1971 Build for Dad

I’m not familiar with your bike, but I am familiar with drum brakes. The shoes should be touching the drums when they are released. They should begin to engage as soon as you begin to apply pressure. Once you grab a handful, they’re pretty much self energizing. It shouldn’t take the Incredible Hulk to get it stopped.
 
Bike looks great! Pics may help get a better idea on where the oil is coming from.

As to the front brakes, I race honda's with twin leading shoe brakes and we can get them dialed in to be almost as good as disc brakes--truly. The key to getting them perfect is a a few variables that add up to really good brake feel.

1) Shoe prep: The single most effective thing you can do is to turn the shoes to match the profile of the drum. Setting them up in a lathe on their hub ensures the profile is spot on, and will give the most possible contact patch against the drum. This is a massive benefit and when you feel a drum brake that has had it's shoes turned vs. one that hasn't...it's literally a night/day difference....however, most of us don't have a lathe set-up where we can do this nor know where find someone that can do it. Sometimes, just sanding the front edges of the shoes will help the shoes bed in better... note: shoe profiles vary based on brands--some better than others. You'll still be able to dial in your brakes with steps # 2 & #3, but just know that this step will take your braking from 65-85% to 100%.

2) Setting the brakes. Not sure what the XS manual says on this, but we've found that the best way to set up these brakes is to have the rear shoe act just a fraction sooner against the hub than the front shoe. Something about slop with linkage/leverage acting differently on the two arms... anyways, here's what we do to set the brakes up: Lift the front so that the wheel spins freely. Back off everything, at the lever, at the rear shoe linkage and at the front shoe...so that the wheel spins free and you KNOW there is nothing that is in play at the brake. Next, spin the wheel and start to adjust the front shoe only (the rear shoe is connected obviously, but you should have backed it off so that it's not actually rubbing the hub. If the rear shoe starts to rub at any point while you are adjusting the front, you need to back it off more and/or the arms are in the wrong location on the splines). You're listening for when the front shoe just begins to drag against the hub. At the point you hear it drag, stop. Now...back the front shoe up by a 1/8-1/4 of a turn, just enough that when you spin the wheel you don't hear anything... and start on the rear shoe's linkage adjuster. You want want to adjust this shoe independently of the front so that it just starts to drag against the hub. Again, you're listening for the sound. Once you hear the shoe just kiss the hub, stop. Lock it in and lock in the front adjustment. You're done with the shoes, and have set them so that the rear shoe will make contact just a smidge before the front shoe. now set the lever to your desired comfort, but note: unlike a hydraulic brake where you can set the brake lever relatively tight...with a drum brake, you want to have it a little loose to help with leverage. I usually set mine so that there's a 1/4" free play at the lever- more or less. Too tight and it will feel like you're squeezing a brick. Too loose, and the lever will be at the grips before you lock up the front wheel.

3) Cable length/routing: Ideally, the cable length is just long enough to allow the bike to turn freely, but not so long that there's a lot of excess (long arching loop if that makes sense)...the reason being is the longer the cable the more "flex" it has when you pull the lever...thus, the torque at the lever gets absorbed in the cable and not the brake actuator arm. Many of the aftermarket cables available for our bikes (Honda's) are just too long. They'll work ok for the street, but often we cut them down and make our own lengths and route them with very minimal bends. Can't tell by your pic, but the cable you have doesn't look excessive.

Anyways, hope this helps.
 
Hello All! My apologies for dropping off the radar... Work was absolutely crazy for the past month with the rise of the Delta variant in Missouri. Also, after getting the '71 started, I realized I was tired and needed a break. I am a firm believer that garage projects should never turn into work... totally defeats the purpose. My shop hovering around 90-95 degrees was also a factor.

That being said, I have recently gotten back into this bike. I went through it very carefully and I am so glad that I did. Made some "useful" discoveries, such as the motor mounts and the front axle clamp not being torqued down!

Eventually, I did get it on the road:

View attachment 197348

View attachment 197349

Not my best bike pictures, but I don't really trust it enough right now to go too far from the house. Why you ask?

The oil hemorrhage is one reason :thumbsdown:. After a 10 mile ride I noticed that a fair amount of oil was getting blown out of the engine. It was hard to tell from where, but I think the cam chain tensioner assembly and/or upper cam shaft seals are likely culprits. Any other places you think I should check?

The front brake was the other big issue. And by that I mean it hardly works at all :eek:! I set the linkages as described in the Clymer manual, but I am clearly missing something here. I will probably just take it all apart and go from there. Any tips?

