Advice on a 1979 Convert

[Fraser]

Hi lads,

Here is my first post. Purchased a 1979 V1000 Convert, sight unseen via our local version of eBay, it was supposed to have been a “good runner”, it was also in the first stages of being converted into a cafe racer so many body items were removed in anticipation of replacement. The original items all came with the bike. However, it appears that the bike had sat for a few years, so lubricated the cylinders before starting, removed and cleaned the carbs, petrol tank, replaced fuel taps, petrol filters, fuel lines, spark plugs, air cleaner etc. Now at the stage where everything is back together and the bike running, it always starts first time.

But here is the issue; the crankcase is being pressurised and oil is being discharged from the base of the rubber plenum attached to the air cleaner. Also, the L/H cylinder was very smokey some times when it started, so thought that the piston rings might be at fault. Have done a compression test (motor cold and throttle fully open) to try and verify the thinking and we get 160 psi for l/h and 180 psi for r/h. Put a little oil in the l/h cylinder and the pressure jumps up to 200 psi, so am thinking that the rings are at fault.

My question is; as the bike sat for a few years is it possible that the rings are just “gummed up” and some regular use would get things resealed, or is this just wishful thinking on my part and I need to face reality and replace the piston rings? The bike has done just over 58000 miles.

Thanks for your help, cheers.
Fraser. 

[dblue]

check the crankcase ventilation valve, may be rusted shut.
Dave

[rodekyll]

Hello, and welcome.

The problem is that your bike is in NZ, and is therefore upside down.  We expect oil leaks when the bike is in that position.  The correct fix is to send it to me where I can right it and ride it.  No, I don't charge for the service.

[rodekyll]

Seriously though, the smoke isn't an issue yet.  You've got several weeks of condensation and goo built up in the mufflers.  It will take a few rides to blow it all out.

The compression is possibly an issue.  I don't think it would hurt to crank the pistons down in their bores and soak them in marvel mystery oil or whatever the upside-down version of that stuff is.  Then ride it a little (maybe until the smoking stops) and see what you've got.  If the compression continues to be wonky, then a leak-down test is in order.

[oldbike54]

'One question RK , as one of our 'Vert 'Sperts , why don't things simply fall off the planet in NZ and 'Stralia ? I mean , what's holding them on  ???

Seriously , Blue is on to something , and it could just be stuck rings .
 
  Dusty

[rodekyll]

I'm glad you asked that, Dusty.


Two models -- USA* and "world" back then.  The world model had the flux capacitor and was therefore suitable for the environment.  The USA model did not.  However, due to the expense of the FC, very few world models were sold.  Most of the 'verts you now see down under are the results of unscrupulous dealers importing gray-market USA models and simply turning the badges upside down.  The unauthorized mod may have delayed the oil problem, but only for a few decades.  As has been subsequently demonstrated on U-tub.e, the proper fix (The OEM FC is unobtanium since the embargo) is to flop the compression rings and install a left-threaded hose clamp on the scraper ring.

OR SAVE THE GRIEF AND SEND THE BIKE TO ME.  Again, I do not charge for the service.

*There is also the "euro" version that has been designed to run on the wrong side of the road, but they made it only in pink so we don't usually include it in our lies.

[Cam3512]

I wanna know if the toilets flush counter clockwise.  Really.

[oldbike54]

 :D :D :D :D :D :D :D
 So that explains the Lithuanian neighbor with the pink 'Vert I had in Texas . I just thought it was a faded red  ;D

 So sorry for the drift Fraser , we aren't normal around here in the Winter . <shrug > We will try to be serious  ::)

  Dusty

[oldbike54]

I wanna know if the toilets flush counter clockwise.  Really.

Yup , it's because the engineers down under study up side down  . OK I'll stop now  :-[

  Dusty

[Kiwi_Roy]

check the crankcase ventilation valve, may be rusted shut.
Dave

Do these bikes have the little vent tank with the spring loaded valve like a Eldorado?

At 58k the bike should have lots of life left perhaps run some additives in it for while.

[Antietam Classic Cycle]

Do these bikes have the little vent tank with the spring loaded valve like a Eldorado?

At 58k the bike should have lots of life left perhaps run some additives in it for while.

Not from the factory. They have a horribly designed (IMO) combination airbox/breather system.



