rxrider's Turbo Garage - pics back, will continue

[rxrider]

UPDATE - January 9. - Testing idle AFR. Checking ZX-2 suspension bolt torque.

Idle AFR on a hot engine:
Warmed up the engine to operating temps. AFRs were 14.7 at idle 1500 rpms, perfect. Holding the rpms just below engagement at 4000 rpms AFRs were 14.2, acceptable. I'll leave it like this and will take her for a ride before making further adjustments.

Checking bolts, ZX-2:
- I set my Tengtool Torque Instument to 68Nm or 50 FtLb.
- I started by torking the 4 bolts holding the ZX-2 to the tunnel. All 4 bolts did move about 1/16 turn before reaching final tork.
- Next I went to the right side of the ZX-2, starting with the bolt holding the front arm to the rails, it was loose. It took 1/8 to 3/16 turns to reach final tork. Next I checked the remaining bolts except the rear shaft, all bolts were at final tork or higher and did not move
- Then I went on checking the left side, all bolts were at final tork or higher and did not move.
- Finally I checked the rear shaft bolts, both moved 1/4 turn before reaching final tork.

I red the Service Bulletin 1 from ADBoivin regarding tork procedures.
- First you have to break in the skid, and at 160 kms or 100 miles you shall retork all bolts.
- Second, you shall ride your sled another 160 kms or 100 miles, and at 320 kms or 200 miles you shall tork all bolts in the skid to spec. If bolts are still coming loose you have to make steps to correct this situation, the description of this procedure is found in the service bulletin.

Conclusion:
I have only 80 kms or 50 miles on my ZX-2. I was not expecting to find any loose bolts this early. I'm glad I checked the bolt tork this early tho, who knows how long it would have taken for the loose bolts to unscrew themselves.

After finishing the intial break in and bolt check procedures, I will now check the following bolts for tork after every ride:
- 4 bolts holding the skid to the tunnel
- 4 bolts holding the front and rear arms to the rails
- 2 bolts holding the rear shaft in place
I will continue this procedure until I'm absolutely positive that the bolts are holding up.

Yeehaaa, it's snowing. We need it cause we have no snow at sealevel, only glare ice all over the place.

 

[rxrider]

UPDATE - January 10. - Adjusting limiter strap ZX-2 136"

After reading a post in my thread "ZX-2 performance review...."

http://www.ty4stroke.com/viewtopic.php? ... c&start=15

by NytroYK I decided to test the medium setting on the limiter straps. Manual says this is for off trail riding.

I do a lot of that and our trails are just tracks thru the off trail of nature. Our trails are on snow covered ground, no roads underneat. As a cause of this our trails are nasty.

NytroYK reported good results in similar conditions as I'm riding in so I went out in my garage and moved the lower bolt in the limiter strap from holes 1 and 3 to holes 1 and 4. This sucked in the front of the rails some and made the skid run more parallel to the ground, it still touches the ground in the front of the rails when lifting it and lowering it down. I left the revolver in the 2 and 4 position, with spring preload at 5.

Will go out this weekend and ride it.

 

[rxrider]

UPDATE - January 13. - Testriding with limiter strap in middle position ZX-2 136"

Thanks NytroYK - Running the limiter strap in the middle fixed my problem with too little ski pressure. I still have perfect transfer when giving it WOT.

I feel that running the limiter strap in the middle made the skid a tad stiffer. I rode the sled 2-up with my brother in law and it did not bottom out at all and MAN the ZX-2 did move nicely underneat the sled with 430 lbs of rider and passenger.

I will back off to 3 on preload and test it there. It felt a lot stiffer over the stutters and small bumps than before going to the middle hole.

I rode the very same trail as last time out and I'm very happy with how the ZX-2 takes the nasties with ease. Now with more control from the increased pressure on the skis

 

[rxrider]

UPDATE - January 13. - Testriding, checking AFR levels.

Update on jetting, AFR. On the lake January 13.

