mcx turbo pops at hi revs?

[woodies]

what the heck is going on? added weight and came off the rev limiter and pulls hard but still pops?really need help guys!af numbers are good in the 13 but then see 15's at full boost!do i need to reflash? mxc turbo without head shim) or more weight?less back shift?

 

[BigFish BC]

wow should be around 12 a/r at full boost something wrong it a lean pop.

 

[woodies]

let me start again. i got this sled from colarado so hi altide compared to here!we ride 2500 to 7000 ft. sent the controller back for reflash to get it good. is better for sure but still popping at hi revs? added weights and better but do i need to keep going? it still pops below 8000 rpm? very hard to find anyone in sask. with any knowledge of turbos!

 

[BigFish BC]

if its poping below 8000rpm then yah the poping is caused by it going so it needs more fuel but make sure its not hitting the rev limiter because that will cause the a/f to go lean & it will pop.sometimes the rpm guage will not move as fast as the revs come up so it will seem lean but is actually just hitting the limiter.try adding more weight first to see if it helps.without the head shim you will make more power so you will need more weight than one with a shim at the same boost.

 

[Snowfix]

what the heck is going on? added weight and came off the rev limiter and pulls hard but still pops?really need help guys!af numbers are good in the 13 but then see 15's at full boost!do i need to reflash? mxc turbo without head shim) or more weight?less back shift?

If you bring your revs up slowly on an open stretch you can see if it is the clutching or not. if it's still there i'd say your extra injectors in the plenum aren't adding any fuel.

I rode with a guy that had the MCX kit and the harness that plugs into the control box wasn't making good contact. He had to reseat the pins.

 

[SLY]

Do you have the external fuel pump? Also, check the fuel filter.

 

[snoughnut]

I had the problem with the connector controlling the second set of injectors in the plenum. Snow pack from a wipeout caused the problem. Used a hairdryer to melt/dry it out. If second set of injectors aren't working the sled will pop at about 7200 rpm (on Apex). It won't pull 8000 rpm. (redline on Apex is 11000 rpm) And there will be a noticeable loss of acceleration, so much so that when you correct the problem it will leave you laying flat on the ground when you pin it.
I'm not sure about the Nytro clutch, but I don't think there is`a big enough weight to throw at the Apex stock clutch to keep it off the rev limiter in lower elevations. (I'm at 16lbs boost, 300+ hp.) Especially in set up snow conditions.

Snoughnut
------------------------------
Western Canada

 

[Duke]

Maybe its a spark plug ?

 

[Turblue]

Ok this is the deal with my Apex.......It is a 2006 MCX....I was having problems with it popping and cutting out...when I accelerated it looked like it was popping @ 8500 to 9000 rpm.....after many head scratching rides that year, it was my clutching and the mcx efi box.....the 51 deg helix and purple cat spring set @ 1/0 helped with hitting the rev limiter....it would hit the rev limiter and only show 8500 -9000 rpm....need to load up the engine and have the heavy spring in there for back shifting....the other problem I was having...the mcx efi box was getting wet and screwing around with the injectors....moved the box and solved that problem.....give me a shout if you have any questions 403-866-6626 Shawn

 

[woodies]

thanks guys. any way to check that the injectors are working? shawn snoughnut said 11,000 rpm for apex? if so why was yours hitting? guages that slow or? thinking of dalton weights like my cat or is there better? what rpm should i be aiming for? argh!!!!!!

 

[woodies]

just thinking(i know smoke show) could i unhook the controller ? would this hurt anything? would let me know if the wiring was problem maybe!

 

[snowy1]

you can unhook the controller and if it does the same thing you know its in the injectors, most likely in the box or a leak or blockage in the vacumn line going to the box.

 

[Snowfix]

thanks guys. any way to check that the injectors are working? shawn snoughnut said 11,000 rpm for apex? if so why was yours hitting? guages that slow or? thinking of dalton weights like my cat or is there better? what rpm should i be aiming for? argh!!!!!!

You are shooting for about 8800 RPM.

 

[sledheadd]

On the nytro you can unhook the pressure line going to control box.Blow 10 psi in it while ideling, if sled dies then the extra injectors are working, if not more than likely moisture or bad connection.

 

[Turblue]

thanks guys. any way to check that the injectors are working? shawn snoughnut said 11,000 rpm for apex? if so why was yours hitting? guages that slow or? thinking of dalton weights like my cat or is there better? what rpm should i be aiming for? argh!!!!!!

yah my point was that its most likely hitting the rev limiter before you see the tach hit the limit.......how many lbs of boost? what do you have for clutching in your primary and secondary?

 

[woodies]

bwhaaha you know i have no idea memory is thinking bd8 weight with 3.5 grams weld under mostly on the tip. back is black with pink mark and the helix have no idea what the numbers are, but got 80 degrees in it seems to back shift good! one guy said to use bolts instead of rivets be heavier, then peen the ends.boost is turned down to 8 or 9

 

[mandingo]

would it be possible that the header is collapsed ?

 

[Washy]

This is my setup when I run in Saskatchewan. Hudson Bay

8bu-00 weights fully loaded.
14.5 rollers
B W B primary spring

47 degree helix
Pin wound to 70 degrees

Running 10 psi with headshim.

Pump up your control box with a tire pump like the guy says above. If it kills the sled they are working fine. Sounds like you need more weight.

 

[woodies]

Thanks guys. Whats the rollers deal? They are changable i assume. Tomorrow is going to be a lot of clutching and tuneing.

 

[snowy1]

the 14.5 rollers are a must with a turbo, you need all the belt pressure you can get and you will beable to run less wieght.