[Rokrover]

It is good policy to periodically replace the orange O-ring sealing the oil dipstick to the fill hole. I never worried about using a new one until grit had accumulated around the fill hole and my original fell off during routine inspection.

Even worse - there are reports over on the Bolt forum these can actually drop into the crankcase if you don’t pay attention! Not just any O-ring will do either, as the material has to be high temperature and oil resistant. Yamaha’s P.No. is 93210-27370-00 and at $2.70 it’s cheap insurance.

 

[eddie]

Good idea!
After dealing with these at the shop, I wonder how many get lost.
Even new O-rings don't stay on the dipstick very well.
I can picture one slipping down along the fatter part of the dipstick as one goes to put the stick back. The o-ring then can get caught and pushed into the crankcase.
One just needs to be mindful of how it's going until the dipstick is almost all the way in.

 

[Rokrover]

Even new O-rings don't stay on the dipstick very well.
One just needs to be mindful of how it's going until the dipstick is almost all the way in.

The dipstick uses a special 26x3 metric thread and the O-ring is “captive” in a shallow channel under the head. I tried a more sturdy flat washer but really only a compressible O-ring will work. It’s not the best design as even a fresh O-ring will slip out easily.

So, as Eddie notes - be vigilant checking / adding oil and keep a finger under the O-ring to hold it in place. Maybe that’s why Yamaha made it high-visibility orange?

 

[YamiGuy]

That might be why, its just too bad that car makers and bike makers don't tell you this stuff, its always discovered through experience and observation. One of the reasons why I like owning slightly older bikes

 

[eddie]

It could be worse. Honda, in it's infinite occasional weirdness, decided that Americans like to check the oil in a bike with a dipstick.
So, for the then-new 1991 CB750 Nighthawk, they designed out(!) the source bike's sight glass in the clutch cover and put in a dipstick.

Since they were cost-cutting and had removed the CBX750's shaft drive, hydraulic clutch actuation and center stand (among other things),
they put a plastic cap in the existing dipstick hole on the left with "DON'T OPEN" on it.

I bought one of the 1st 91's and was befuddled every time I checked the oil. I had to balance the bike up off the side stand while I stood
on the right side of the bike. Then I had to take one hand off the bike, unscrew the dipstick, remove it, wipe it off, reinsert it without screwing it in,
remove it once more, inspect the oil level and then put it back again. All of that was accomplished while balancing the bike upright with a hand and a knee,
hoping I didn't put the bike back on the side stand wrong when done and drop the bike.
First Hondaline accessories ordered? Case guards and a center stand!

 

[OpenRoad]

Such a pain to get the o-ring out if it falls into the crankcase. Gotta drain the oil, remove all the bolts, maybe a new gasket.

 

[TheScrambled]

All motorcycle manufacturers should just install a sight glass so we don't have to deal with dipsticks anymore. I can see the merit in a car with how the cluttered and enclosed the engine bay is.

 

[YamiGuy]

in the future they could always make it digital just like cars that way we can look at one screen to read about most things bike health related, smartest thing to do since bikes have always lacked in that area.

 

[flatrack]

Yeah for sure! Everything on a motorcycle should be digital! Oil level, oil temp, oil pressure, tire pressure, air temp, wind speed and direction, gps, abs, traction control, backup camera... in all honesty we don't need the motorcycle. The whole riding experience could be thoroughly and safely enjoyed via virtual reality. Don't even have to leave the house.

 

[eddie]

Yeah for sure! Everything on a motorcycle should be digital! Oil level, oil temp, oil pressure, tire pressure, air temp, wind speed and direction, gps, abs, traction control, backup camera... in all honesty we don't need the motorcycle. The whole riding experience could be thoroughly and safely enjoyed via virtual reality. Don't even have to leave the house.

I'm just happy I don't have to set breaker points any more.
One car and one motorcycle in a lifetime with those was enough.
:grin2:

 

[OpenRoad]

Well if we're talking about the hay days, I'm just glad I don't have to kick start the bikes anymore. That was a pain every time.
We don't need to digitize everything, but a small window for oil levels isn't asking for too much.

