My What Am I Getting Myself Into Combat Build Thread

Schwany said:
So the bike is ready, but you aren't? :)
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Pretty much LOL. We've had a cold front last couple of weeks. Should be over 50 tomorrow.

And don't plan on kicking it until i get oil return. From what i understand, that could take a while. I used copious amounts of assembly lube and total seal. I also pre-oiled the filter and sludge trap and plan to fill the oil returns. Think i should be good until i get oil return
 
TomU said:
And don't plan on kicking it until i get oil return. From what i understand, that could take a while. I used copious amounts of assembly lube and total seal. I also pre-oiled the filter and sludge trap and plan to fill the oil returns. Think i should be good until i get oil return
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Look Here!
 
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Well went to start it yesterday. There was good news and some bad news.

Good news, it started! Had to give it some throttle but it started.

Bad news. My convoluted fuel system is air locked

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The gas hose is higher than the petcock so it won't flow to the carb. There's only like an inch between the petcock and the carb inlet so not much room to work with. The setup i had hoped would work was a 'T' off both petcocks that fed a 1 in 2 out filter that then fed the carbs better seen here.

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Well i just could get the carb hoses below the petcocks without them kinking. I then tried it without the filter in an 'H' pattern with the petcocks feeding a 'T' then to a single hose going to another 'T' that then feeds the carbs. Couldn't get that below the petcocks either. Ended up directly feeding each carb from each petcock. That works, but i have no secondary filter and each carb is dependant on each petcock, i.e. if i loose fuel from one petcock, i loose one carb. If anyone has solved plumbing dual Mikuni's, i'm open to recommendations.

That was the easy problem, this is the harder problem

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Oh, and i have no oil return

Other than that, Happy Thanksgiving

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That’s a bummer. Fixing that breather will be a PITA.

But fuel line air lock theory is wrong IMO. Provided the height of fuel in the tank is above that looped hose, fuel will flow. The location of the petcock is irrelevant. You WILL probably see air in that loop when the engine is not running as, with it being the high point, air will always end there. But that’s not the definition of an air lock.

If in doubt, fill the tank, remove the float bowl plugs and turn on the petcock. I guarantee you’ll see fuel.
 
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Did you grind down a cheap wrench and try to tighten that breather a little more? Maybe you'll get lucky, and it just needs a bit more torque. If not, you are in for a fluster cluck of a job.

No return oil is not good. Did you try the method I suggested to get return oil flowing before starting it? Are you sure you have oil pressure? Only thing the puddle under the reed valve leak proves is you have crank case pressure and oil in the sump from a little wet sumping.

Thoughts about the fuel line:

(Caveat is I do not have a Commando, and I have some room for fuel line plumbing as well as air filters on my version Norton. That and I don't care that much about what it looks like.) Move the rocker oil feed line outside the carburetion so you have room for the fuel line between the carburetors. Use two T's up high in an H configuration. You would not be able to use the big secondary filter though. The filters on the petcocks do an OK job at keeping fuel blocking junk out of the carburetors. An alternative (if there is room) would be to leave the rocker feed line where it is and swap the petcocks so they point toward the rear and the handles are to the outside and build your H fuel line plumbing from there. Maybe figure out how to use the dual output filter with one T. You might be able to get really small plastic fuel filters on if the dual filter is too large to use anywhere. Third alternative is leaving the fuel line plumbing like it is and fix everything else first. Once you get out on the road you'll find out if it is starving for fuel.
 
Schwany said:
Did you grind down a cheap wrench and try to tighten that breather a little more? Maybe you'll get lucky, and it just needs a bit more torque. If not, you are in for a fluster cluck of a job.

No return oil is not good. Did you try the method I suggested to get return oil flowing before starting it? Are you sure you have oil pressure? Only thing the puddle under the reed valve leak proves is you have crank case pressure and oil in the sump from a little wet sumping.
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Tom and I have talked about all this.

He has tightened - that's not the problem. The kit for 1972 is very nice - however, the gaskets that come with it are not made correctly. I wish cNw would warn people. The holes are too small and not perfectly aligned. If you don't correct that before installing, the gasket rips and if you don't notice it, you'll have a leak. Tom will pickup gaskets from me, I have extras - when I buy new kits, I ask cNw for extras as even being careful you can tear them while opening the holes.

I would have thought that Tom is not waiting long enough since he pre-filled the system, but the breather is continuing to return oil after any wet sump should be cleared. He has excellent oil pressure. He's working on verifying that there are no blockages in the return but it's all new so that's unlikely.

