rxrider's Turbo Garage - pics back, will continue

[rxrider]

UPDATE - March 31. - Installing second BOV. Adjusting track. Adjusting revolver settings. Playing with sorce for pressurizing the float bowls.


What is wrong in these pics?

Whatever it is, it's not working at all. HAHAHAHA I should have known, but I just had to try and see what happened. What did I do wrong?


I did install a second BOV, I reinstalled the original MCX Mitsubishi BOV to help dump pressure from the plenum faster when chopping the throttle. I have been hillclimbing lately and have throttle chop when going vertical, none when flatland riding.

I went with 2 & 4 on the revolver setting in my ZX-2 skid. Preload at 3. Stock limiter strap. It was a big improvement in smoothness and it felt a lot softer to ride without giving away any in the g-bumps and moguls. I did not loose any steering ability cause of the high keel on the Apex mountain skis I run, nice improvement.

Only problem last time out was track ratcheted when hard on throttle and at high speed accelerating.

 

[rxrider]

UPDATE - April 4th - Testriding.

Installing a second BOV BlowOffValve in the Intercooler plenum was a great add on that works extremely well, no more throttle chop whatsoever. I already had the Vortech Race Bypass installed in front of the Intercooler. Although the Vortech removed turbo flutter it apparently wasn't able to prevent pressure to flood the carbs when I let off throttle abruptly. This is where the small Mitsubishi BOV (it was originall installed in the IC plemum but I removed it when installing the Vortech) comes in and lets off pressure on the carb side of the Intercooler core, thus quickly reducing pressure going to the float bowls when letting off throttle. Bleeding off pressure in the plenum helps reducing fuel pressure in the floatbowls thus it avoid pressure to build flooding the engine. I can now let the engine build full pressure and then shut the throttle close and wack it WOT and the engine is right there. What a great add on that was

The 2-4 revolver setting was not a good idea running 285 HP, I got severe track ratcheting even when running the track at spec, specially at higher speeds at WOT it started to ratchet. I allways let off throttle if I hear it ratcheting, it's very though on the drive shaft. I have to go back to 1/4 and check track tension again.
EDIT: By changing the revolver from 2/4 to 1/4 the ratcheting disappeared, sled runs very well in all kinds of condition. I'm happy with it and will keep the current settings. Preload are at 4.

Trying to pressurize the float bowls from the engine side of the carbs does not work. I forgot that when you give it throttle the vacuum starves the engine for fuel and it will die. NOT WORKING.

 

[rxrider]

UPDATE - April 5th - Clutching and "Stock carb spring mod" for MCXpress turbos.


When testriding on the lake yesterday I found that I have a dip in rpms at higher speeds. To keep the rpms in check for the whole WOT run I removed 2 grams of weight from the tip of the SuperTips weights. No pics taken, primary clutch work has been covered earlier.


My friend Mikkel told me about a mod he had tested in his sled with great results, the "Stock Carb Spring Mod". This mod removed about all the lag he had in his sled, it is very responsive I can tell after watching him doing test runs from a dead stop.

Here's how it's done. On the stock carb springs, find the end of the spring wire count 4 rounds including the top round of spring wire and cut the spring exactly at the same position as the end of the wireing is. This would be exactly 20 millimeter or 0.78 inch from the end of the spring.

No pics taken, forgot to bring my camera out yesterday. I will bring my camera out in the garage this evening and take pics of a set of stock springs I have laying around. I will mark them to show where to make the cut and post the pics in this post later on this evening.

Here we go.

First pic shows a stock unmodified carb spring and the piece I cut off the modded stock springs (sorry I have no pics of the modded springs as they are inside my carbs, don't really care to take carbs apart)

Next pic shows you the piece that you cut off.

Last pic has a black marker on the stock carb spring to point out where to make the cut.

This mod might work on other carbed turbo sleds as well, but I have no way to verify it.

Jan-Ove
rxrider

 

[rxrider]

UPDATE April 8th - Testride stock carb spring mod. Clutching changes. PART 1.

Stock Carb Spring Mod worked very well. At the same boost level top end rpms went up at least 400 rpms to 10700-10800 shift rpms. Throttle response was very good, except when giving it WOT from a very slow cruise where I got a burble until it cleared out and she ran like a rocket. Giving it wot from higher speeds sled responded very fast to throttle. All in all I found a few more HP cutting down the stock carb springs.