The good news, the engine runs pretty damn good and it sounds great! The only issue is that it will occasionally fall on its face at higher revs. Hopefully a little tinkering with the carbs will take care of it. It is amazing how differently it handles as compared to the '80, much more nimble and responsive. Is there a big difference in weight between the two models or it is just tires/chassis/suspension?
The good news, the engine runs pretty damn good and it sounds great! The only issue is that it will occasionally fall on its face at higher revs.
Which is exactly what my XS2 did in 73. Very annoying and nigh on impossible to cure.
 
I appreciate all of the feedback on this last set of issues. As this bike was kindly nominated for the calendar, I felt it necessary to get it running as good as it looks!

The front brake took a bit of guess and check, but I finally have it stopping the bike in a reasonable distance. It still isn't as good as the disc brake on the '80, but at least it is ridable now. Small victories...

The carb issues were largely resolved by careful adjustment of the fuel screw using the "dead cylinder" technique and synchronizing. All that I am left with now is a minor and intermittent backfire. It looks like it is running a little rich, but the current plan is to evaluate the plugs during the 100 mile maintenance mark. By and large, it is running much better, I'll take it!

And the oil leak... The good news is that the "hemorrhage" was caused by an old seal on the dipstick. I replaced it with a new cork seal and it is losing much less now. However, I suspect that a few other areas are leaking on me. I know for sure that the union bolt on the bottom of the oil delivery pipe is weeping some oil. Not sure what to do here, as it is already torqued to spec. Maybe Dad forgot to anneal the copper washer during the install?

The other leak is more elusive. After a 15 mile ride I am getting some "blowing" oil on the cylinder fins, carbs, and side cover.

upload_2021-9-27_15-27-15.jpeg


upload_2021-9-27_15-27-24.jpeg


Any ideas? The camshaft seals are at the top of my list, but visually inspecting them, they look fine. As the oil seems to have some force behind it the source has been hard to nail down.
 
I appreciate all of the feedback on this last set of issues. As this bike was kindly nominated for the calendar, I felt it necessary to get it running as good as it looks!

The front brake took a bit of guess and check, but I finally have it stopping the bike in a reasonable distance. It still isn't as good as the disc brake on the '80, but at least it is ridable now. Small victories...

The carb issues were largely resolved by careful adjustment of the fuel screw using the "dead cylinder" technique and synchronizing. All that I am left with now is a minor and intermittent backfire. It looks like it is running a little rich, but the current plan is to evaluate the plugs during the 100 mile maintenance mark. By and large, it is running much better, I'll take it!

And the oil leak... The good news is that the "hemorrhage" was caused by an old seal on the dipstick. I replaced it with a new cork seal and it is losing much less now. However, I suspect that a few other areas are leaking on me. I know for sure that the union bolt on the bottom of the oil delivery pipe is weeping some oil. Not sure what to do here, as it is already torqued to spec. Maybe Dad forgot to anneal the copper washer during the install?

The other leak is more elusive. After a 15 mile ride I am getting some "blowing" oil on the cylinder fins, carbs, and side cover.

View attachment 198881

View attachment 198882

Any ideas? The camshaft seals are at the top of my list, but visually inspecting them, they look fine. As the oil seems to have some force behind it the source has been hard to nail down.

I had that exact same weeping, doing exactly what yours looks like and it was indeed the cam seal. It was not a large leak, it just kind of weeps until it build up a small puddle inside the housing then it leaks out from under the chrome cover and blows back. Pull your chrome cover off and you should see it.
 
I had that exact same weeping, doing exactly what yours looks like and it was indeed the cam seal. It was not a large leak, it just kind of weeps until it build up a small puddle inside the housing then it leaks out from under the chrome cover and blows back. Pull your chrome cover off and you should see it.
The same issue for me. My leak is under the cam cover.
 
The other leak is more elusive. After a 15 mile ride I am getting some "blowing" oil on the cylinder fins, carbs, and side cover.

Assuming new gasket and seals o rings it looks rather much for a 15 mile ride Inside is 3 bolts
no 37 I would start to check that those are not loose before the rest


upload_2021-9-27_23-7-36.png






 
Make sure they've been installed deep enough in the housing. The end of the cam doesn't stick out very much so the seal needs to be pressed in all the way to the point of it's back side being flush with the back side of the cover. Also, there are some thicker aftermarket seals out there (7MM thick) and they don't work as well. Since their seal lip is on the front or top of the seal, pressing it in all the way still has the seal lip farther out than an original seal's would be. I recommend getting original replacements directly from Yamaha, they're only 5mm thick.
 
