oil pump check valve flooded rear cylinders

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trappena
Posts: 65
Joined: Sat Nov 20, 2010 4:04 pm
Location: the Netherlands

oil pump check valve flooded rear cylinders

#1 Post by trappena » Sun Aug 27, 2017 3:52 pm

Guys,

What is the easiest way to get rid of excess two stroke oil out of the rear cylinders? Bike will not start because of hydro lock. Spend the whole day kicking the thing with the plugs removed but to no avail will lock almost immediately when you try to start it.

Regards

silverstrom
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Re: oil pump check valve flooded rear cylinders

#2 Post by silverstrom » Sun Aug 27, 2017 5:22 pm

You must have leaking carb float valves as well. I wouldn't be surprised if the petcock is shot too, or is it on prime? I don't think it's possible to leak enough oil past the check valves to hydraulic lock the cylinders. I had leaking check valves and it would leak 1/2 litre into the cylinders during winter storage. Less when sitting not being used over the summer. Fire the bike up and go for a ride and 20 minutes later no more oil in the pipes. If your pipes are as full as you say they are then you need to remove them and empty them out. If you don't empty them the cylinders will suck that oil and fuel into the cylinders on the down stroke. You'll never make any progress until the pipes are empty.

Did you do any work on the bike just before this problem started?

Don't underestimate the power of a hydraulic lock. It is easy to bend the rods while trying to kick it over if it is a hydraulic lock.

trappena
Posts: 65
Joined: Sat Nov 20, 2010 4:04 pm
Location: the Netherlands

Re: oil pump check valve flooded rear cylinders

#3 Post by trappena » Sun Aug 27, 2017 10:32 pm

silverstrom wrote:You must have leaking carb float valves as well. I wouldn't be surprised if the petcock is shot too, or is it on prime? I don't think it's possible to leak enough oil past the check valves to hydraulic lock the cylinders. I had leaking check valves and it would leak 1/2 litre into the cylinders during winter storage. Less when sitting not being used over the summer. Fire the bike up and go for a ride and 20 minutes later no more oil in the pipes. If your pipes are as full as you say they are then you need to remove them and empty them out. If you don't empty them the cylinders will suck that oil and fuel into the cylinders on the down stroke. You'll never make any progress until the pipes are empty.

Did you do any work on the bike just before this problem started?

Don't underestimate the power of a hydraulic lock. It is easy to bend the rods while trying to kick it over if it is a hydraulic lock.
It is a recently acquired bike, been sitting at least 6 years. Will start a rebuild thread shortly. Did remove the rear exhaust and emptied them, not much oil there. It seems that it pushes enough oil in the combustion chamber only when an attempt is made to start the bike. With the plugs removed it's not pumping it out. Petcock is ok, tank with it is off and not leaking.
Guess this engine has to come out, probably the rods are bend by now or the crank is out of whack (or both :sad: )

silverstrom
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Re: oil pump check valve flooded rear cylinders

#4 Post by silverstrom » Mon Aug 28, 2017 12:29 am

Six years of sitting if properly stored can cause many problems. Corroded bearings, rotted cylinders, etc. It can get ugly. I once spent a week trying to open an RZ350 engine that was improperly stored. It was like anything metal was welded together. Maybe you are just fighting against cylinder corrosion and stuck rings. I would consider that a best case scenario for now. It needs new crank seals so would need to be torn down anyway. Fingers crossed it is just a few minor issues working against you.

trappena
Posts: 65
Joined: Sat Nov 20, 2010 4:04 pm
Location: the Netherlands

Re: oil pump check valve flooded rear cylinders

#5 Post by trappena » Mon Aug 28, 2017 3:19 pm

silverstrom wrote:Six years of sitting if properly stored can cause many problems. Corroded bearings, rotted cylinders, etc. It can get ugly. I once spent a week trying to open an RZ350 engine that was improperly stored. It was like anything metal was welded together. Maybe you are just fighting against cylinder corrosion and stuck rings. I would consider that a best case scenario for now. It needs new crank seals so would need to be torn down anyway. Fingers crossed it is just a few minor issues working against you.
Storage area was not so bad, bike seems in pretty good nick except for the pool of oil sitting in the crank area. Haven't touched these engines in a few years and was reminded why I hate working on them :grin: I might remove the back cylinders to assess the damage and mop up the pool of oil. Last time I assembled the top end of an rz500 the engine was not in the frame. Is it even possible to only remove the back cylinders with the engine still in the frame?

