Apex MCX problems.. need help

[snow_knight]

Went riding today for the first time ever on my new boosted apex.. guy i bought it from said it was setup for cookecity.. I was riding at arond 5,000 ft. today.. Anyways

1: Sled would only run out till like 9,300-9,900 rpms as soon as it got in this range it wouldn't pull anymore and made a funny blubber noise. a/f gauge was reading 11.4 idle 12.4 cruising and 13.1 wot until it hit the rpms, I would let off the throttle, the second i left off a/f would read like 16.1 for a split second then drop back down to 11-12... Could it be the fuel mapping?.. I burned about a 1/2 tank in around 28-30 miles?

2: I bought the Cr racing air intake kit, thought I had that hoseclamp on really tight around the filter.. we stopped about 2 miles before we got back to the trailor and it was still on.. Got back too the trailor and gone.. Looked for 2 hours till it got dark.. couldnt fit it, probably rolled into the creek along the trail.. Dont really feel like spending the that much money again to just get the filter.. What is the part # for the really big K&N..

3: I'm not sure what boost gauge is on the sled, it was on there when I bought it from chubby.. However its black and digital (red numbers).. At ideal it would read like 10-13 lbs. cruising down the trail it would read like 2-3.. and at wide open it would flash and read 0.1?.. anybody seen this problem.. faulty gauge?.. dont really know for sure..

Any help would be great.. Had a trip planned for this next weekend.. and would like to get this stuff fix.. thanks rocky

 

[Mountaintech]

Easy to replace CR Racing intake. Just buy some black ABS pipe.....couple of inches of 2",glue into a 4"to2" reducer, couple of inches of 4" pipe, and a 4" end cap. Lots of holes to drill but at least it doesn't cost $200+. Then all you need is a Precharger sock. Works great. I've built 2 so far.

 

[snow_knight]

ya never thought of that.. probably would work

still need to get my first question answered.. thats the big one for me... anybody else

 

[snow_knight]

Going to pull the plugs tonight and see what they look like.. anybody else have any ideas

 

[summitboy]

What year of Apex and what year of MCX ? Ditch the boost gauge and get a Autometer 2 5/8 liquid filled boost gauge. Yours sounds like it might be having issues.

 

[summitboy]

Apex

What year of Apex and what year of MCX ? Ditch the boost gauge and get a Autometer 2 5/8 liquid filled boost gauge. Yours sounds like it might be having issues.

 

[snow_knight]

its an 06 apex.. and not sure on the kit.. it was already installed when i bought the sled.. I bought it from chubby (old forum).. trying to get the plugs pulled now.. never done it before.. not reall easy

 

[BigFish BC]

pretty sure his was a 06 kit too

 

[Turblue]

I have an 06 kit and was having problems with it cutting out sometimes....If I accelerated across a flat open spot or climbing it seemed to cut out between 7000-10,000 rpm from what I could see from the tack......I went throught the sled all last winter from top to bottom

checked the tps via the display and volt meter
checked fuel pressure
changed map sensor
checked grounding and added another ground wire to the chassis from where the mcx box is mounted
checked all connections
sent the efi mcx box in twice to be checked
Found moisture in the mcx box a few times
removed the spacers on the TB to the motor for a tighter seal
removed the intercooler and check the mcx injectors(visual) while the sled was running to see if they were giving fuel as the pressure increased(used a pump and test gauge)
pressure tested the system from the turbo back to 25psi....alot of small leaks that I fixed

So over the summer I went through every wire connection and sent my box to mcx in Sweden, relocated the box to a different location so the water off the intercooler wasn't running on it creating I believe condensation/or running in through the lid.....installed new ss exhaust header pipes due to mine stock ones being collapsed, installed all new exhaust gaskets, installed a AF gauge

So far I have been out 2 days and it seems to be running like a top...I firmly believe that it had a lot to do with the mosture in the box...it also seemed to get worse as the day went on......hopefully the pain I went through will help.........If is really hard on gas I would check your tps first...