Idle hot: 14.3-14.5
Takeoff rpms: 13.5
Driving slow: 13.5
Cruising 0 lbs of boost: 13.0
Cruising 5 lbs of boost: 13.0
Cruising 10 lbs of boost: 13.5-14.0
WOT 0 lbs: no data
WOT 5 lbs: no data
WOT 10 lbs: no data
WOT 16 lbs: 10.9

Temps on the lake today were -6C or 21F
Altitude: 100 meter or 300 ft

Jetting:
Main jets = 135
Pilot jets = 17.5
Pilot screws = 2.25 turns out
Needle = 2 position (lowered 1 from stock)
Stock carb springs

I get a little hesitation off idle, that I can live with. AFR is 13.5 at engagement, perfect. It does not die when letting off throttle from WOT 16 lbs to no throttle. It does not run pour when riding slow for a mile. ON and off throttle it responds just great and it doesn't miss a beat, I'm pretty happy with it.

- Down low is OK, won't touch it.
- Needles, I may raise them to stock. 13.5-14.0 AFR is kinda lean for 10 lbs, somewhere around 1/2 throttle. What do you guys think? Should I go with stock needle position running stock carb springs?
- WOT was 10.9. I don't think riding in -18C or 0F temps will get it up to 11.8-12.0. I have a set of 132.5 on order to cure the fat WOT.

 

[rxrider]

UPDATE - January 15. - Jetting, changing needle clip position.

I decided to go to stock setting on the needle and spring.

My jetting after the change:
Jetting:
Main jets = 135
Pilot jets = 17.5
Pilot screws = 2.25 turns out
Needle = #3 position
Stock carb springs


Here we go - If you have a MCXpress turbo, you may loosen the charge tube hose going to intercooler and pressure signal hoses going to the slides to make removal and install of the carb caps easier.

On a non turboed sled, start out by removing carb caps and springs.
On mine I removed STM carb caps and springs.

Took out the slides and needle assy.

Inspect the rubber diaphragm, if damaged it needs to be replaced with a new one. A few of mine were squeezed together the last time I installed the carb caps causing the diaphragms to go out of shape. I warmed the rubber with my hands and carefully got the parts squeezed together back to original shape, it may take a while but if you're careful they will retain stock shape.

To remove the needle assy from the slides I used a 45 degree plier. Be careful when you take out the plastic plug that holds the needle in place, there is a small spring underneat the plug that may jump out of there. It did on the first one, luckily I were able to spot it on my garage floor a few minutes after it went missing

Here's a overview of the needle, c-clips, washers and spring.

Disassembling the needle assy before changing c-clip position, I'm raising the needle to the #3 position or middle position, the stock setting.

And onto assembling the needle combo. I installed the C-clip in the #3 position and reinstalled washers like shown in the pic below.

One washer goes on top of the c-clip, a plastic spaces goes under the c-clip and the second washer goes underneat the plastic spacer, shown in pics below.

Time to install the needle combo into the slide. Remember, there are both the plastic spacer and the washer underneat the c-clip with nothing holding them in place. Gently lower the needle into the slide, hold the washer and plastic spacer so that it doesn't fall off the needle. Put the tip of the needle into the slide and gently lower it into the hole. When the tip of the needle comes out the bottom of the slide, grab it and gently lower the needle into the seat in the slide. Check that both top and bottom washer are in place.

Install the spring into the plug like in this pic.

Use a plier and lower the plug and spring gently into the slide, the spring is supposed to go on top of the needle and rest on the upper washer. Just press the plug enough to not jump its seat. To check for proper install of the spring, gently press the tip of the needle upwards, it shall give away and when you let off pressure it shall bounce back out by the force of the spring.

With the spring in place gently press the plug in place with at plier. Be careful not to break the seat in the slide or the plug.


Now it's time to install the assembled slide needle assy into the carbs. Gently position the slide into the carb, wiggle the slide a little if the needle does not hit the needle jet right away. With the slides in place, check that the rubber fits correctly around the edge of the carb. If they have grown too much and will be squeezed by the carb cap, they will shrink by placing them in a fridge for a short period. Install the carb springs into the slide.

Place the carb over the carb and slide in into the spring. Lower the cap peripendicular to the carb and straight down onto the carb. Make sure the bolt holes is lined up before lowering the carb cap into place. Remember to have the bolts and philips screwdriver at hand cause you cannot let go of the carb cap or it will bounce off from the spring pressure. Tighten down the bolts evenly, a little at the time.

Done.


Install plumbing if you have a turbo.

Done.

