Supercharged Apex

[pedsled]

Hi guys, I have a supercharged apex mtx that has had this problem from day1. It rips hard but when I climb a long run up a steep hill I get almost to the top and the engine flat out dies for a second or two! I let off the throttle and it comes back but by this time I have @#$% running down both legs and am lucky to get turned out and head back down. My guess is it is running out of fuel because the fuel system can't keep up, Can't find much help around my neck of the woods, has anybody else had this problem and know the cure? Thanks

 

[Barry Barton]

Hi I also have a sc apex haven't had the chance to get it out yet but u sound like your on the right track . what I need to no are u running a gems programmer and if u are set mode 4 up to 6 which will increase the fuel output to handle the alltitude u are doing.If u have any thing u need to no u can call me at 780-918-7846 I installed my own sc so ive been picking up from information from darren from e&s and he's been a lot of help so please call it would be nice to talk to someone who has a sc chow Barry

 

[pedsled]

Yes it is a GEMS controller, I had a gems on it and it got soaked and quit working so I bought a new one from Mountain performance and come to think of it it wasn't this bad with the original one. I did try different settings but no change, I did notice that after installing the new GEMS that when you start the sled it runs for a few seconds and then dies then I start it back up again and will stay running but the idle runs up and down never the same constant rpm. The original pulleys on there made way too much boost and would literally blow the throttle bodies off the engine so I got with mountain performance again and purchased every pully they had to mix and match and see what happened. with the original setup my boost gauge said 20+pounds the gauge only goes to 20 but it was past there at WOT and then poof! off with the throttle bodies. The ones I'm running now make it spike about 15 lbs then runs out at 10-12 lbs on the gauge. The throttle bodies stay put now but seems to run out of fuel on the hill climbs, thats pretty much my only real concern at this point and I don't even want to ride it like that. OH ya, If the drive belt from the crankshaft is too loose then it will shred all the teeth off of the belt so the next belt I put on I tightened down way too tight and the bearing just behind the pully blew out so I replaced it and tightened the belt again and it blew out in 2 rides again so I replaced it again and loosened the belt and made sure it wasn't too loose and the bearing seems to be holding up fine so far. other than that this sled rips hard and is a blast to ride but chugs the fuel down! I run 50/50 92pump and 110 VP and get almost exactly half the fuel economy as stock. If it would make it over the top of the hills I try to climb it would be way cool but with the motor stalling out almost to the top then I pretty much don't want to ride it anymore. After the last episode on the hill I parked it and finished out the season on my 86 phazer! how lame is that.

 

[Barry Barton]

Hello again are u running a stage 2 sc because your psi sounds to high for a stage 1. I have one set of pulls and I have it on the lower setting right now so I'm only pulling about 5 psi and about 180 hp, but if I flip the pulls it will go to 10psi at about 200 to 240hp with a 50/50 mix of fuel. I don't have a gauge on the sled so i'm not sure what the psi is at but mpi sent me the pullys so they will run this way also my bov valve is set for 10psi so I don't no how your psi is going so high without openig up because thats the saftey feature for the bov valve so u don't blow of your throttle body.And yes my sled has also shut off for no reason when I first start it but only once or twice and the iddle did jump around for a while but then I changed the fuel because the fuel I had ethanol in it so when I put some good fuel in it , it settled down for your problem I would call darren at e&s and maybe he can help u with the right combanation.

 

[pedsled]

They told me it was a stage 1 and there is no BOV and they didn't even offer 1 when I bought it and I explained to them that they really need to add them for 2 reasons 1 being a safety feature and 2 to eliminate back pressure turbine flutter and they told me it was unnecessary and then sure enough the next year low and behold, they took my advice and added it to the kit explaining to the customers exactly what i said to them! so i asked them if they could put 1 on for me and they want me to pay extra for it but they will weld the mounting bung on for free. One of the fellows down there told me that there is no way it is a stage 1 if it can produce that kind of boost and I gave him the part # from the ROTREX and it is a stage 1 compressor that for some reason works way better than most. he also didn't believe me about the boost # either but why on God's earth would I lie about it, I was simply trying to get some help from them to get this thing working smoothly without any issues and ended up spending a bunch more money with them and it still aint right! I got it down to 10-12 lbs and it runs great for the most part but in the most critical situation it fails and could ultimately get me killed. you get to the point where you add up whats been spent on this and the reality is shocking! 12000 dollars on the sled brand new after pay off then 5000 more for the kit and several hundred here and there you realize is this really worth it? I guess it could be if it worked properly because I love the sled but if I had it to do over again I would have to pass I won't have that kind of money again in my lifetime and with the cost of living here i may get to ride it twice this season. I would gladly trade the setup for a turbo kit! if anyone was interested in it.

