Dip Stick Dirt...YZ450F

Why did Yamaha put the dip stick there?:ride: Anyway, went to check the oil before a ride and when I took out the dip stick there was dirt in the recess above the threads (The bike was clean so I didn't check it with a big clump of dirt there, FYI, so not sure why or how the dirt got there :ride: ). I cleaned out the dirt carefully but wonder if some dirt fell into that area, tank, resevoir (not sure of the name).

Normally I would just change the oil and filter however I also have the other common problem (about 50 threads on TT about this) of the oil drain cover bolt stripped. Well, its not completely done yet but I fear the next time I take it out it will be toast. So I was hoping I could ride :ride: one more time before taking and having a time cert put in.

My question is, if dirt (very small amount if any) got into the that area (tank I guess), is it critical? I am not sure about the oil flow path, does that oil go to the filter from there? What do you think?

They put it there because that's where the oil tank is. :ride:

One of the first things I did to mine was to take a sheet of light plastic and cut out a mud/stone shield for the front of the frame, above the skid plate, leaving it over hang slightly on the left side in front of the dip stick. That helps.

The oil flow is:

Tank to feed pump, to oil filter, to lube points.

From there it drains to the sump, goes to the scavenging, or return, pump, and back to the tank. The oil filter is a full flow design, so all oil coming from the pump is filtered. If you are very worried about it, you could simply warm up some oil in a pan of water and pour it directly into the tank with the tank drain removed. That will wash stuff straight through and out.

On the filter bolt, get a 6x1.0mm tap and die for your tool box. Chase out the threads both on the bolt and in the cover (grease the tap to retain the chips). You may also want to buy a new lower bolt, chase the threads, and use that. It may work for quite a while longer.

Don't follow the manual procedure for draining the oil filter well. The lower bolt has a hole cross drilled into its threads through which oil from the well flows when the bolt is removed. Because this oil is rich in metal debris, that debris ends up in the threads, and damages them when the bolt is replaced. Because of this, I recommend that you remove the top two bolts first, then the bottom one, and allow the filter well to drain to the outside, minimizing the amount of oil flowing through these sensitive threads.

grayracer, thanks! I knew I was going to get that answer to the location of the dip stick..ha ha. I had an 03 and that location was nice up on the frame where you could actually check it anytime! To your other point, I actually bought a thread tap yesterday to do just what you said before I take for a time cert, hopefully that works. OK, so I might just wash it out like you say but I should probably be ok because the filter should catch it. THANKS!

If you flush it, be sure not to miss the point that you want to pour the oil in through the dip stick hole, not the filler cap, so that it goes straight through the tank and out with involving the rest of the system.

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