The carb springs are a work in progress. After the ride I have cut down the springs another 12 millimeter.

The polygraph aka WBO2 tells me that she is going fat when giving it WOT, she goes high 9s to low 10s AFRs right away when giving her WOT then clears up going into the 11s AFR. I believe that the carb springs are still too stiff not lifting the throttle slides fast enough thus creating a huge vacuum over the needle and jet pulling too much fuel when there is still little air available. This happens at vacuum just before boost kicks in, and when boost kicks in there is way to much fuel and she goes burbling. I will have to make another testride to verify what changes the last spring cutting creates. Stock carb spring length are down at 83 millimeter.

Anyway, I will have to install more weight to the tip to bring rpms back down to 10400 where she makes the best power.

 

[rxrider]

UPDATE April 8th - Testride stock carb spring mod. Clutching changes. PART 2.

Holy pop, after cutting the stock springs down to 83 millimeter, I started hitting the rev limiter. I had to throw more weight at her. I went with 3 more grams in the middle hole (2 x 7 grams tungsten) which is max. Weights are now at 7-14-2 for a total of 85.2 grams each.

Rpms go 10000 right after WOT from a stand still, a few tenths of a second later it goes 11300 hitting the limiter, it goes 10800 shift rpms up to past 160 kms or 100 mph, then it settles down at 10400 past 200 kms or 126 mph. Throwing in 3 more grams in the middle might hold it off the limiter. I might have to remove tip weight if top end rpms drops below 10400.

BTW this is at 15 lbs of boost, and I have 1 lbs to spare, I'm safe running 16 lbs on 98 octane RON pumpgas

AFRs are very close to what I saw running the Holtzman silver carb springs.

 

[rxrider]

UPDATE April 17th - Testride stock carb spring mod and clutching changes. PART 3.

To fix the wot richness and little burble I had going wot from a standstill I lowered the needles 1 clip position to position 2 to lean out the 5k-7k rpms area where it went high 9s to low 10s. Now it goes like 10.2-10.3 from a standstill then goes into 11s past 7k rpms.

My friend rides the same sled as I with about the same setup carbwise as i do. He said cutting down carb springs 32 millimeter took away from his low end responsiveness. I have a spare set of stock springs, I will cut them down to 20 millimeter and test then with my current carb setup and see if 20 millimeter cut is better than 32 millimeters cut off the stock springs.

I will have to take off all tip weight as rpms drops down to 10200 when approaching speeds past 100 mph. My new STs setup will be 7-14-0 inner to outer hole for a weight of 82.2 grams each. Dalton Black/Green primary spring. Dalton 54/48 helix with Yamaha white spring wound at 60 degree or 3+3 settings.

 

[rxrider]

UPDATE April 18th - Ran into a snag, front tunnel heat exchanger got hit by a few studs breaking loose taking out the exchanger.

Under a high speed pass a few studs did break off penetrating the front tunnel heat exchanger. Luckily the sled was not run very far and the leakage was not catastrophic judging from the amount of coolant lost on the trail just before parking the sled. Once parked some friends spotted the leak, I turned off the ignintion and it all of a sudden dropped a huge amount of coolant out the holes in the cooler.

I had to hike to town to pic up my car and trailer to trialer my sled back home. I had ridden out from home this morning.

At home I tore it apart the very same evening, here's what I found.


Coolant dumped at the parking lot.

Ouch. Bummer.

I have ordered a new front tunnel heat exchanger, while at it I also ordered a new left side running board heat exchanger because it has started to leak, the weliding done to it before this season did not hold up.

I hope to have her up and running before next weekend.

 

[rxrider]

UPDATE April 19th - Removing left running board heat exchanger. Removing all studs from track.


Running board heat exchanger removed.

First I removed the hose in the front of the left heat exchanger draining what's left of coolant. I then removed the hose at the rear and even more coolant came out. Coolant was clear and clean, I couldn't find any signs of a head gasket leak. There were no oil, no black silicone, no signs of combustion gases.

