Topic: oil pump sealing woes-advice needed.

[davesee]

i've been working hard at tackling everything that seals under the chain cover in an attempt to stop little whisps of oil from getting on my back tire of my 1980 cb650, which i find pretty unsettling.

i cleaned the whole area up, and it really seems like my oil pump was the main culprit (i band aided my now discontinued sprocket seal with a healthy dose of threebond and it's little drip has stopped for the time being). oil was coming out at a pretty good clip from around the pump, so i took the pump off and had a go at replacing the seals. here's where things have gotten tricky...

honda no longer supplies the 46x3mm seal, so i picked up a 46x2mm (didn't work) and a 45.5x2.5mm (also leaked). i found an o ring kit that seemed to have an exact match for the original 46x3mm seal, so i put that in, and also replaced the o ring that goes to the pressure sensor with a similar sized one from the kit. the two other o rings on the pump i replaced with new honda ones.

the current seals from the kit failed after about 80 miles of riding. well, they failed after about 70 miles and i rode with oil SOAKING my back wheel for 10 miles until i saw my girlfriend frantically waving at me in the rearview mirror from her bike. there was so much oil loss and so much oil everywhere that i rode home in the back of the tow truck.

is there a threebond or silicone sealant that will fill the gaps with these o-rings and is appropriate for use in this application? am i not re-installing  the pump on tight enough? i've got some bike tripping planned for my vacation this weekend, and i'd love to get it leak free.

[70CB750]

Did you talk to Rocket Seals?

http://www.rocketseals.com/catalog/o-rings-and-seals-for-metric-measurements/metric-o-rings/metric-o-rings-cross-section-3mm-3-9mm%3B32426

[phil71]

whenever there's a pump seal (the kind with the spring around the lip) you can usually find a plumbing supply house that will have them. Just take the old one to be measured and don't say the word "motorcycle"

[davesee]

70cb750: thanks for that. it looks like they have a possible replacement for the sprocket seal as well, if i can figure which type of seal it is from their diagrams. of course, it's not gonna help me for my vacation .  like i said, however, the main o ring i used seems to be identical in size to the original according to my measurements and calibrated eye. the smaller one is a little more doubtful, and rocket seals doesn't carry an exact one of those either, but it looks like they can get pretty close.

phil71: my pump doesn't specify a seal with a spring like the sprocket seal, just plain ol' o rings.

[scunny]

I just took my pump and the specs to a local seal distributor and he matched them. should have kept the size list.