Hello All! My apologies for dropping off the radar... Work was absolutely crazy for the past month with the rise of the Delta variant in Missouri. Also, after getting the '71 started, I realized I was tired and needed a break. I am a firm believer that garage projects should never turn into work... totally defeats the purpose. My shop hovering around 90-95 degrees was also a factor.

That being said, I have recently gotten back into this bike. I went through it very carefully and I am so glad that I did. Made some "useful" discoveries, such as the motor mounts and the front axle clamp not being torqued down!

Eventually, I did get it on the road:

View attachment 197348

View attachment 197349

Not my best bike pictures, but I don't really trust it enough right now to go too far from the house. Why you ask?

The oil hemorrhage is one reason :thumbsdown:. After a 10 mile ride I noticed that a fair amount of oil was getting blown out of the engine. It was hard to tell from where, but I think the cam chain tensioner assembly and/or upper cam shaft seals are likely culprits. Any other places you think I should check?

The front brake was the other big issue. And by that I mean it hardly works at all :eek:! I set the linkages as described in the Clymer manual, but I am clearly missing something here. I will probably just take it all apart and go from there. Any tips?

The good news, the engine runs pretty damn good and it sounds great! The only issue is that it will occasionally fall on its face at higher revs. Hopefully a little tinkering with the carbs will take care of it. It is amazing how differently it handles as compared to the '80, much more nimble and responsive. Is there a big difference in weight between the two models or it is just tires/chassis/suspension?

Bike look absolutely great; really nice job.
 
Great video! Damn those cam seals! It was also nice to hear the valve chatter for comparison. I've not ridden many bikes, but it seems like the 650 engine has an especially noisy valvetrain.
My bike was running on the center stand perched upon the HF lift. That makes a bunch of noise. But yes, there is some clatter with the valves set properly.
 
Great video! Damn those cam seals! It was also nice to hear the valve chatter for comparison. I've not ridden many bikes, but it seems like the 650 engine has an especially noisy valvetrain.

Hi Rhy,
a quote from the 1930s:-
Complainant:- My Bugatti's engine sounds like a bucket of ball-bearings pouring onto an iron plate.
Ettoire Bugatti:- From the description, your Bugatti's engine is running perfectly.
 
Make sure they've been installed deep enough in the housing. The end of the cam doesn't stick out very much so the seal needs to be pressed in all the way to the point of it's back side being flush with the back side of the cover.
This was it! They needed to be seated in just a few millimeters, but that appears to have done the trick. I did about 40 miles on it yesterday and not a DROP of oil! I'm a happy camper!

It is starting to feel like a solid machine. Next item on the list is clutch adjustment. During my ride it became progressively more difficult to shift gears. Finding neutral was virtually impossible and I noticed it was pulling ever so slightly with the clutch lever in.
 
Yes, proper clutch adjustment can take some fiddling. Do as much of the adjusting and elimination of freeplay using the adjusting screw down on the worm, then finish with a little final adjusting or "fine tuning" up at the perch and lever. The big issue with this clutch is that as the engine heats up, the alloy engine cases expand more then the steel clutch pushrods. This results in more freeplay at the lever. More freeplay means less pushrod thrust and less clutch plate separation, and the clutch can start dragging. Neutral becomes hard to find, shifting can get more difficult, and like in your case, the bike can try to pull ahead when stopped in gear with the clutch pulled in. To help ward this off, most of us set our worm screw adjustment a little tighter than the factory spec. The spec says to back the adjuster screw off about 1/4 turn after it makes contact with the pushrod. We only back it off about 1/8 turn.

What I also like to do is "fan" the clutch lever while I'm adjusting the worm screw. By that I mean pumping the clutch lever in and out just through it's freeplay range, until it just hits the point where the freeplay is gone and it would start disengaging the clutch. There are a series of balls and rods between the worm gear and the clutch, many inside the engine and bathed in oil. "Fanning" the clutch lever will push and stack them all tightly together, squeezing out any oil between them and taking up any slop or freeplay. If you turn the worm gear adjusting screw in until it stops, then start "fanning" the clutch lever as you continue to exert inward turning force on the screw, you'll often find you'll get as much as another 1/4 turn in on the screw. Only after doing that do I back it out a little (1/8 turn) and lock it down.
 
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