Rx-1 at my wit's end! Carb issues??

[Sudbury451]

Hey guys, new to the site here. Have read every single post I can find online. Very mechanically inclined, very rarely that I can't figure out an issue. I have an RX1 that's new to the old man, hadn't been run in seven or eight years. Has 4,000 miles. Cannot get the sled to rev past 3500rpms unless I have the choke on. Starts great, idles great, no choke on won't spin the track just bogs and dies. Half choke - runs somewhat normal but has its surges and can hit 95mpg but throttle response isnt normal. Sled is bone stock

List of what I've done:

- new carb kit
- drained fuel, new filters
- carbs have been cleaned about 15 times. Totally dismantled, new jets, needle, o rings.
- carbs syncd
- checked for air leaks
- dismantled fuel pumps (haven't tested but looked fine - carbs are always full)
- tried air mixture at 2 turns and 2.5 no difference
- tried new coils - no difference
- new fuel, oil change,
- disconnected TORS, no change
- haven't checked TPS but read they were not designed to affect timing to the degree of this issue.
- sled has been warmed up enough before testing every time
- have tried new plugs
- compression is perfect
- jets are all in the right place
- I know about all the little o rings that can be lost. Nothing is missing


Have more than 40 hours taking these damn carbs on and off and it's the same thing every time. I have done hundreds of carbs and am ready to set this thing on fire.

Any ideas?

 

[RX-1MAN]

Well with everything you've done certainly sounds like carbs wouldn't be the issue. Been sitting 7-8 years, wonder if airbox or exhaust is clogged with something by Mice???

 

[Sudbury451]

Well with everything you've done certainly sounds like carbs wouldn't be the issue. Been sitting 7-8 years, wonder if airbox or exhaust is clogged with something by Mice???

Thanks for the reply! Airbox has been off so many times as well there can't be mice in there unless they managed to go through the drain or breather hose which wouldn't cause my issue. Both exhausts breathe nice when choke is on and I can increase RPM

 

[pdiddy]

What position is the e-clip on the needle jets?

 

[Sudbury451]

What position is the e-clip on the needle jets?

Whatever stock was. 3rd I think?

 

[RX-1MAN]

Did you actually open up the airbox? Just trying to eliminate the simple stuff to check. Sounds like you've done the hard stuff and sled wouldn't run good before you took anything apart.

 

[Sudbury451]

Can't get the carbs off if you don't open the airbox?

 

[RobX-1]

Would you know if the previous owner had an aftermarket air filter kit on it and possibly removed the filters only and put the stock airbox back on? The reason I ask is that I have an ECP kit on my RX-1 that utilized K&N filters. Because these filters were not as restrictive as the stock air box, you also had to install different/lighter CV springs and larger main jets (eg. 165). If one was to put back the stock air box but not tear into the carbs and replace the springs and jets, thinking this might be contributing to your fuel/air ratio issue,

 

[Sudbury451]

I put a brand new carb kit in it. 135 main. 75 power. 17.5 pilots. All OEM. Everything that I took out was stock OEM

 

[74Nitro]

Airbox on?

 

[Sudbury451]

Airbox on/off doesn't make a difference. Checked for leaks. No leaks. Just put another new set of plugs in since installing the new coils and I can get the sled up to RPM now by very quickly feathering throttle from none to full a bunch of times and then holding. Still seems like a fuel issue to me but I'm out of ideas.

 

[74Nitro]

It should make a difference as they won't rev properly without airbox on.
Airbox is all stock?
Why did you change so many parts that didn't need to be changed? Needles? Jets? Coils? Put the stock ones in.

 

[Sudbury451]

Coils were arcing very badly on the head. Had to be changed. The sled sat for 8+ years with fuel in the carbs. Figured it was easier buying a brand new OEM kit than cleaning everything. I was thinking about throwing all the old carb parts into my ultrasonic cleaner and putting them back in. Have tried everything else

 

[Sudbury451]

It should make a difference as they won't rev properly without airbox on.
Airbox is all stock?
Why did you change so many parts that didn't need to be changed? Needles? Jets? Coils? Put the stock ones in.

And yes whole sled is bone stock. Previous owner was an old man who drove it into a tree back in 2009. Bent some front end Hood supports. Parked it after that until my old man picked it up in the fall

 

[maim]

the little o rings are all in place under the cv caps on the carbs? brother had one split and said it ran dumb until he replaced it.