300 probs????? help??

[wence]

Hi all,
Just spent about two hours going through some searchs for powervalve and lack of top end issues(rich bogging up top).
I have to check the huses to the pv and ensure no blockages but....
Since the bogging up top problem has occurred I have noticed a lot of oil coming out the left side powervalve drain tube.There used to be a little here and there but now quite a lot is coming out.
Is this related to the lack of top end?
I have the engine apart as I speak and would like to fix anything now instead of later.
While asking questions:
How do you separate the right side powervalve bearing from the valve itself, it seems to have a washer or something holding it on but I cannot remove it to remove the bearing????

Thanks in advance,
Mark

 

[Caravan Monster]

When you say bogging on top end, does it rev cleanly thru' the midrange, bog in the lower top end, then rev cleanly thru' the rest of the top end ? Erratic tickover ?

If so, it might be worth double checking the rings and the clutch side main bearing seal. I've just started on my EC300 engine because of similar symptoms. Found gearbox oil all over the crank

 

[wence]

I may have to change the bearing seals.
My main seal has been centre tapped to hold it in (security?), is this normal?
I guess I have to rip out old one and file the divots out gently?
The bike bogs here and there thru the rev range when warming up but when hot it only bogs at WOT when snapped open.If you hold it not quite Wot it is not so bad.Thinking about it could the oil coming out the pv breather be trans oil?
Thanks for your help.
Mark

 

[wence]

Just thinking about it and something Glenn said together with caravans reply.
This started again after the main crank bearing (ignition side), disintergrated.
I could not replace seal due to hole punch divots and it looked fine.
I would be putting money on the crank seal thinking about it.
I will change it today.
Ignition side would not be leaking into the crank though and there is no oil in ignition.
Mark

 

[GMP]

Mark,

The left PV drum valve opens the chamber with the drain to the exhaust at low RPM and closes it at high RPM the same time the the main flap rises at high RPM. It the PV is not moving to its high RPM position quickly or completely enough, it would be reasonable to think that the chamber would foul with oil and drain more, just like if you ride a lot of slow technical trails rather than faster stuff. I still say that if the trans side main seal was leaking it would smoke like you have never seen before, as gear oil is not designed to burn clean. I suppose you could have a lean bog from a leaky ignition side seal but I would think it would hang idle and have other symptoms. Its easy enough to test with starting fluid and/or pull the stator for a visual.

The PV bearings are simply a light press fit on the drum valve shafts. Disconnect the actuator rod and move the plate through the range, looking into the exhaist port. You should see the drums rotate so the slots no longer form a path to the chamber. In the full open position the flap is high and the drums open the aux exhaust ports. It should be smooth and easy to move, actually very easy and on the loose side. Its very simple once you observe it.

 

[wence]

Thanks Glenn,
I have the motor apart and the ignition seal shows no sign of leaking at all , no oil in ignition side.
Also no smoke like you are describing , just the normal.
I have completely dismantled the powervalve now, thanks for the help, and am in the process of cleaning . I will buy three new bearings.
The pushed on spacer outside the right side bearing was a gummed up very tight fit and needed to be persuaded.
Hopefully , by cleaning up the powervalve I should have a correct idling bike.
While apart I was thinking I may take out a washer between the spring and powervalve governor to reduce spring tension.What do you think?
I am also in two minds as to changing the crank seal?
Anything else I can do that is cheap and may have a postive effect while she is in pieces?
Thanks again ,
Mark

 

[gasgasman]

Power valve service..........

http://www.gasgasons.com/index.php?site=static&staticID=133

 

[wence]

Thanks gasgasman ,
That is very informative.
I have to clean mine now and then refit.

Cheers Mark

 

[wence]

Ok,
A happy ending......finally.
I had the motor apart again after the clutch cover gasket drained the oil from my bike and she got hot.
This time while checking the gearbox etc for heat related issues I rechecked the carby, refitted the hoses blew out every orifice with air and reset float level.I also put new bearings in the PV and cleaned the whole setup.
I found the PV flapper was rubbing on the back of the cylinder and ground the flapper a touch at the points that were touching.
Checked fuel tank and removed petcock.
I found sand in the fuel tap itself and a little around the filter in the fuel tank.
Rinsed tank with metho and thoroughl=y cleaned filter and fuel tap.
I changed the reed valves( petals) , and turned them upside down( they were quite rough around the edges.
Tidied up reed block and made sure all was sealing correctly.
I cleaned stator contacts with an electrical polishing block and greased the gasket etc.
Sprayed cotact cleaner in cdi last race and that did not help or hinder so cdi was fine I assume.
Anyway one or a combination of the above has cured the bike and it is now back to its former power and glory.
I have a feeling it was the fuel tap blockage, (part blockage), and maybe stator pickups?
Thought I would keep you guys in the loop anyway.
Thanks to all who helped,
Mark

 

[GMP]

Mark,

PV flap should have plenty of clearance and not bind, sure it was installed correctly(not upside down) the first time? Anyway, glad its fixed.

 

[wence]

Glenn,
It was in correctly but it has been rubbing on the back of the cylinder as you could see a mark on each side.
All good now though.
Thanks again ,
Mark

 

[GMP]

Very odd, perhaps some casting flash that was not cleaned up.

 

[wence]

I reckon you would be spot on there mate.
It looked a little rough in behind there.
Cheers Mark