 

[Barry Barton]

did u finally put a bov valve in and u said u have most of the pulleys they have u should contact matt at mpi and ask for the same pulley combantion as I have. U should also check your gems programer do u have a air hose going from the bottom of the air box to the gems and if u don't u will have trouble setting the sled. I missed this the first time I put the sc on the sled and noticed when I seen one at the skidoo show and I was missing the hose and once I hooked it up the sled was easy to set. I went outside today and tryed my sled started well but it was jumping up and down until it warmed up then it settled down. I'm taking the sled out this weekend and I'll let u know how it's running. u should call me we could probable find more things by talking. Turbo work ok but u have to be careful of the boost going up or down because more guys blow engines when they set the boost to high so their is good and bad for a turbo.

 

[pedsled]

Yes the GEMS hose is hooked up and it works but i just remembered that when you start it up and the gems cycles the LED's up and down a few time then sets at the bottom, that is the exact moment when it dies. then you start it up again and it will stay running. If i start it up and give it a little throttle it will stumble a bit at that exact moment but not die then I can go but I remember the old gems never had that problem ever until it went bad all together and the sled barely ran. The new gems can't get wet now as I have made a waterproof zipper case for it that is mounted right between the handlebars. Ya I guess I was getting frustrated and wanting to give up on it but I really love to ride it, and really its fine but the fuel thing on the top end of a long steep hill really has me worried now, and it does it every time!! it flat out acts like it ran out of gas, let off the throttle and grab a handful again and it comes back but its too late to recover and finish the climb.

 

[Barry Barton]

Ok but did u get that bov valve hooked up because it should help and have u tryed to burp the throttle half way up the climb . I think it might be the bov valve because if u are pulling to many psi that means u need more fuel so if u install a bov valve it will keep the psi under 10 and your fuel pump can keep up, I would check with mpi I think a stage 2 sc needs a bigger fuel pump to help with the fuel demand but i'm not sure. Darren phone number is 780-997-3818 he's the yamaha guy up hear.

 

[shawnmcgr]

If you don't have a air/fuel gauge I'd recommend the AEM. This will tell you if it's running out of fuel. Info is your friend. Are you getting lean pops? The more info you have about how your sled is running the better. I have not heard of stage I supercharger running out of fuel unless they were being run at low altitude. As your in Idaho I'm betting your at fairly high altitude so running out of fuel should not be a problem. But fuel pumps can go bad. You could also try reducing your boost. If it will run WOT for long pulls at 8psi but not 10psi then maybe lack of fuel is your problem.

I'd also recommend a BOV/By-pass valve. It helps keep your boost levels consistent which helps the sled run consistently.

The problem with your sled dying at start-up is normal. It's just the GEMS box cutting in after initialization. I just hold the rpms to 2000 for the 1st 15 secs then it's good.

The RPMs going up and down steady while it's idling likely means it's rich at idle. Adjusting down your altitude setting can help with this. The GEMS isn't exactly user friendly but it gets the job done. I think a lot of people under estimate how difficult it can be to properly set-up a fuel system, whether it's carbs on a mod 2smoke or EFI.

My fuel consumption isn't quite half what my stock sled was but it's close. I dropped from 120km/tank to 70. I think I can improve this as I'm rich in the 1st third throttle, which is where I'm running on the trail in and out. Also, if your going to make more hp you have to burn more fuel. Your going to pay to grin from ear to ear!

