RX1 losing throttle response and back firing

[rx1rle]

Just got back from a200km run today but had trouble all day with the sled. Everything is running along fine and I get completely off the throttle to turn at an intersection and when I go to hit it again nothing, no throttle response at all. Had to wait until the engine idled down and then it work fine again. This happened all day when ever I got out of the throttle. Very dangerous trying to get out of a turn and someone is behind you.

Tried some gas line antifreeze thinking it was moisture but no change. Wish full thinking, no luck.

It is really acting like the choke is stuck on a little. I checked it and it looked fine. i.e. the linkage between the carbs was returning back to the in position when I operated the choke switch.

Oh, I forgot to mention also that it is back firing real bad at the same time. Not always but most of the time. It didn't start back firing until later in the day so it could be a result of a fouled plug as a result of.

It's a 2004 RX1.

Has anyone ever run into this? Any ideas?

Thanks

 

[SnoWarrior]

TORS

When you turn your throttle cable is binding or is too short. Do you have risers on the sled?

Throttle override system (T.O.R.S.)
If the carburetor or throttle cable should malfunction during
operation, the T.O.R.S. will operate when the throttle
lever is released.
The T.O.R.S. is designed to interrupt the ignition and
keep the engine speed between 2,800 and 3,000 r/min if
the carburetor fails to return to idle when the lever is
released.
WARNING
@

If the T.O.R.S. is activated, make sure that the
cause of the malfunction has been corrected and
that the engine can be operated without a problem
before restarting the engine.

Be sure to use the specified spark plug and spark
plug cap. Otherwise, the T.O.R.S. will not work
properly.

To adjust you have to loosen the 10MM nut on the throttle cable where it connects to the carbs. Then turn the cable adjuster so there is a small gap on the flipper where it rests.

 

[rxwarrior]

Also, check that your airbox is still mounted all the way onto your carbs.

 

[apltx08]

Pull your spark plug coils out and clean them up with break cleaner and use some DIELECTIC grease on the plug and rubber boot to keep them from arcing...

 

[Len Todd]

All excellent suggestions. Did they clear up your problem?

 

[rx1rle]

Air box is connected ok.

Couple of the spark plugs were dirty/burnt. Cleaned and added dielectric grease.

TPS tested ok.

Coils tested ok.

The carburetor switch (TORS) on the other hand doesn't seem to be working. I tested as per the manual page 8-8 and it has no continuity at all (whether the throttle is operated or not).

The sled has no risers and the cable seems fine with 2-3mm of free play.

As anyone ever ran into this? Do you think it's faulty? According to the book it appears to be.

Is it really necessary to have this working? It appears to be some sort of safety but it can be bypassed.

 

[Nate01]

try to by-pass it and if it fixes your problem then you know where to start looking...just the 2 connectors (4 wires) above the carbs....just un-plug and plug into each other....only goes one way...

 

[Len Todd]

You can bypass TORS for testing. But when done testing, you need to hook it back up. It is a safety device to compensate for frozen throttle cable.

To bypass TORS, disconnect the two wires running to carbs near delta frame by the carbs, then plug the two wires coming from the sled into each other.

 

[edge_kw]

I had pretty much the same issue as you described.....backfire and total bog after letting off heavy throttle (for corners, etc.) only mine was very intermittent. This was last year.
Early season, I bought (4) new coils. After receiving coils, but not installing, I took the sled for one ride and didn't experience the problem at all (like I said "intermittent"). Haven't ridden since (torn AC ligament in shoulder) but I think bottom line, the hesitation or stumble you're experiencing is going to be the coils as well.
btw - mine is an '04 Warrior.

 

[kinger]

Did you check it in a dark room to see if the coils are arcing against the engine?

How many miles on the sled? Exhaust donguts usually cause a back fire but seems like you have enough other stuff going on its probably caused by that.

 

[rx1rle]

Well, it's official, the TORS is operating as it should.

The carburetor switch has to be faulty.

Bypassed it and the sled works great.

So, as anyone changed a carburetor switch? Can you just buy the switch, which looks like it would be a pain to change, or does it come as an assembly with the throttle adjuster and all?

 

[Len Todd]

Yes you can buy the switch separately. It is Item # 47 on the attached figure.

 

[DaJudge]

Before you go out and buy a new switch, I would try adjusting the TORS to make sure it is not just out of adjustment. You could replace the switch and still have the same problem if it is just an adjustment problem. You also want to check the thumb throttle lever also. There may be a piece of ice or something in there. There is 2 switches involved in the TORS, one on the carbs and one on the thumb throttle. They are designed to work together. If one doesnt work the other wont either.

 

[rx1rle]

I know the thumb throttle lever switch works as it should and reduces engine rpm to 3000.

The only way I know to adjust the carburetor switch is to adjust the throttle free play which it on spec at 2-3mm.

Is there any other adjustment I could make?

Thanks

 

[DaJudge]

Try putting more free play in the throttle cable. Not a lot just a little more.