Oil drip

[richclarke]

I’m getting a tiny (but frustrating) oil drip from under my1980 RD350LC.
I had it before and identified the o-ring on the spigot in the RH crankcase cover that separates the cooling circuit from the gearbox oil. I’ve changed that... and the gearchange shaft and oil seal but still the drip persists.
Any ideas?
Rich

[copper99]

Is it 2 stroke oil ....or gearbox oil? If its 2T oil it can be down to the check valves failing in the oil pump..

[stusco]

It has been mentioned before sometimes it’s a plug in the crankcase it just needs tapped back in

[richclarke]

Dec 18, 2018 11:06:36 GMT 1 copper99 said:

Is it 2 stroke oil ....or gearbox oil? If its 2T oil it can be down to the check valves failing in the oil pump..

I think it’s gearbox oil given its viscosity and colour.

[richclarke]

Dec 19, 2018 8:35:28 GMT 1 stusco said:

It has been mentioned before sometimes it’s a plug in the crankcase it just needs tapped back in

I’m sorry. I don’t know about this plug you mentioned? I’ve looked at the Haynes manual and can’t seem to identify it. Any more info?

Cheers

Rich

[marsbar350]

its by the front sprocket a round plug maybe 10mm dia
that sometimes loosens
or the gearbox sprocket seal is leaking

have a look here rdlccrazy.proboards.com/thread/27382/4l0-crankcase-plugs

[rigga]

Neutral switch?

[richclarke]

Dec 19, 2018 12:26:39 GMT 1 marsbar350 said:

its by the front sprocket a round plug maybe 10mm dia
that sometimes loosens
or the gearbox sprocket seal is leaking

have a look here rdlccrazy.proboards.com/thread/27382/4l0-crankcase-plugs

Excellent. Thank you. I’ll have a look.

[richclarke]

Dec 19, 2018 13:47:05 GMT 1 rigga said:

Neutral switch?

The neutral switch was cracked when I bought the bike, so I changed it for a new one. It’s no longer leaking from there.

Cheers

Rich

[richclarke]

Found the bugger!

The two lower bolts for the RH inlet were stripped and not holding the inlet to the barrels properly. A quick call for a helicoil or two and it’s all good to go.

Rich

[doohanno1]

Dec 19, 2018 8:35:28 GMT 1 stusco said:

It has been mentioned before sometimes it’s a plug in the crankcase it just needs tapped back in

Why is that plug there in the first place.?
Could be a little dangerous if anything.!!

[kostas]

Jan 8, 2019 21:58:30 GMT 1 doohanno1 said:

Dec 19, 2018 8:35:28 GMT 1 stusco said:

It has been mentioned before sometimes it’s a plug in the crankcase it just needs tapped back in

Why is that plug there in the first place.?
Could be a little dangerous if anything.!!

The gearbox shift fork shaft goes thru the hole before the ally plug is fitted.

[JonW]

The plug is there as the shaft hole was drilled through the case.

Its not dangerous as they stay in with friction for tens of years without compliant. A gentle tap fixes the problem. Gotta love that.

[dusty350]

On the aircooled Rd's the plug was a rubber seal (2) and they did weep after a time. The ally plug in the Lc's and Pv's rarely give trouble

Dusty

[marrcel]

I think your rh oilline is syphoning. So after the helicol repair there will be less oil on the ground. But more in your crankcase.
Take the oil line loose and check how many drops in 24h wil fall in an emty jar. It should not dripp.

[shaunyb63]

I had the very same problem with mine, the oil pump check valve on the left side was faulty which was causing mine to leak, so pulled oil pipe off from left carb and after a couple of days i had a small pool of 2stroke oil,even though engine had never been started, sent pump to arrow for refurb and now problem solved .
When mine leaked the oil would drop through the drain channel on top crankcase and collect on the left lower crankcase nut making it look like the oil was leaking from that point .
Shaun.

[richclarke]

Jan 9, 2019 16:51:23 GMT 1 marrcel said:

I think your rh oilline is syphoning. So after the helicol repair there will be less oil on the ground. But more in your crankcase.
Take the oil line loose and check how many drops in 24h wil fall in an emty jar. It should not dripp.

Excellent advice, I’ll do that.

Many thanks

Rich

[richclarke]

Jan 9, 2019 17:29:20 GMT 1 shaunyb63 said:

I had the very same problem with mine, the oil pump check valve on the left side was faulty which was causing mine to leak, so pulled oil pipe off from left carb and after a couple of days i had a small pool of 2stroke oil,even though engine had never been started, sent pump to arrow for refurb and now problem solved .
When mine leaked the oil would drop through the drain channel on top crankcase and collect on the left lower crankcase nut making it look like the oil was leaking from that point .
Shaun.

That is exactly what is happening. I’ll test it to see if it’s syphoning and if that’s confirmed, I’ll whip the pump off and send it to Arrow for refurbishment.

Thanks for your help and advice.

Rich

[arrow]

Rich, you WILL get a leak if the bolts are not clamping down properly, due to a certain amount of blow back (even with the reeds) this is why inside the airbox has a smell of fuel.
That being said, the check valves can pass at anytime if even the slightest of debris get on the seats, from any source.

I edited the post, I thought you were richclair at first, I've done his pump but not yours.
Is the bike a heavy smoker on one or both sides when you first start it up after it's been standing for a week or two? Then once warmed up on the road, the smoke goes pretty normal? If so then quite possibly check valves in the oil pump, as the lads have stated.

[richclarke]

Jan 10, 2019 14:17:47 GMT 1 arrow said:

Rich, you WILL get a leak if the bolts are not clamping down properly, due to a certain amount of blow back (even with the reeds) this is why inside the airbox has a smell of fuel.
That being said, the check valves can pass at anytime if even the slightest of debris get on the seats, from any source.

I edited the post, I thought you were richclair at first, I've done his pump but not yours.
Is the bike a heavy smoker on one or both sides when you first start it up after it's been standing for a week or two? Then once warmed up on the road, the smoke goes pretty normal? If so then quite possibly check valves in the oil pump, as the lads have stated.

Thanks Arrow.
I’ll do the syphon test over the weekend and see what’s what. If the pump needs refurbishment I’ll send it over to you.
Can you DM me the costs, where to send it to etc?
Cheers
Rich (The other one)

[arrow]

Will do Rich.
It's not the syphon principle, simply gravity feed due to the height of the oil tank.

[marrcel]

Hello Garry
your right about gravity. But why it is often named syphoning?
That is because the feed line and the pump are lower than the connection at the carbs.
Correct me if i am wrong.

[arrow]

Jan 11, 2019 13:38:47 GMT 1 marrcel said:

Hello Garry
your right about gravity. But why it is often named syphoning?
That is because the feed line and the pump are lower than the connection at the carbs.
Correct me if i am wrong.

Correct. Syphoning is different.

[richclarke]

Jan 11, 2019 13:55:56 GMT 1 arrow said:

Jan 11, 2019 13:38:47 GMT 1 marrcel said:

Hello Garry
your right about gravity. But why it is often named syphoning?
That is because the feed line and the pump are lower than the connection at the carbs.
Correct me if i am wrong.

Correct. Syphoning is different.

Noted thanks.
Gravity not syphoning.

Rich

[arrow]

Carbs. Are still lower than tank. If one part of the pipe work goes above the level of the feed in the tank, then it's syphoning.