 

[pedsled]

The only gauge is the boost and it does in fact lean pop even when i adjust the GEMS rich. Could it be possible that the fuel pump is tired after 2000 miles? I run at about 6000-8500ft altitude I have no BOV or AEM I do have a wide band o2 sensor that i never installed. Ya i'm not too worried about the fuel consumption, Its worth the POWER!! I installed the kit at 1000 miles and ran it for 1000 miles it seems the fuel pump should have lasted longer than that. I guess I should get A BOV on there now and see if that helps. I can't afford everything at once.

 

[SCApex]

I also have an MPI Supecharged Apex, and i had that happen last year but I changed out all the relays and put a new battery in and now it seems way better, more response etc. I had a bad cell in the battery and well, it lagged, now it is all balls and i am running 6000-8500 ft. Let me know about the fuel system and if you find out anything. For now I am running 50/50 aviation fuel and supreme, and it rocks. New Apline 174 tunnel and M10 w/ Camoplast Extreme, let's see Friday how it rips!!

Cheers

 

[shawnmcgr]

Yup, sounds like your definitely lean. I've got 6500kms on my Apex with just wear and tear and breakage. Is the blue light on the GEMS coming on? Check your boost line to the GEMS to make sure it's getting a good boost signal (no leaks or kinks or ice slugs). If you have it mounted on your bars, it's possible to get moisture in the line then it freezes off and then there's no more boost signal to the GEMS. This happens with my boost gauge occassionally. I've got my GEMS mounted under the hood to keep it dry and warm. Could also be a plugged fuel filter. What settings are you maxing out? Red (main jet) and boost can be used to add fuel to full throttle. Increasing the altitude setting adds fuel to the entire curve, you could try that as well. Here's my GEMS settings for 8psi @ 5-7000ft (1,3,4,6,3,3.5). I've still got lots of room to add fuel at full throttle. You could also check your TPS readings to make sure it's giving the correct throttle position reading.

Couple freebees there to check.

good luck,

Shawn

 

[ridehard1212]

This does not have to do with OP orginal problem.. but what sort of AFR reading do you get?? Have a buddy running a stage 1 @ 5 psi 50/50 AV/94 chevron.. Sled orginally set up by Fastrax.. Only had it out once, ran really really good, low elevation(3-4000) and hard packed- to max 6inches of crust.. But sled was averaging mid 14s air fuel ratio.. and somtimes getting into the 15s.. this is to high? should be around 11.5-13?

Based on the low elevation i think that next time we go out we will play with the alltitude a bit and hopefully get the sled running a bit richer..

Thanks in advance Brandon

 

[shawnmcgr]

I ran an o2 sensor on my stock apex before installing the charger and it read 11.3 almost everywhere. Very consistent. So I generally shoot for 11.5 everywhere but especially at full throttle. I may see 12.5 at mid-range. If I see high 12's I'm getting nervous. MPI recommends do not ride with AFR above 13 @ faster than 30kph. you may see blips of high AFR as you get on and off the throttle, no biggy. But any steady throttle run should be below 13, I'd run below 12.5. Yup bumping up your altitude setting will help.

You o2 sensor could be hooped as well, Av gas has lead which kills your sensor. I'll get maybe 500kms out of one. $80 a piece at Mopac.

you should be good to 2000ft elevation on 94 octane @ 5psi. This'll help your o2 sensor last.

 

[Barry Barton]

hello again shawn tryed the sled this weekend didn't go that well clutching was way out have to reset it this week but my setting were .5,4, 3.5,6,3,5 talked to darren this week and he recomended that I keep mode 3 and 4 within 1 of each other and I should install a o2 senser. How hard is it to install a o2 sensor on the exhaust and how hard is it to set the sled up once u have the senser set up.

 

[powder muncher]

I will do mine tomorow. Just finnished the install and with the stainless bike pipe there is lots of space for the 02 sensor ( will be tight on a stocke exhaust)

I have done carbed turbo set ups with the air fuel and it makes it real easy.

Also need to get the clutching done. We wil see how it goes.