Since there should be nothing but air in the breather, that oil is leaking goes along with the breather returning oil.
 
Yeah i re-tightened the breather but it actually made it worse. The problem is the gasket. It's a little off at the holes. If i recall correctly, it's slightly too small so it bunches the gasket when you put the bolts through the holes. The holes need to be expanded which is not easy because they are small and the gasket is thin and there's not much room to the outside on the gasket for expanding. I optimistically thought it would flatten out when compressed and wouldn't be an issue. I also used some loctite sealant (forget which one of the top of my head, but it's red and thin). That did not work. I am hoping i can get get it off from the bottom, but there's like one bolt that might have a clearance issue with the gearbox.

Not sure why the oil is not returning. I have a temp oil pressure guage at the left rocker inlet. I'm getting pressure there. Maybe it's that i just can't see the return because the breather is constantly gushing over the return tube. Maybe that's a clue, i don't think the breather should be constantly doing that. I pulled the return hose and checked the tube that goes to the tank and that is clear. Next i plan to either kick it or start it to see if i get return at the hose that connects to that tube.

The gas line is the least of my problems at the moment. I have a temp gas tank on and will address the fuel line when i go to replace that

EDIT: I was typing as Greg replied :)
 
Fast Eddie said:
Tom, on the bright side, at least you found all this now and not next spring !
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Yes, and 60+ (15c) degree days are a shame to waste in late November! Hopefully he can get it all resolved by tomorrow or Monday - supposed to be warm and sunny both days.

The oil leak can be fixed over the winter - it's not that bad and once oil is returning properly there shouldn't be any oil there to leak except after a wet sump.
 
Excuse this underthinking diversion.

I shredded one of the cNw gaskets when removing the cNw breather during an engine teardown. Due to being a shade tree barnyard mechanic I made a new gasket out of card stock. Doesn't leak, tear, or squeeze out. For the bolt holes in the gasket, I used a hole punch or one of those paper punches used for putting holes in paper for a 3 ring binder. Whatever was the right diameter. I do that kind of thing frequently. Who wants to wait 4 days to get a small simple gasket, when you can just make one? OK everybody but me. lol
 
Yeah the CNW gaskets are crap IMO. Jim Schmidt should make gaskets for their breather. I'd gladly pay a couple extra bucks for a better gasket.
 
TomU said:
Yeah the CNW gaskets are crap IMO. Jim Schmidt should make gaskets for their breather. I'd gladly pay a couple extra bucks for a better gasket.
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Ha, Jim would be helping the competition in that case.

Jim sells a sump plug position reed breather and a cam, timing case, or rear of crank case reed breather. If I had a different exhaust, one that did not go right under the sump plug, I'd use his low profile sump breather.
 
Good point. Still, Matt need to include a better gasket. Was going to just enlarge the holes on his gasket, but you got me thinking on making my own.

Bad news aside, i took the risk of riding it to see if the gearbox was working correctly. Thankfully no problems there :) (at least through the first three gears). I was a little anxious at first having not ridden a bike in nearly 30 years but soon everything came back. It was glorious. I probably rode it a little longer than i should (a quarter mile at most), but it was awesome.

Now back to the fiddling
 
Congratulations. Its a joyful event for this group when a rebuild comes to life. A win for all those that contributed and a happy result for those that just followed along (like me).
 
Hope you got it sorted on this rainy cold day! Tomorrow and Tuesday are supposed to be decent days for testing. I hope so, I got the 69S back together and need to test it.

BTW, we are both lucky it wasn't a rattlesnake!

What does that mean: I looked all over the shop yesterday for my Locktite 620. Tom stopped by and looked all over too. Both of us had our hands within 1/2" of it and didn't find it. I accidentally found it today. The only thing that would have been more annoying is if it had been where it belonged and we couldn't find it.
 
It's like when you drop something small and it just disappears to never be seen again and you decide to drop something the same size to see where it bounces to find it has disappeared lol next thing you know you're looking for both, that's when you walk away and come back later you usually find both doing that, I got a habit of putting things down and a few minutes later can't find it.
Was working on my old Triumph once put tools down beside the bike I was working on came back to find the allen key and a pair of pilers completely missing, had to go borrow a allen key to finish the job off then one day (I shared a house with a mate and his dog) I seen his dog grab a spanner that I been using so followed him to his bed to find my missing allen key and pilers as well a few other tools, well put it this way he never did that again from a bit of training from me.

Ashley
 
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