 

[snow_knight]

Talked with joel he thinks it might be a combination of fouled plugs and clutching.. Lets hope for this.. thats an easier fix..

 

[snow_knight]

Finally got the right plug socket.. will be pulling them tonight and replacing them since i'm in there anyways.. if there is something fishing looking i will post pics

 

[snow_knight]

pulled the plugs and they lookd good..all 4 were a nice coco brown in color.. one plug had just a little big on white on it.. but not much.. put new plugs in it anyways

Took weights out and weighed them.. 71 grams

Going to try to hook a mechanical boost gauge up.. and see what it is reading.. Cant find a thread on how to do a boost pressure test.. anybody???.. I see that directly above the injectors on toward the top of the intercooler (in the middle) there is a small hose about 3 inches long that is plugged.. Could I hook the mechanical gauge in there.. and get a good reading??

 

[Turblue]

All i did was hook up regulated air to the intake of the turbo and pressure to 20 ish psi....How many psi are you running for boost? If your running over 12 psi with that much weight and a stock secondary set up you are most likely hitting the rev limiter....I noticed it hits the limiter faster than what the tac show's....When its cutting out at 9900 rpm are you gradualy squeezing the throttle or punching it? Get a liquid filled boost gauge......you can see on my pictures the blue tee goes to the boost gauge and to the bov's from the intake downstream of the throttle bodies..

 

[snow_knight]

Well thats the problem.. dont really know what boost i'm currently running at due to faulty guage or not making boost not sure.. And it has an hcx secondary (heel clicker one).. Joel said it should be around 12 pounds if i didnt touch the boost controller (which I only check the fittings on)... I dont have that T on my sled.. my bov in under my intercooler.. he had a bung welded in on the charge tube and installed the bov there.. I'm going to get some pictures of everthing... maybe that will help somebody help me figue it out... So i'm trying to get all this figued out.. Wish somebody local knew there stuff to help me out..

 

[snow_knight]

hey finally found the which boost gauge was on my sled

http://store.summitracing.com/partdetail.asp?autofilter=1&part=CYB%2DA013E061Y&N=700+115&autoview=sku

anybody have good/bad luck with these?

 

[WOOD2]

What year of Apex and what year of MCX ? Ditch the boost gauge and get a Autometer 2 5/8 liquid filled boost gauge. Yours sounds like it might be having issues.

WORD!

 

[Pastor]

It has been our experience that the motor revs way faster than the tack can read acurately, so it is very possible that you are hitting the rev limiter even though the tack says otherwise.

We have a boondocker set up at 18 lbs and when it startes to run poorly on the top we just let off the gas a little and it cleans right up and still has all kinds of power.

We hesitate to change the clutching much because we have not had the sled in the most difficult conditions yet and perhaps under the heaviest loads it would not hit the rev limiter.

I very likely could be wrong but your symptoms sound just like ours did and we were hitting the rev limiter.

 

[snow_knight]

So what is are most people running for weight then.. The ones in my sled are 71g base heelclickers i belive.. know a lot of peeps are running supertips..?..

Hitting the revlimiter wouldnt be a blubber though correct?... It also would not create the sled not building boost?

 

[Turblue]

I have dalton base 70 's loaded up I think that would make them 78 grams...also I have a 51 deg secondary helix with the Alpine stiff black spring set at 1/0.....seems to be working fine.....I agree with pastor...when I was have rev limiter problems and let off the throttle a little bit...i had all kinds of power then, but if I tried pinning it ....it appeared to be lower on the tach....installed changed some clutching around and made a world of difference.....

 

[snow_knight]

Well I took everthing apart this afternoon.. no loose hose clamps.. barrowed a boost gauge to check mine but didnt get to try it..

Think I'm personally going to give up on it for now.. Take it to somebody that knows there chit about with these sleds.. I'm going to admit i'm kinda scared to screw something up on this sled.. So not real sure who i'm going to take it too yet... will have to try and find somebody tommorow.. any ideas?

Thanks for your guys help though.. I appreciate it.. helps me learn more an more about this 4 stroke thing.. still my virgin year with them