 

[pedsled]

As a matter of fact my TPS did fail me twice and both times it allows you to run out at WOT to get out so I gave her full pinch off then off the throttle all the way back and replaced it with a new one and set it to what my service manual said, I believe it was 19 on the low side and 99 on the high side but 20/100 was acceptable. Same problem with the new one then yamaha had a recall on all those and sent out a new improved one that hasn't failed thus far. I never did check my fuel filter so when I get it in the shop I will do so. The boost line to GEMS is fine and the blue light does come on and indicate the presence of boost. I will go out and get the sled in the shop and post the current GEMS settings. As far as my clutching goes, I was banging off the rev limiter constantly so this is what I did.... I got the lightest spring I could find, I think blue-pink-blue then the larger rollers and the heaviest weights yamaha had to offer with the heaviest rivets as well and installed them in all 3 holes with the addition of 2 washers in the center position, one on either side of the rivet for a grand total of 96 grams each. Comes in heavier than any aftermarket weight ramp I could find. I then geared up in the chaincase to the largest top gear Yamaha had to offer as well as the smallest bottom gear gear they had. This helped out dramatically but would still bang the rev limiter but not as bad. I haven't changed the secondary settings yet, i was going to loosen it up for a faster upshift and more load on the motor unless anyone has a better idea. I'm all ears and open to any suggestions on tuning tips. 6500-8500 ft elevation is where I'm running. The only other mod is the exhaust can, I took it off and removed the guts but I did that before i ever supercharged it. If I get the fuel thing figured out then I'm all smiles, it shreds hard!!! until it does that out of fuel BOG! Thanks for all you guys help so far, I'll keep you posted on what I find. Happy Holidays!

 

[powder muncher]

smaller rollers have more shift force --- if you hit the rev limmiter you need to go smaller not bigger.


Small changes are what you want to do clutching , if you do to much at the same time you will never know what did what.

 

[Barry Barton]

As a matter of fact my TPS did fail me twice and both times it allows you to run out at WOT to get out so I gave her full pinch off then off the throttle all the way back and replaced it with a new one and set it to what my service manual said, I believe it was 19 on the low side and 99 on the high side but 20/100 was acceptable. Same problem with the new one then yamaha had a recall on all those and sent out a new improved one that hasn't failed thus far. I never did check my fuel filter so when I get it in the shop I will do so. The boost line to GEMS is fine and the blue light does come on and indicate the presence of boost. I will go out and get the sled in the shop and post the current GEMS settings. As far as my clutching goes, I was banging off the rev limiter constantly so this is what I did.... I got the lightest spring I could find, I think blue-pink-blue then the larger rollers and the heaviest weights yamaha had to offer with the heaviest rivets as well and installed them in all 3 holes with the addition of 2 washers in the center position, one on either side of the rivet for a grand total of 96 grams each. Comes in heavier than any aftermarket weight ramp I could find. I then geared up in the chaincase to the largest top gear Yamaha had to offer as well as the smallest bottom gear gear they had. This helped out dramatically but would still bang the rev limiter but not as bad. I haven't changed the secondary settings yet, i was going to loosen it up for a faster upshift and more load on the motor unless anyone has a better idea. I'm all ears and open to any suggestions on tuning tips. 6500-8500 ft elevation is where I'm running. The only other mod is the exhaust can, I took it off and removed the guts but I did that before i ever supercharged it. If I get the fuel thing figured out then I'm all smiles, it shreds hard!!! until it does that out of fuel BOG! Thanks for all you guys help so far, I'll keep you posted on what I find. Happy Holidays!

I did the same on the primary but I was told to keep the revs between 10,000 and 10,500 on the motor by changing the weights because I ride the sled at 2,000ft at home.Then what I did is add a shockwave because the sled has a 45 degree helix on the stock sled and then all I have to do is turn the shockwave down to 43 to keep the revs between 10 and 10.5 when I go to higher elevation. With the gems I'm still learning so if u have any coments would greatly be welcome good luck

 

[pedsled]

My bad, Powder Muncher, You're absolutely right, I did switch to the smaller rollers from the stock ones but either way it still hits the rev limiter.