First post PLEASE HELP!!!!!

[Racegun]

I just picked up a 03 RX-1 with a MPI stage II turbo with NOS and am having some trouble getting it to run like I know it can. It seems to be running way too lean throughout the entire throttle range and it even is backfiring and popping on the top end. The AFR is reaching 15 and I have even seen 16. I am wondering if old race fuel or low octane would show a lean condition on the AFR? I pulled the carbs apart last night and it has 132.5 mains and 17.5 pilots and it has a 70 jet in the charge tube line. I ride 8-10K usually and am planning a trip to 4-5K feet elevation. I also noticed that one of the intercooler boots had blown off… could this be the cause?
PLEASE HELP!!!!
I'll post pic's later.

 

[TT]

Is this the MPI titanium version of the Bender stage 2 kit?

Unhock the tors to make sure it isn't messing thinks up.

The titaium chargetubes tends to run leaner than the stainless steel ones.

I had some issuse with the jetting when I first installed the kit (same kit as yours).

First of - do a pressure test on the charge side/compression side and fix all air leaks.

If you don't have billet Ts buy them! This will be the only good way to make sure your float bowls get a good pressure signal.

Set fuel pressure at idle to 4,5-5 psi.

Add a second pressure line to the cardslides to get them rise even.

To give you a clue on different jetting - I have both the stainless steel and titanium charge tube. I had to go to 145 main jets and pitot jet closed off to get good AFR readings on 5 psi. With the stainless steel charge tube and 135 main jet and 600 in the pitot I am rich at WOT. This gives you a clue on how different the charge tubes can run. This is @ 0-1500ft.

If there is a BOV on the kit - make sure you have it installed before the Pitot jet/float bowl signal. This can also mess up your jetting - been there done that - LOL

According to plent of guys on here - OEM carb spring are the only way to go. Shoot Skydog a pm and ask.

Dial the sled in with a 600 jet in the pitot - this gives you plenty of "room" to play with different boost, temp., alltitude etc.

 

[wantboost]

stop running at 15-16 afr's,you will destroy that motor

 

[Racegun]

Wantboost: I ran the sled one time the guy told me it was dialed in at my altitude I saw the AFR rise and I got out of it. I have been running 2 stroke turbo’s so I know when to say enough. R E L A X that’s why I’m asking the questions, thanks for caring though. LOL

Yes this is the titanium version this sled was the owner of MPI when it was new. So it has everything that MPI sold on it. It sounds like the 132.5’s are way too lean then. Can you tell me where you are with your pilots and needles? I bought some 135’s this morning, but it sounds like those might be too small. Also what should I see on the EGT’s at WOT?
It was also suggested to me that I get rid of the charge tube jet what is your opinion of this idea?

 

[TT]

What alltitude was the sled dialed in at? If same level as you - just leave them in and get everything sealed up before re-jetting.

You AFR readings will be way different with everything sealed up - you said that on of the carb boots was blown off.

Be 100% sure everthing is sealed up on the comp.side - if not you will be chasing you tail with trying to get good AFR readings - "been there done that - LOL "

I have richened the needles all the way to cure the mide range.

I personally like the pitot function. On my titaium charge tube it did work as good as on the stainless steel charge tube.

If you intend to run same boostlevel and alltitude all the time - block it off.

If not dial in with 600 jet in the pitot to have "room" to change your AFR-readings

Just my 2 cent.

 

[Racegun]

I sealed everything off and put new boots and clamps on the carb to cooler. He told me it was dialed in at 10-11K but I usually ride a little less than that with the occasional jump to 11,500. I think I will go ahead and put the 135's in and check the needles, if there is still room for adjustment I will richen one step just to be safe then take it up and ride it. If I am too rich at least I will be able to limp around. The guy I dought it from told me it was set at 18lbs, but I dought this setup will see those numbers. I saw 14lbs one time before the boot came off, but it was still too lean. I will probably set it at high boost and leave it, but I have not rode it enough to make up my mind.
What would the symtoms of bad fuel look like? I am going to drain it and run 110.

 

[TT]

Look into carb rings like on the MCX kit - so your clamps and silicon boots have something to grab on to. I don't have any trouble with IC blowing off after installing carb rings.

I think Ted Jannetty on the forum sells carb rings

 

[TT]

Did you see lean AFR readings before carb boots blew off? If so go bigger than 135 main jets.

Are you sure it was a 70 jet in the pitot and not a 700?

The kits came with 400 hex jet for high boost (10psi) and 700 hex jet for low boost(5psi).

The bigger jet in the PITOT the more air it bleeds off - and you get leaner AFR readings. The smaller jet or closed off pitot - you get richer AFR readings.

 

[Racegun]

Yah, I saw those today I was wondering if they worked. It looks like the boots I have need to be a 1/2" longer. (Not the first time I've heard that)
Do you know what pilot jet you have in your carbs?

 

[rx-hi]

Racegun
How much did you give for the sled I have mine for 6500 with mc kit and it runs. That Titanium tube sure makes a drastic change!

 

[Racegun]

The sled I picked up has everything MPI deals in, boss seat, NX nos, drop and roll, 162 X 16, billet wheels, light weight tunnel, Elka front shocks, light weight bat, Simmons ski's, Diamond S mesh hood, Racepac, AEM AFR, MPI roller clutching, and some other bling. I traded a very nice Rev with Aero turbo on it.
This sled has a few bugs, but I know they are nothing that I can't overcome.

 

[Racegun]

I ordered up billet carb rings, T's, and carb tops… top’s excluded, it’s the first time I’ve bought something so pretty that know one will be able to see. Hope they fix my lean conditions. Thanks for all the good information TT.

 

[Racegun]

I made a plug for the intake pipe with and air fitting on it and pressurized the system. I have a lot of air escaping directly under the seat on the right hand side through two small holes a couple inches apart that are tapped for screws; it looks like a mount for something it has a Boss seat on it so mayby whatever it was did not need to be there anymore. My question is: From what point forward of my air intake do leaks start to matter. I would assume those two holes would just be drawing in ambient air from under the seat and it wouldn’t really matter?

 

[Colorado Yamaha]

RX-1

Hi,

If your sled is the twin to this - except the tunnel is not black ... and you bought it from a guy in Colorado Springs, you may want to call Mtn. Tech Yamaha, Sean is familiar with that sled and may be able to help.

 

[Racegun]

Here she is like i promised.