Second I started removing rivets. Before removing rivets I marked the ones in need of removal with a black marker pen. I used a thin chisel to punch out the steel rivet core and then used a 5 millimeter drill and a wisegrip to remove the rivets. I use to apply the wisegrip on the back side to hold the rivet steady, then I drill the rivets head until it falls off, with the wisegrip I can now pull out the rivet. This way I avoid drilling out the holes in the frame too much.

Last work for the day was to remove all 162 studs from my track. The track is worn and can't take the strain from running studs anymore. By removing the studs I hope it will survive the last 2-3 weeks left before seasons end.


Skid is in very good shape after 2000 miles of hard use. It has rubbing marks from the track at a few places but nothing major. My friend also running a ZX-2 136" in his Attak have found the reason to why studs are hitting the rear bulkhead and exhaust pipes. When the skid compresses the 4 fins on the upper side of the rear arm pushes the track upwards in the middle when the skid is completely compressed forcing the track and studs upwards even further that it would have without the fins. My fins are severely worn down because every time the skid compresses, the fins touches the track when pushing the track upwards, thus they wear down.


Track ready for stud removal.

Studs removed from track. I had a lot of broken and bent studs, even a few pull throughs. One of the pull throughs did take out the front tunnel heat exchanger.

 

[rxrider]

UPDATE April 20th-25th - Installing heat exchangers. Installing a new track. Installing new '07 seat.


Installing front tunnel heat exchanger. Before installation I had to remove the damaged heat exchanger. First job was to remove all the 26 rivets holding it to the frame. Next I had to remove one of the treads for the chaincase bolts to be able to get the exchanger out. I also had to remove the bottom part of the frame underneat the engine to get to the coolant hoses. The bottom plate is the part that the inspection lid is bolted on to. It was another 30+ rivets to remove but now I had very good access to the hoses. At last I had to remove all hoses connected to the exchanger, one on the left, one in the middle and one on the right. I also had to remove the air bleeder hose going up to the thermostat housing.

With the front tunnel heat exchanger out I moved over the hoses. I damaged the short hose going out to the right so I made a new one to replace it.

To be able to install the short hose on the right hand side of the exchanger I decided to remove the steel tube passage that goes thru the frame wall. The steel tube have been removed in this pic.

When all hoses was moved over from the old exchanger and the air bleeder hose installed on the new exchanger I installed it into the tunnel. First I routed the thin air bleed hose up to the thermostat housing and connected it to the fitting. Next I placed the exchanger in position and riveted two of the upper holes to hold the exchanger in place when installing hoses. I installed the centre hose to the steel tube inside the engine bay, and then the left side hose to the exchanger. Now I went on and riveted all holes on the sides of the exchanger. Then I went on to install the short steel tube (passing thru the frame wall) in the short hose on the right side of the exchanger. The short right side hose was already installed in the cooler. I pressed the steel tube into the new hose and riveted the steel tube to the frame. I also changed out most stock clamps with real hose clamps. At last I riveted the remaining holes and the front tunnel heat exchanger was done.

Installed the bottom plate and the inspection lid.

While at it I have checked all rivets and changed out those in need for replacement.

Now onto the left side heat exchanger. Ready to install.

I put the cooler in place and riveted it to the frame and running board. Next was connecting the hoses in the front and in the rear.

Temps outside at mid day, +0.1C or 32F

Installing the track.

To make install of the drive shaft easier I placed a bar into the track to make room for the drive shaft install. This way it's breeze installing the drive shaft into the frame.

I always keep bolts and nuts related in separate boxes to make install easier. Don't have to search for parts to install and it's way easier to see what goes where when done this way. These are the parts going in at the left hand side of the drive shaft and the part for the secondary clutch.

With the drive shaft in place I started by installing the left side drive shaft bearing. Before installation I had cleaned and repacked the bearing. I also had to buy 2 new set screws because they were missing on tear down, I probably forgot to tighten when changing out the bearing :-(

Then I installed the plate holding the bearing in place in the frame and I also installed the speedo picup sensor.

Next I installed the chaincase to the frame and assembled the gears and chain.

To install the skid I used the same trick with a rod to hold the track open to ease the installation.

Taking a break. Shot some pics outside my house.

The sleds inside the garage.

My driveway.

The road where we live. It is still covered with snow in the direction where the nearest snowmobile trail is I can still ride out from my garage.

The skid inside the track, ready to install bolts.

