might further help the plugs. Will let all know, Later
 

·
Registered
Joined
·
370 Posts
I have changed needles. Now I only get backfires when going slow. So the easiesy fix is don't let the wife drive it.
Also it made a big diference in my gas mileage. I go riding with 600 twins there on empty and I got 1/2 tank.
 
1 - 16 of 16 Posts
Top