Triumphrat

jsdc2005 · 10-03-2005, 10:41 AM

Hi,
I recently bought a used '03 T100. It is my first bike and I am just learning about both riding and maintenance.

Brought it in for inspection and the mech said the oil was overfilled, but didn't seem concerned. The oil filled the spy hole when the bike was vertical; mech said he liked either a bubble on the top or preferably, just halfway up the window. I later noticed a small amount of oil collecting on the top of the crankcase around the vertical hose (which I'm guessing is the crankcase breather). So I siphoned out about 12 ounces of oil. Now I see the oil again.

I am concerned about taking out too much oil - as people have noted, it's kinda hard to get an accurate read on that window. Any tips? Should I try taking out some more? I've read about Krank Vents - are they worth it? What's the right one for the Bonneville? I don't believe they help performance but maybe it would stop the oil seepage.

Thanks.

SpeedyPete · 10-03-2005, 11:47 AM

JS,

Several riders have commented that the oil sight glass is not overly helpful as an indicator of oil level. The best solution seems to be to drain the oil, refill it with the volume recommended in the service manual then just monitor it for leaks thereafter. If there are no drips and you can still see the oil at least 3/4 of the way up the glass, you're OK.

You might want to be careful about removing oil - you're probably better running too high than too low but I'll defer to better experts on this site for comment on that.

Pete

dawgfan · 10-03-2005, 01:06 PM

On the too low versus too high it is a fine line.

It is actually better to have a bit to little oil than to much oil.

Too much oil increases oil pressure inside the engine and adds stress to the seals. If the seals survive, all is good. If the added pressure from too much oil overtakes the seals, you have a problem.

TC

badrufus · 10-03-2005, 03:06 PM

Excess oil, in addition to the problem Dawgfan describes, usually ends up in your airbox, because that's where the oil breather exits. If it's just a bit, it will sit in the bottom of the box; a bit more and it will drain into the little clear oil catch at the bottom of the box; more than that and you've got a real mess in your airbox. I haven't found any problem using the sight glass. I put the bike on the centerstand in the same place in the garage, let it drain overnight, and check it in the morning. It just sits at the three-quarter mark, because this lovely engine burns no oil. Such a change from the last Yamaha I had, which burned 12 ounces of oil every 1000 miles, and that was within spec! I think a key to using the sight glass is having a centerstand, otherwise it is pretty hard to hold the bike level and look at the glass without altering the angle of the bike.