Mikee
Newbie
- Joined
- Nov 18, 2015
- Messages
- 5
- Age
- 56
- Location
- Finland
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- Snowmobile
- Yamaha Nytro xtx mpi charged 220
Hey guys!
I'd need a little help. I have a Yamaha Nytro XTX 220hp MPI charged, year 2012.
The problem started when I updated from a 180hp kit to a 220hp kit. When the engine has run for about 2 minutes and I give it throttle so it goes over 4500 rpm and then release, the engine stays at 4200 rpm until I choke ISC-valve hose from pressure box.
Next thing I did was that I removed the ISC-valve hose from pressure box (inside diameter 12mm), choked it to 6mm and then placed a filter at the end of the hose. By doing this, the engine runs OK at mid-and high revs but idle rpm is only 1250-1300. Idle mixture is too lean and the engine don't run properly at idle.
Air/fuel ratio is 15-16 (recommendation is 13,8 to 14,5).
Any ideas how to fix this??
Another question is about the ISC-valve hose. When looking at the MPI installation picture you can see hose placed under the throttle body. In my charged kit the outlet for it is in the pressure-box. What is the correct place for it?
Thanks in advance!
//Mike from Finland
I'd need a little help. I have a Yamaha Nytro XTX 220hp MPI charged, year 2012.
The problem started when I updated from a 180hp kit to a 220hp kit. When the engine has run for about 2 minutes and I give it throttle so it goes over 4500 rpm and then release, the engine stays at 4200 rpm until I choke ISC-valve hose from pressure box.
Next thing I did was that I removed the ISC-valve hose from pressure box (inside diameter 12mm), choked it to 6mm and then placed a filter at the end of the hose. By doing this, the engine runs OK at mid-and high revs but idle rpm is only 1250-1300. Idle mixture is too lean and the engine don't run properly at idle.
Air/fuel ratio is 15-16 (recommendation is 13,8 to 14,5).
Any ideas how to fix this??
Another question is about the ISC-valve hose. When looking at the MPI installation picture you can see hose placed under the throttle body. In my charged kit the outlet for it is in the pressure-box. What is the correct place for it?
Thanks in advance!
//Mike from Finland
Attachments
mpi xtx
Extreme
Have you tried to ride the sled or just run it on a stand?
Did you replace the Blow off valve spring when doing this work?
Did you replace the Blow off valve spring when doing this work?
Mikee
Newbie
- Joined
- Nov 18, 2015
- Messages
- 5
- Age
- 56
- Location
- Finland
- Country
- Other
- Snowmobile
- Yamaha Nytro xtx mpi charged 220
Yes, I do have tried to ride it but the same problem is repeated.
I've also replaced the Blow off valve spring.
I've also replaced the Blow off valve spring.
mpi xtx
Extreme
I had a blow off valve spring that was too stong in mine and when I would let off the gas it would want to keep going, it felt like the throttle was stuck on but it wasnt. I would make sure that your BOV is working
ShafeNytro
Veteran
- Joined
- Nov 13, 2012
- Messages
- 35
- Location
- Wooster Ohio
- Country
- USA
- Snowmobile
- 2010 Yamaha Nytro XTX
- LOCATION
- Wooster
Mine is hooked into the intercooler. Never had an idle or wfo problem.
scuba_nytro
Veteran
- Joined
- Feb 1, 2011
- Messages
- 45
- Location
- Ontario
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- Canada
- Snowmobile
- 2009 Nytro RTX MPI Stage 1, Hindle Exhaust, Evolution Re-flashed ECU, Ulmer Clutch Kit, Split Rail Skis, etc.
I have an older Stage 1 MPI SC kit on my 09 Nytro and the IAC hose breathes to atmosphere with a filter on it as shown in your first picture. On newer MPI kits that hose is plumbed to the intercooler, not sure why the revision was made but it appears you have it connected correctly.