It uses this type of check valve:



It's not unusual for the ball to become rusted stuck.

[Fraser]

Lads,

Thanks for the comments.
It is a USA bike but I'm not holding that against it (going through our local compliance and registration process now, it might never end!).

Antietam thanks for the parts diag, is the check valve item #50?

For cam3512, can't answer the water flushing direction as this implies a water reticulation and sewerage system, we can only afford a hole in the ground. However, it is a very deep hole and may one day emerge in New Jersey.

Will try a soak with the marvel mystery oil and see how what happens.
Cheers,

Fraser.

[Antietam Classic Cycle]

Antietam thanks for the parts diag, is the check valve item #50?

Yes, the check valve is #50.

Charlie

[injundave]

Fraser, whatever you do don't get them started on sheep.......... The check valve on my T3 became clogged and spat oil out everywhere. I put one of the later ones on and it cured it immediately. Of course I had to install it downside-up so that it would work.

dave

[mgfan]

Re the toilet, Yes it does!  :BEER:

[twhitaker]

I believe that model has iron cylinders and since the bike sat for years rust could be the culprit.

[mtiberio]

I always remove the check valves. might as well let the motor suck oil back down as well as push it up, rather than forcing it to go all the way around and back to the drain...

Those old breather boxes were barely adequate, and especially without a sump spacer... Make sure you do not run more than 2.5 liters of oil in the sump after a change. No more than half way up the stick. Any more and you will pump out tons, it goes in the airbox, and will get burned or leak.

I remember my first convert, making a hard run on the highway, and having to chop the throttle. You would have thought my bike was a bug fogger from the tons of smoke out the back.

if you are really concerned about stuck rings or varnish, I'd run a few tanks of "sea foam". You can also add it to the oil as well, but I never have and don't like the idea of thinning the oil. do you have "Sea Foam" down under?

[LaMojo]

'One question RK , as one of our 'Vert 'Sperts , why don't things simply fall off the planet in NZ and 'Stralia ? I mean , what's holding them on  ???

  Dusty

Well...its those sticky tires of course.  Lousy tire mileage though.

[oldbike54]

Well...its those sticky tires of course.  Lousy tire mileage though.

 :D :D :D :D :D

 Good morning Jack  **C

  Dusty

[Groover]

The check-valve assembly broke on mine and the ball ended up inside breather box (part 3 in the diagram).

Congrats on your bike purchase!

[John A]

The check valves with the round opening can completely close off when the ball seats in the round opening. This will cause oil, about a liter, to be rapidly pumped out the breather drain, until the oil level is below the end of the submerged drain in the crankcase. It's a surprise when it happens because it will happen at road speed and coat the rider behind you who hopefully not your favorite riding partner. The check valves were changed to have a square opening which could not close off.

[charlie b]

Or, the oil just coats your rear tire and makes for fun riding  :)

I also chopped off the oil return line in the oil pan area so it is always above the oil level.

[Pancake]

I also chopped off the oil return line in the oil pan area so it is always above the oil level.

Doesn't this mean that crankcase pressure is pushing up the return tube, possibly not allowing oil to return?

I was running without a check valve recently but found a lot of mayonnaise in the pipes. I put one back in and will see how that fares.

[mtiberio]

Doesn't this mean that crankcase pressure is pushing up the return tube, possibly not allowing oil to return?

+1

[bigbikerrick]

Hi Cam, Re:

For cam3512, can't answer the water flushing direction as this implies a water reticulation and sewerage system, we can only afford a hole in the ground. However, it is a very deep hole and may one day emerge in New Jersey.

hey Cam, I heard on the news that a  suspicious hole opened up a while back in Newark....Could that be  the deep hole our friend from down under is referring to? ;D
Rick.

[rodekyll]

No, the Newark hole is routine -- the latest archeological dig for Jimmy Hoffa.

[oldbike54]

Ouch !  :D

  Dusty

[charlie b]

+1

Doesn't this mean that crankcase pressure is pushing up the return tube, possibly not allowing oil to return?

I was running without a check valve recently but found a lot of mayonnaise in the pipes. I put one back in and will see how that fares.

Have not had that happen.  The crankcase pressure is allowed to vent.  The hoses are big enough that they don't seem to restrict the flow back into the sump.  This is not unlike venting in the old days before emissions controls.