[rodH]

I was working on my 2005 CRF450R last night (installing larger tank and radiators, more on this in another thread) and I remember that the last time I rode, it was pretty hard to start cold (after it was warmed up, one kick every time). So I wanted to see if that was a fluke, so before working on it, I tried to start it again. Turn on gas and choke, 3-4 throttle blips and tried to kick. No go. Finally took me probably 15 kicks to start it. Something isn't right, because when I got it out of storage 5 months ago, after it sat for a couple years, It started on the 4th kick, no problem. Same with the next few rides.

As I was working on the bike, I noticed that the breather hose was completely black (full of oil). I remember reading something a while ago about how they can fill up with oil and if this happens, it can make it extremely difficult or impossible to cold start (I can't find the thread now). I unplugged it and quit a bit of oil came out. I tried to do an extensive search last night, but it is really hard to find much info on this. I have read that the hose can fill up if you over fill the engine oil (sure enough, my window was full of oil, so I must have over filled it, I guess. I also read that if you lay the bike down while it is running, it can cause the oil to overfill into the hose. I did have a crash where I laid it down and it ran for a bit (rekluse let it keep running). This ride, the bike was easy to start, since this ride, it has been difficult to start. So it may have filled up from overfilling the engine oil and/or laying the bike down.

Sounds like many people are just leaving this valve open or putting some foam at the tip or buying the tokyo mods or applied kits, or even doing DIY solutions with a small filter at the end (allowing oil to seep out but not letting junk in).

I am still not done with working on the bike, so I haven't been able to just drain the oil out of the tube and let it cool and then attempt to cold start again. I guess my question is, what is this hose for and is this really a common issue that makes it hard to start the bike when it is cold?

TIA

[Aussiecrf230]

Have always split the pipe in half for about and inch and a half so less chance of getting clogged.

One of those items along with carb breathers that needs to be checked when cleaning or after storing for a while.

[rodH]

Have always split the pipe in half for about and inch and a half so less chance of getting clogged.

One of those items along with carb breathers that needs to be checked when cleaning or after storing for a while.

Great. Thx