BigGuy
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Re: oil pump check valve flooded rear cylinders

#6 Post by BigGuy » Mon Aug 28, 2017 9:59 pm

trappena wrote:
silverstrom wrote:Six years of sitting if properly stored can cause many problems. Corroded bearings, rotted cylinders, etc. It can get ugly. I once spent a week trying to open an RZ350 engine that was improperly stored. It was like anything metal was welded together. Maybe you are just fighting against cylinder corrosion and stuck rings. I would consider that a best case scenario for now. It needs new crank seals so would need to be torn down anyway. Fingers crossed it is just a few minor issues working against you.
Storage area was not so bad, bike seems in pretty good nick except for the pool of oil sitting in the crank area. Haven't touched these engines in a few years and was reminded why I hate working on them :grin: I might remove the back cylinders to assess the damage and mop up the pool of oil. Last time I assembled the top end of an rz500 the engine was not in the frame. Is it even possible to only remove the back cylinders with the engine still in the frame?
I think it is possible to remove them but as Silverstorm said the crank seals are most likely shot? A little bit of extra effort could save alot of $$$
Shake "N" Bake!

trappena
Posts: 65
Joined: Sat Nov 20, 2010 4:04 pm
Location: the Netherlands

Re: oil pump check valve flooded rear cylinders

#7 Post by trappena » Tue Aug 29, 2017 1:37 am

BigGuy wrote:
trappena wrote:
silverstrom wrote:Six years of sitting if properly stored can cause many problems. Corroded bearings, rotted cylinders, etc. It can get ugly. I once spent a week trying to open an RZ350 engine that was improperly stored. It was like anything metal was welded together. Maybe you are just fighting against cylinder corrosion and stuck rings. I would consider that a best case scenario for now. It needs new crank seals so would need to be torn down anyway. Fingers crossed it is just a few minor issues working against you.
Storage area was not so bad, bike seems in pretty good nick except for the pool of oil sitting in the crank area. Haven't touched these engines in a few years and was reminded why I hate working on them :grin: I might remove the back cylinders to assess the damage and mop up the pool of oil. Last time I assembled the top end of an rz500 the engine was not in the frame. Is it even possible to only remove the back cylinders with the engine still in the frame?
I think it is possible to remove them but as Silverstorm said the crank seals are most likely shot? A little bit of extra effort could save alot of $$$
Will remove the engine then next week for disassembly, no more cutting corners.

Regards

HWY9CA
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Re: oil pump check valve flooded rear cylinders

#8 Post by HWY9CA » Tue Aug 29, 2017 4:59 pm

I just fixed a bike that had almost a quart of 2t oil in the cylinder. No fuel all oil, YES it is possable to have a cylinder fill up with 2t oil.

To remove the oil;
remove pipe, hang upside down
Remove all spark plugs
put a rag in the exhaust port, rag over plug hole slowly crank by hand.
i used a compression tester hose and removed the valve in the hose- took a lot of cranks.
once no resistance, kick over slowly then faster [plug out of all holes].

It fired up - still had some oil in pipe, leaked out of pipe when it ran.

good luck
JT
http://www.rdsonly.com/
JT
1975 RD350B
1975 RD250B -rough
1979 RD400 Race bike- in process
1985 RZ500 - flame bike
1993 TZ250 4DP2- to be restored

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