Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Honda VTR 250 2001 engine question

Discussion in 'Technical and Troubleshooting Torque' started by RgnHpr, May 24, 2014.

  1. Hey team!

    This is my first post. Great to be here!

    Just a quick question about Honda VTR 250 engine types, if a anyone is in the know.

    I've just done an engine swap in my 98 Honda VTR, as the first engine had a blown head gasket. The new engine is a bit newer, from a 2001 bike.

    All is looking good, aside from two extra pipes that come off the top of the valve covers for each cylinder. They look as though they might be breather lines, as when the engine is idling they make it quite loud, unless blocked up.

    Just wondering if anyone knows what these two extra outlets might be and where they should lead to? Can get some photos if anyone is keen to help out.

    Thanks all!
  2. Can you take a photo?
  3. Cheers for getting back to me Bjpitt, My apologies for the average photos. It's dark here and I had to make do with my headlamp. Hope you get an idea. If not, I can suss some more in the day light tomorrow.

    [​IMG] [​IMG]
  4. It's got me stumped, the service manual I have for a 98-07 VTR doesn't mention them. Hopefully someone with the same year engine can take a look. I think you are right, and maybe they lead back to the airbox?
  5. they are PCV system. Positive Crankcase Ventilation.

    blowby gases must find way to escape from engine and it was used to be a just a vent line to the atmosphere.

    after emission issue had been raised, manufactures put PCV system in the engine.

    those lines came from your cranckcase, and to the intake system for recirculation and re-burn the blowby gases.
  6. Thanks so much for that guys! Really appreciate your help.

    Do you think that the emissions need to run through the valve that's been mentioned above, or would we be OK to just run them up to the airbox directly?
  7. If Honda could have avoided putting a part into the system then they would have. My guess is you need it, to avoid induction vacuum problems.
  8. Hmmm, very fair point Bumblebee. I will get in touch with the guy who sold me the engine and see if I can get some advice.

    I wonder if I'll need to get some newer carbs etc too, as I'm not sure the '98 carbs or other parts would have the right vacuum line to support this new part...??
  9. PCV lines go straight to airbox
  10. Cool, do you have your VTR set up like that dmrmgl?

    Just concerned I'm going to do damage by plumbing them up incorrectly.

  11. Yep. My VTR set up is same as yours:)