 

[flatrack]

I'm just happy I don't have to set breaker points any more.
One car and one motorcycle in a lifetime with those was enough.
:grin2:

Wow, I'm guessing you havent owned many cars. Dont get me wrong, I appreciate EFI, but the heydays of point files, thickness gauges, and timing lights, man those were some good times. Remember messing around with jets - trial and error after installing that shiny Kerker? And the kickstarter? C'mon that's the coolest! I want simplicity, hence the BOLT, just wish it had a kicker.

 

[eddie]

Wow, I'm guessing you havent owned many cars. Dont get me wrong, I appreciate EFI, but the heydays of point files, thickness gauges, and timing lights, man those were some good times. Remember messing around with jets - trial and error after installing that shiny Kerker? And the kickstarter? C'mon that's the coolest! I want simplicity, hence the BOLT, just wish it had a kicker.

Yep, I have had several EFI cars & trucks, but just one non-HEI 1974 Oldsmobile Cutlass/350 4bbl that I drove for 13 years. I had a little tool box with a dwell/tach meter and a timing light in the trunk. When the neighbor's kids would come watch me work on it, I'd clip the pickup to the timing light around the coil wire and pretend to "shoot" them with the "ray gun". LOL
My 1st bike was a early 70's CL350 Honda. Didn't buy my first f.i. bike until 2002. Still have several boxes of jets, needles, etc... around here somewhere.

 

[OpenRoad]

Seeing classic cars like those makes me wish I was old enough to drive when they were still being produced. A well maintained one looks like a classic beauty these days. Same with bikes and I can see why some people like collecting classics.

 

[Rokrover]

If I may drag this thread back on track, it seems Yamaha recognized a problem and redesigned the original O-ring. The new part number is 93210-27778-00 and the O-ring is now black. The only difference I can measure is a slight increase in thickness from 2.35 to 2.40 mm and decrease in outer diameter from 33 to 32 mm. The new O-ring seems to sit snugger in the dipstick groove and time will tell if it falls out so readily. The original orange O-ring is below the dipstick in the attached picture.

 

[flatrack]

Yep, I have had several EFI cars & trucks, but just one non-HEI 1974 Oldsmobile Cutlass/350 4bbl that I drove for 13 years. I had a little tool box with a dwell/tach meter and a timing light in the trunk. When the neighbor's kids would come watch me work on it, I'd clip the pickup to the timing light around the coil wire and pretend to "shoot" them with the "ray gun". LOL
My 1st bike was a early 70's CL350 Honda. Didn't buy my first f.i. bike until 2002. Still have several boxes of jets, needles, etc... around here somewhere.

Oh ya, there's a classic! Nice car! And your CL350 has to be one of the coolest first bikes ever. The vintage street tracker/scrambler market is very hot these days. There's a 1972 CL350 on Ebay right now for $5000! Man it wasn't that long ago you could pick that stuff up for next to nothing!

 

[OpenRoad]

Thanks for the part number Rokrover! Better safe than sorry and o-rings are pretty cheap anyways, so may as well replace the existing one.

 

[Cruze]

If I may drag this thread back on track, it seems Yamaha recognized a problem and redesigned the original O-ring. The new part number is 93210-27778-00 and the O-ring is now black. The only difference I can measure is a slight increase in thickness from 2.35 to 2.40 mm and decrease in outer diameter from 33 to 32 mm. The new O-ring seems to sit snugger in the dipstick groove and time will tell if it falls out so readily. The original orange O-ring is below the dipstick in the attached picture.

Thanks for the info! Be sure to keep us updated on how it works out though, hopefully it solves the issue.

 

[Khauff]

Hi

Can anyone tell me thread pitch on the oil dipstick and measure the length of the rod?

Thanks

 

[Schu]

Hi

Can anyone tell me thread pitch on the oil dipstick and measure the length of the rod?

Thanks

The length is 8.38 inches from the o-ring seal face to the end of the stick.

I have no idea what the thread pitch is. It measures approx 26-27mm OD and it appears there are about 4 threads over a span of 12mm. Maybe you can determine it from that....maybe not.