 

[rxrider]

Went out riding the sled today. It was warm, +4C or 39F. Not perfect for testing AFR #s. If anything I'm rich on top and down low. When giving it WOT AFRs were mid 10s. When cruising 30-50 kmt or 20-30 mph at 1/8 throttle or less, still at vacuum, my gauge showed low 11s. Giving it more throttle to get it slightly into boost it would go 12.5-12.8, pretty OK for a bad air day with warm weather and low atmospheric pressure. When giving it WOT when cruising showing low 11s, it will sputter some and when it clears up it just goes like crazy, boost is priceless. I will not make any changes to the jetting until I have tested in real winter conditions, at least -10C or 14F.

 

[rxrider]

UPDATE - January 17. - Adjusting Fox Floats. Adjusting track tension. Checking ZX-2 bolt torque. Adjusting ZX-2.


Adjusting Fox Floats:

The last time out I gave her one heck of a time. I found the Fox Floats up front a little too soft, need a little more pressure. I figured 5 lbs extra would do the trick, went from 70 lbs to 75 lbs.

Place a floor jack under the belly pan and jack the sled up until the skis barely touches the floor.

Remove the caps from the FFs filler necks.

Screw the FF pump into the filler threads finger tight, FF pressure shows up on the pump dial. In my FFs the pressure was 70 lbs, same as last time, no pressure drop even after a serious bottoming. Nice

Add pressure with the pump until desired preload pressure is reached. In my FFs I added 5 lbs - now at 75 lbs preload pressure.

Reinstall filler neck caps.

Release the jack and remove it, the job is done.

Adjusting track tension:
No pics taken. Lift the rear of the sled until track is off ground. Loosen rear shaft bolts a little, both sides. Place a socket wrench at the adjuster bolts thru the track window, adjust the until required track tension is achieved, both sides equally. Then check for alignment. First you have to rotate the track to have it centered, this can be done by hand of by running the track on the engine. If out of alignment adjust the bolt on the side where the track is out to, adjust a little of the time until the track is in center. Check track tension again. Still too loose, adjust by turning both bolts equally. When proper tension is achieved check for alignment once more. Tighten rear shaft bolts to 68 Nm or 50 FtLb. Done.


Checking ZX-2 bolt torque:
No pictures taken. I checked all bolts going into shafts. Set the torque wrench at 68 Nm or 50 FtLb. No bolts were loose on the right side of the skid, all were at spec, no movement. On the left side the front tork arm bolt had minor movement before the wrench clicked out, nothing more than 1/16 turn at the most. Checked the 4 bolts holding the skid to the frame. Both in front were at spec, no movement. Both in the rear had minor movement before clicking out on the wrench, about 1/16 turn or slightly more. I had a very har encounter with a pile of ice on the lake where I bottomed out the rear suspension on take off, and a very hard landing on the flat ice from 2 meters or 6 ft. The ZX-2 did survive without any damage so did the FFs up front


Adjusting ZX-2:
I said I would not go up in preload until I had done the initial break in. I've changed my mind after yesterdays riding. When thinking about it I decided to go to 4 in preload before the next ride this weekend.

I put the ZX-2 spring preload adjustment tool in there and rotated the wrench clockwise until the 7 step adjuster on the shock jumped from 3rd to 4th position. Repeat the procedure on the other side of the skid, remember there are dual shocks in there. Make sure both shocks are adjusted equal. Here's a pic when adjusting spring preload.

 

[rxrider]

UPDATE - January 18. - Checking studs, outer band.

I have no pics, studding ain't that interesting LOL

Yesterday I noticed there were a few studs on the outer band starting to rip through the rubber on the inside of the track. I run 162 studs in a 2-4-2-4-2 pattern, I have the outer band studded every other row. When studding I drilled holes for 216 studs just in case I needed more studs, I drilled 4 holes in every row, 2 in the middle and 2 in the outer band on every row.

To save my track I moved the studs on the outer band one row forward, to the holes not in use. Doing this most likely saved my track from ripping apart. Studs on the outer band was moved before any damage were done to the track. I'm glad I noticed what was going on.

great to be out in the garage this evening brought beer

Going out to ride my sled tomorrow

 

[kinger]

Awesome post, thanks!!!

 

[rxrider]

UPDATE - January 19. - Carburetor work - changing main jets and adjusting pilot screws.

