Loosing Boost?

[162 Wizzy]

Calling all Turbo experts.
I run a 2008 Nytro with a MCX 270 rear mount kit. I was running in Chappel yesterday. Running like a champ then it started to fall on its face. When i wicked the throttle the boost would momentarily spike up then drop to zero.
Once again from a dead stop on the lake it would stand up then just as fast fall off.
Other than the boost issue i ran it outta there no problem. I'm no mechanic but i assume the intercooler has somehow become detached or i have a hose cut or leaking.
Anyone have any idea what else it would be or am i on the right track here. Looks like a fairly big job to rip all that out of there. Might be a job for the ticketed guys.

 

[SLY]

Sounds like a leak to me, a pretty big one. had you had previos issies with losing boost?

 

[162 Wizzy]

This sled has never even so much as hickuped. Nothing visible. Intercooler seems to be solid so I'm guessing something has come off the back side.

 

[mclean]

spray soapy water on the boots (the rubber peices that connected the piping to the intercooler)...or spray soapy water on all the connections i suppose, watch for bubbles

 

[MRFUSION]

Seen this before with customers, unplug the wires to the aux injectors in the intercooler and try it. I have had control box issues where the wires plug into the box or come apart at the plug. Check all boost lines and wiring, intercooler boots and then maybe send out the control box. Shad

 

[overkill131313]

I have a problem with loosing boost at 7000 feet......I can get 15 PSI but at around 5000 and down I can make 25 PSI.......yes I know that is to much lol.......I turn my adjustable boost controller right out when up top but then I have to close it when going down the hill or I get 25 PSI........I used to get 18 PSI up top??????? WTF? what do I look for?

 

[suzuki_ryder]

Usually if you lose boost suddenly, it mean your air filter is blocked with ice.

 

[162 Wizzy]

All good stuff guys, thanks but i think I'm taking it into Slave Lake Yamaha. Don't have the time to work on it plus those fellas know thee MCX stuff.
I will report back on the findings.

 

[sledslut]

a quick check to see if its an exhaust leak.. turn the sled on cover the exhaust..

i just had to replace my exhaust gaskets in mine., had a bad leake.. the gaskes just burnt out. the other can it can be is a crakced exhaust.. thats happened to me too..

your boost tube from under the tunnel can possablely be off. list goes on..

but your loosing air pressure somehwere.

 

[overkill131313]

a quick check to see if its an exhaust leak.. turn the sled on cover the exhaust..

i just had to replace my exhaust gaskets in mine., had a bad leake.. the gaskes just burnt out. the other can it can be is a crakced exhaust.. thats happened to me too..

your boost tube from under the tunnel can possablely be off. list goes on..

but your loosing air pressure somehwere.

no exhaust leaks.....went throught entire exhaust system last month......if I plug off the exhaust it will all most stall......Im scart it will blow a gasket if I keep it plugged........I need to find a new liquid filled boost gauge......hard to see what it is really pulling.......but I know if I leave the boost controler set where it is.....my boost is too hight down at the house (2000) and at the top it is alot lower......

 

[modmanmike]

no exhaust leaks.....went throught entire exhaust system last month......if I plug off the exhaust it will all most stall......Im scart it will blow a gasket if I keep it plugged........I need to find a new liquid filled boost gauge......hard to see what it is really pulling.......but I know if I leave the boost controler set where it is.....my boost is too hight down at the house (2000) and at the top it is alot lower......

Are you losing all your boost? your using a manual controller. it wont do any compensating for you. You can get the dial taken out and the get it set to what you want it and let it do the compensating for you. also you can adjust the dial somehow. Im not sure how. Talk to SLY on here. he did mine. When I first had my turbo set up I could crank my boost dial in all the way and it would only make 12 pounds. he would know what you need to do. they adjusted mine so I can only go down to 8 psi but I can crank it up as high as I want.

 

[overkill131313]

Are you losing all your boost? your using a manual controller. it wont do any compensating for you. You can get the dial taken out and the get it set to what you want it and let it do the compensating for you. also you can adjust the dial somehow. Im not sure how. Talk to SLY on here. he did mine. When I first had my turbo set up I could crank my boost dial in all the way and it would only make 12 pounds. he would know what you need to do. they adjusted mine so I can only go down to 8 psi but I can crank it up as high as I want.

when I turn mine all the way in......10 PSI
when I turn it out to where it dont climb any more at 6-7000 feet it goes to 15 PSI
if I drive down the hill and dont touch the controler it will it 25 PSI......

my question is why wont it make 18 plus up at the top of the hill?????

 

[JDen]

I have a problem with loosing boost at 7000 feet......I can get 15 PSI but at around 5000 and down I can make 25 PSI.......yes I know that is to much lol.......I turn my adjustable boost controller right out when up top but then I have to close it when going down the hill or I get 25 PSI........I used to get 18 PSI up top??????? WTF? what do I look for?

I am having the exact same problem with a 270 mcx on my 2010 nytro.

 

[overkill131313]

I am having the exact same problem with a 270 mcx on my 2010 nytro.

some one should have an answer for us! if I could run higher boost than 18 PSI and keep it together I would........15 just dont cut it lol! down low does that 25 ever pull hard lol. just did a few half throttle blurps.....what a feeling!

 

[JDen]

I know what you mean, mine was around 23 or so when I came home, I thought I had it set to not wheelie! Wrong! Would be nice to figure this out though. Mines makin about 16 at 6000 ft and 23/24 at 2200 ft.

 

[overkill131313]

I know the air is thinner up at 7000 feet but I used to make 18 PSI......the turbo should be easier to spin at higher elevations....but it has to spin faster to get more air in..........but what has changed to make the PSI drop.

 

[162 Wizzy]

A little follow up for ya. Got the Nytro back from Slave Lake Yamaha today. It was a head scratcher but Tapex figured it out. Bad fuel pump. Wasn't allowing enough fuel to supply the other injectors causing it to fall on its face.
The scary part was how lean the sled was running for that short time.
Time to install an air-fuel guage.
Thanks again to the boys at Slave Lake Yamaha!:d

 

[JDen]

I know the air is thinner up at 7000 feet but I used to make 18 PSI......the turbo should be easier to spin at higher elevations....but it has to spin faster to get more air in..........but what has changed to make the PSI drop.

Just FYI....I had a hose off of the back of my intercooler, hooked it back up, zip-tied it back on, and everything seems better. Rode Revelstoke this past weekend and set it to 17 psi and it ran right there the whole weekend.

 

[NM]

Just FYI....I had a hose off of the back of my intercooler, hooked it back up, zip-tied it back on, and everything seems better. Rode Revelstoke this past weekend and set it to 17 psi and it ran right there the whole weekend.

That would be the idle air hose. When you spiked the boost, it would have blown it off. That is the risk with these sleds when people wack the throttle at low elevation...it is very easy to blow a line apart, break a vac T, or blow a line off. It is no coincidence they run worse after a big boost spike.

NM

 

[overkill131313]

I found the problem........I have two 2 inch long lines going from the top of my intercooler to the fuel regulator........one was toast.......I replaced both and what a different feeling........I love when I have no turbo lag.....with in 3 feet I'm on full boost and had to turn it down.....havent gone up the hill but I'm 100% sure this was the problem........no leaks now........thanks for the head up! did even think about looking at the small hoses.