To ease the installation of the front skid bolts I placed a floor jack underneat the front end of the skid and jacked it up some. Then I lifted the front arm up a little to align the bolt holes, installed the bolts with blue loctite on them.

To ease the installation of the rear skid bolt I placed a piece of 2x4 on the floor to use as leverage. First I lowered the rear of the sled so that the rear shaft got into the tunnel, then I used the leverage and aligned the rear shaft bolt hole and installed the bolts with blue loctite on them.

At last I torqued the bolts to spec at 68 Nm or 50 Lb-Ft.


The skid installed.

The track I replaced, it had 3 studs pulling thru and were in pretty bad shape. I didn't thrust it anymore so it had to be replaced.

My new track is not going to be studded this season. Maybe next season, but I have to come up with a solution to prevent the charge tube, exhaust tube and other stuff inside the tunnel from beeing damaged by the studs, shorter studs maybe.


Last work for the day was installing a new '07 seat that better matched the color scheme of my sled, was a nice upgrade, it made the sled look so much better

rxrider wanna go riding
I will go saturday morning

 

[yamaslob]

That blue seat does really pull the color scheme together very well. Nice RX1 brother

 

[kinger]

Very nice! Most people run and hide like babies on the front heat exchanger, how long did it take to you remove all those rivets and reinstall?

The apex seat on mine made it look like it was a 07+ I was real happy with the look and its nicer and i get storage

Happy riding we are DONE and have been for over 2 months now.

 

[rxrider]

yamaslob - Thanks for the kind remark It sure looks a lot better than with the black and grey seat.

Kinger - Well I was not too happy before I figured out I only had to remove the bottom aluminum plate underneat the motor. It took two nights to tear everything apart, including taking out studs from the damaged track. It took 4 days to get the new coolers and the seat. I ordered the parts the day after my mishap. While at it I checked all rivets I could get to and changed out a bunch. Installing both coolers and frame parts was done in a days work. Installing a new track, skid and drive train took another day of work. Total down time was 8 days. I could have finished it earlier but I had to get hold of a track, which I managed to find the night before I finished off the sled. I was out today and it ran just fine With the new seat and 5.9 kg or 13 lbs of weight removed from the sled it is much more plush over the small bumps and even better in the moguls. I love my sled and may keep it, it's too good of a sled to give away for cheap.

Jan-Ove

 

[rxrider]

By adding a new track without studs, cut out to run extros, clipped every third, total weight reduction since last year is 27.7 kgs or 60.9 lbs.

 

[rxrider]

UPDATE May 2. - Straighten out the front suspension, right hand side. I had a major mishap :-(

While climbing a mountain on spring snow I had a terrible mishap. Close to the top I encountered a rock, what to do, give it wot and try to run over the rock or slow down trying to steer clear of the rock. I did choose to slow down but were not able to steer clear of the rock and BANG, I hit the rock and got thrown off the sled. Luckily I managed to get on my feet in a hurry, I jumped up on the sled while it was on it's way backwards down the mountain, I hit the brakes and the sled dug in the soft spring snow. Started up the engine cause it died on impact, gave it WOT and managed to continue the climb without getting stuck.

On the top I shot a few pics.

I bent the A-arms way back and the spindle looked like a banana. The sway-bar broke as well.

This view is why I climbed the mountain

Uhhhh - blush - another pic of the broken from suspenion.

When home I jacked up the front end of the sled and removed the shock and ski.

The broken sway-bar, 11 millimeter Pioneer Performance bar. Where it broke it had rust on it, telling me it has been a crack in the bar for some time waiting to break up, and the impact caused it to break in two.

I removed the spindle and started to straighten out the A-arms, it took some slamming, hammering with a sledge hammer, bending with a steel bar and a 2x4. At last the A-arms were pretty straight, but I also had to change out the right hand spindle. Luckily I had one laying around from an earlier mishap, this spindle was hardly bent so I could use it. The spindle bolt was not bent at all.

The day after me and my friend went riding. All worked well, but I forgot to adjust ski alignment/toe out so steering was a bit funny. I actually had toe in by about 1/2" or 12 millimeter.

After the ride I adjusted the toe-out to 3-4 millimeter on each side for a total of 7-8 millimeters toe-out.

 

[TT]

Good to see that the "baby" is back in one pice!

Where you safisfied with the carb spring mod?