No pics taken. Too much fuel and antifreeze, wouldn't risk my camera.

OK - I was out on the lake today. I did some testing on the AFRs running it on a variety of throttle positions and boost levels. Here's my observations.

Temp on the lake: -2C or 28F
Altitude: 100 meter or 300 ft

With this jetting:
Main jets = 135
Pilot jets = 17.5
Pilot screws = 2.25 turns out
Needle = 3 position
Stock carb springs

my AFRs were:
Idle hot: 14.3-14.5
Takeoff rpms: 13.5
Driving slow: 11.5 (not good)
Cruising 0 lbs of boost: 13.0
Cruising 5 lbs of boost: 13.0
Cruising 10 lbs of boost: 13.5 (1/2 throttle)
Cruising 12-14 lbs of boost: 13.5-14.0 (3/4 throttle cruising at 100-110 MPH)
WOT 16 lbs: 10.9

Driving slow is too fat, gotta go down on pilot screw. WOT is also too fat, gotta go down on mains as well.

With todays testing results I went out in my garage and took the carbs off the sled.
- Remove air-filter or intercooler
- Unplug TORS and TPS
- Unhook upper carb coolant line, plug the line to avoid spilling anit-freeze
- Unhook throttle cable and chocke cable
- Loosen allen bolts holding the carbs to the carb boots and remove carbs from boots
- Unhook lower carb coolant line, plug the line to avoid spilling anit-freeze
- Unhook carb heater lead, right hand side underneat the carbs
- Unhook fuel lines and block them off to avoid fuel spill
- Remove the carbs from the sled
- Drain the carbs
- Take the float bowls off. Tap the screwdriver gently to shock the brass screw loose from the aluminum threads. Then carefully unscrew the brass screws. If the screwdriver slips the philips head, tap the brass screw with a socket wrench extension. This will flatten the brass screw to some extent, often enough for the screwdriver to get enough hold on the brass screw to loosen it. Again tap on top of the screwdriver to force it into the philips head to get the best possible hold, then gently unscrew the brass screw. I know they can be a pain.
- I removed the 135 main jets and installed the 132.5 main jets.
- I adjusted the pilot screws down from 2.25 to 2 turns out.
- Reinstall in the reverse order.

While installing the float bowls I took the opportunity and changed out 4 of the brass screws holding the float bowls in place, allen heads had worn some. Better change them screws before they cause me any trouble.

New carb setup:
Main jets = 132.5
Pilot jets = 17.5
Pilot screws = 2.0 turns out
Needle = 3 position
Stock carb springs

 

[kinger]

Do those dial a jets or something similar work jetting these things is such a PITA!

 

[rxrider]

UPDATE - January 20. - Carburetor work - changing needle clip position raising needles. Installing carbs back into the sled.


My current carb setup:
Main jets = 132.5
Pilot jets = 17.5
Pilot screws = 2.0 turns out
Needle = #4 position (raised 1 notch from stock)
Stock carb springs

I will take her out on the lake later this week for the final carb tune test riding I hope. I'm pretty close on jetting so if she runs great everywhere I don't care what the AFR meter says as long as she's not too lean up top that is.

Thanks to lakercr and Skydog for their input on jetting, your advice and suggestions have been very helpful to me

 

[rxrider]

UPDATE - January 30. - Adjusting the ZX-2. Adjusting pressure in the Fox Floats.

I have been running the ZX-2 with preload at 3, revolver at 2/4 and limiter strap at 1/4. Better but not good enough.

After reading the manual once more I figured I would go with the manuals recommendation for a 200+ HP sled. Manual calls for revolver 1/4 when running big power, and I do. I put the limiter strap back to the stock 1 and 3 hole, changed the revolver setting to 1 and 4 and set preload at 4.


I have been running the FFs at 75 lbs, too much pressure. I have now backed it off to 65 lbs.

 

[rxrider]

UPDATE - January 31. - Carburetor work - changing needle clip position, lowering needles.

My sled was still running fat at slow cruise speeds. I have now lowered the needles to stock position. Jetting is stock except 132.5 mains. I'm not touching it anymore

 

[kinger]

LOL MCXpress saved you a lot of time but like a true tinker (liek myself) you had to find out for sure on your own!! I do it ALL the time. have fun with that animal!