Warm idle problem

[YamahaRyan]

When nytro is cold it idles great, when you take a ride it wont idle when warm. I had it in the garage and changed the plugs and started it and it would not idle in the heated garage. No codes are in the diagnostic system either. I have installed an exhaust and that's it, no pc5 or anything else.

 

[YamahaRyan]

So finally today the compression test was low. Each cylinder was around 170 psi. The leak down test was around 20% per cylinder. The engine does not smoke any and it seems to run awesome. We have the sled not overheating anymore as well. Could the tests be low because of sitting for over a year and just be dirty or is there a serious motor problem starting. Any help would be appreciated.

 

[herndonp]

Sounds like a vacuum leak. Have you checked all your tubing on your intakes? Checked intake connectors (loose or leaking)?

Pete

 

[herndonp]

Read this thread http://www.ty4stroke.com/threads/compression-test-results.108674/

Pete

 

[YamahaRyan]

Thanks herndonp. I have had all the tests done at Yamaha shop so far but I am going to be picking the sled up soon. My friend thinks we should pull the head and have I redone as this will have to happen anyways and then we can see into the cylinders and see if they are scored. We are kinda leaning toward the valves maybe sticking but not exactly sure. I feel the nytro has been overheated in the past and now I get to deal with it. I am going to make this beast work somehow, been hoping to hear from grizz as he maybe a big help as he lives close to me. All the advice is good as I am not very mechanical and work a lot.

 

[herndonp]

Well wish you the best. Let us know what you find.

Pete