Oil behind timing cover?

[bellison80]

So this bike has been plaguing me with problems and as I sort them out another one arises. Carbs rebuilt, boots from airbox to carbs replaced everything tight and good, fuel system gone through, kreemed tank, new  plugs and wires, adjusted pilot jets per clymer manual, charging system checked and operating.

When I ride runs good until about 5000rpms or so then bogs out looses power. Went back through tuning section in clymer and decided to check the timing tonight. My previous experience had always been with a bike that had points which I always switched to a dyna/solid state with no moving points. This bike is a 79 and already stock with no moving points. First thing of concern was when I pulled the cover there was oil behind it. I dont know if this is normal but I assume this cant be right, my previous bikes never had oil behind them. I am at a loss as to where this may be coming from, how difficult it would be to fix and if it is a sign of a much larger problem. I am wondering if this is a seal of some sort, or if anyone has ever had any experience with something like this? I shot the timing and it was on and when checked the advance it was on as well, at this point though oil flew out, motor was bogging and oil also ran right onto the ground. It stopped when the engine was shut off.

[bellison80]

Oh yea here is a photo.

[Piute]

                                                               
                                                                  DAMN



http://www.bikebandit.com/houseofmotorcycles/1979-honda-cb750k/o/m2001#sch17832

[bellison80]

Any suggestions Plute?

[Piute]

                      Not enough EXperance in these models To say anything yet

                                                             
                                                    checking s.o.h.c.4 forum

                                                                 OOPS
                                              Forgot 79 dohc"search this forum
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                                            just got turned onto looking for parts

[bellison80]

I have a feeling there must be a crankshaft seal of some sort...it has gotta be coming from behind all the timing components. None the less having them soaked in oil cant be helping the way it is running haha. This thing is really testing my patience.

[TOOLS1]

I am not a DOHC guy, but I think there is supposed to be oil there. I know on some of the small Honda's when, you remove the timing cover there will be oil. Also on the bogging. It sounds like it is starving, for fuel. Check the vent in the gas cap. Also check fuel flow out the fuel line. If those are good, you might need to clean the carbs again.
TOOLS

[bellison80]

Is it possible Tools that when I kreemed the tank I could have obstructed the gas cap vent? I am hoping you are correct in that there is supposed to be oil behind there, This is my first DOHC, so I am not positive myself yet. The fuel line is flowing freely. I have cleaned these carbs so many times. I am determined though to get this thing running proper.

[TOOLS1]

It could have. I have heard of guys even kreeming there petcocks closed.
TOOLS

[bellison80]

I pulled the petcock haha, follwed their directions to a T. They did however say that when you are in the liner process to have the cap on while rotating the final liner and it did get on the cap. I am gonna take the gasket off and soak the cap in acetone.

[bellison80]

Oil behind the ignition cover

When you open the ignition cover, and find oil in there.... It means your bike probably has oil in it; because yep, there is supposed to be oil in there.  


Just found this on a DOHC FAQ's page so I think I am ok...back to the carbs I suppose........

[shinyribs]

Hmm,You wouldn't think so,would you?The wire in your picture has that certain type of oil-proof insulation that you only find where hot oil is present also.So thats another good sign!

I'm with Tools on the bogging.My bike did the same thing when I put pods on it.It was running lean,once rejetted it did fine.I'm not saying you need bigger jets of course,just that it does sound like a lean condition.Sounds like you are on the right path!Good luck

[bellison80]

I did have some difficulty while doing the tuning. The specs say 1-3/4 turns out for the initial setting. Then warm the bike up and turn each pilot out by another 1/2 turn if rpms increase by 50 go an additional half turn until it comes back. Then adjust idle speed. Next You go in until until there is a change of 50rpms again and then out an additional 3/4 turn...repeat on all four. So I tried using the tach to do this and it seemed impossible to read a 50rpm change either way. I rode it at each step to see how it was doing and it was bogging more the further they went out. I got to the second to last step and because of my difficulty reading the rpms...I stopped hear.

So as the jets go out this allows more gas to go into carbs? Just think that its still not getting enough gas...and what can I watch out for if it starts running rich?

[bellison80]

Oh and at the initial setting it seemed to run better than when i would get further out with the adjustment. But I did not go the final 3/4 at the end because I was having so much trouble trying to read 50rpm changes.

[shinyribs]

Sometimes it can be hard to tell the difference between a rich bog and a lean surge. A rich bog usually acts like trying to accelerate in too high of a gear and a lean surge will feel like running out of gas or it just falls on its face. Next time it does the bog tpu described, pull the choke closed. If it gets worse than you are already rich. If it improves than you are leaning put. The choke richens always. From what you are saying now, with the adjusents tpu made, sounds like its loading up. Doesn't make sense with not revving though. Try the choke think and go from there. Good Lu k.

[Re-run]

Pull your p;ugs out and see what they look like. That will be your indicator. Black is too rich, white of very, very light is too lean. You can turn those screws all you want but until you know if things are rich or lean, you won't get it right.
And yes, there should be a small amount of oil in that cover. Maybe a teaspoon or 2 though once the engine if off. it shouldn't fill with oil.

[LukeM]

I concur with this posting: my 1979 CB750L did have oil behind the left side engine cover.  It's to keep the starter gears lubed/oiled.  The ignition pickups do not mind the oil.  Just remember to put your bike on its center stand before removing that cover.  You lose a lot less that way.

Luke M

[bellison80]

Thanks Re-Run, Luke and Shiny. I Talked with a mechanic this morning also so I have some more to go on. Hopefully I can get it straightened out. She runs fine till about 5-6000 rpm then when you try to get on it spits and sputters. I did put premium gas in and wonder if that matters?

[rrgunslinger]

I'm doing my tank and the site suggested putting a plastic shopping bag over the hole then close the cap on top of it.  That keeps the liner material out of the cap.

 

On Mon, Mar 26, 2012 at 12:18 AM, bellison80 [via Honda CB750'S] <[hidden email]> wrote:

I pulled the petcock haha, follwed their directions to a T. They did however say that when you are in the liner process to have the cap on while rotating the final liner and it did get on the cap. I am gonna take the gasket off and soak the cap in acetone.

Brian E
Ann Arbor Mi
Current Bike: 1979 cb750f supersport
Previous: 1978 Kz650
              1993 Yamaha Fzr600
              1978 Suzuki gs550
              1984 Honda Elite 125

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NAML

[Re-run]

Premium shouldnt matter that much. The bike does not need it and most likely will not run any better with premium. But it shouldn't cause the issues you have.