Yam_Tech314's official build thread

[G_YamTech_314]

So far I haven't done a whole lot to this bike, just taking it slow, as I have all winter to come up with a final product (or at least one I'm able to ride.) It just has a new battery, and a carb clean inide and out. The way I see it: spark first, fuel second. That being said. The next step it the gas tank. Its rust is leaving me scratching my head, and I'm pretty sure I wanna do the muriatic acid treatment method. That being said, I made some plates and gaskets to seal the pet cock holes. So far all seems well but I also want to pull as many dents out of it as I can. I'd also like to sand down the tank and paint it. My question is this: once I de-rust the tank, what's the best way to KEEP it rust free, while also not having it full to the top with fuel... hard to paint a full tank, and I dont wanna paint a tank before putting it under acid. The plates were creatively (primitively) made with extra snap on tool box dividers I found in my school tool kit. Pretty handy!

 

[grizld1]

You're taking the right approach to trouble shooting--ignition first. Re. the tank, that topic will stir up as many opinions as oil, but here's my 2 cents. A lot of guys swear by Kreem, Red Kote, and POR15, and a lot of competent guys have reported failures with same. I've used Caswell 2-part epoxy liner on 3 tanks over the last 5 years and they've all held up fine under regular doses of 10% ethanol gas. I'm a bit AR when it comes to prep. The tank gets soaked with a 50-50 mix of denatured alcohol and acetone to dissolve any varnish and associated crud, then it gets rinsed with water, then it gets filled with Metal Rescue rust remover and allowed to sit, then another water rinse, then a rinse with denatured alky take up any remaining moisture. Then it sits while the alcohol evaporates, and finally the epoxy goes in. If you follow Caswell's directions on mixing and ambient temperature and seal the filler hole carefully, it'll be fine.

Re. dents: even if you're really, really good you'll probably need to use some filler. Issue: your tank expands and contracts when temperature changes; Bondo, etc. will eventually crack out around the edges of the repair. Solution: USC All Metal and Evercoat Metal-2-Metal are aluminum bearing fillers that expand and contract with the tank. Both have worked very well for me over the years. They're more expensive than Bondo, but what's your paint job worth?

 

[G_YamTech_314]

You're taking the right approach to trouble shooting--ignition first. Re. the tank, that topic will stir up as many opinions as oil, but here's my 2 cents. A lot of guys swear by Kreem, Red Kote, and POR15, and a lot of competent guys have reported failures with same. I've used Caswell 2-part epoxy liner on 3 tanks over the last 5 years and they've all held up fine under regular doses of 10% ethanol gas. I'm a bit AR when it comes to prep. The tank gets soaked with a 50-50 mix of denatured alcohol and acetone to dissolve any varnish and associated crud, then it gets rinsed with water, then it gets filled with Metal Rescue rust remover and allowed to sit, then another water rinse, then a rinse with denatured alky take up any remaining moisture. Then it sits while the alcohol evaporates, and finally the epoxy goes in. If you follow Caswell's directions on mixing and ambient temperature and seal the filler hole carefully, it'll be fine.

Re. dents: even if you're really, really good you'll probably need to use some filler. Issue: your tank expands and contracts when temperature changes; Bondo, etc. will eventually crack out around the edges of the repair. Solution: USC All Metal and Evercoat Metal-2-Metal are aluminum bearing fillers that expand and contract with the tank. Both have worked very well for me over the years. They're more expensive than Bondo, but what's your paint job worth?

AWESOME advice for products. They seem great. Especially the pricey bondo+ lol. I have a professional autobody painter for an uncle, so I'm lucky to be getting lessons from him when the bike is ready for paint. My concern with sealers in the tank is that they crack over time. And when they do, how the hell do I get the chunks of old liner out??? I'll probably just be sure to put some good filters in the fuel system, and do my best.

 

[G_YamTech_314]

So, I finally got around to cleaning the tank insides. Turned out very well. However. I still had the tank flash rust so now I'm gonna need to figure that out... On top of trying to find a "special pin" for the gas cap... I need to find a way to keep rust away from bare metal without using a sealer. Unless someone can convince me otherwise...

I GOT IT TO RUN! So that's a major plus. Lots of tapping... Perhaps it's from the 28°F weather/some oil, or maybe it needs a valve adjustment... More to come later on... The good news is: it runs. Bad news? Needs a carb rebuild (no surprise there) and more than likely a valve adjustment. I'm happy it runs, but I don't wanna get excited and let it run and drive anything. Any tips on keeping rust outta the tank for winter?? Either way.. here's a video of it's first breath since I've owned it, and some before and after pics! Enjoy!!! (Any advice is MUCH appreciated. Thanks in advance...

 

[5twins]

Yes, do check the valves, and the cam chain tension too. Also inspect the tensioner screw/plunger assembly to make sure the copper damper washer is there. For some reason, they often go missing, and the motor can tick like the valves are loose if it isn't there.

 

[grizld1]

If you're worried about rust in a stored tank, put in a bit of diesel fuel or gas/oil mix, roll it around once in awhile to keep surfaces coated, and flush the tank in the spring. Re. sealers: I've used Caswell for years (on bikes that get ridden, not garage queens). Flexibility was a concern, so before applying it to a tank for the first time, I mixed some up and lined a gallon plastic yoghurt container with it. Tweaked the plastic much more than any thermal flexing that a metal tank would be exposed to and couldn't crack the liner.

 

[G_YamTech_314]

Yes, do check the valves, and the cam chain tension too. Also inspect the tensioner screw/plunger assembly to make sure the copper damper washer is there. For some reason, they often go missing, and the motor can tick like the valves are loose if it isn't there.

What's the process for checking the cam chain tension? I should REALLY buy a manual for this thing. Is the picture above a picture of the tensioner itself? What spec should I set it to for tension?

 

[5twins]

Yes, get some manuals. You'll need a few since your bike has some newer parts swapped on. Go to the XSCafe web site. They have lots of manuals you can download for free. Your model got quite a few changes compared to the earlier ones. Then even more changes came along on the models right after it. That's why you'll need a couple different manuals to refer to. Your forks and front brake came from a '78 or newer model so wouldn't be covered in a '76 manual. But your carb set, used on the '76-'77 models, wouldn't be covered in a '78 or newer manual.

You will find the cam chain adjustment procedure in the manual. It is presented as a "static" adjustment (motor off). But there's a better and easier way to do it, while the motor idles. You watch the in-out movement of the plunger at the end of the adjuster screw. It should move in and out slightly, about a MM or so. If it doesn't move at all, the adjustment is too tight. If it moves more, the adjustment is too loose. You can experiment with the adjustment setting as the motor sits there idling. Loosen it way up and the plunger will move more and eventually, the motor will start making noise like loose valves. Tighten it back up and the noise will go away, and the plunger movement will decrease. Tighten it too much and the plunger movement will stop. Many of us tighten the adjuster until the plunger stops or nearly stops moving, then back it out a little bit until we get the small amount of in/out movement we desire.

 

[5twins]

Here's a drawing of the later tensioner types. If stock, you should have a type D assembly on your '76 model, the one without the lock nut .....

You can pull the adjuster screw, spring, and plunger right out of the housing to check for the copper damper washer with no ill effects. No parts will drop off or fall away inside the motor. I'm also going to suggest you put upgrading your type D tensioner to a type E on your "to do" list. The type D assembly doesn't have a lock nut to lock the adjuster in place. The large acorn cover nut acts as the lock nut. Now, I know you've experienced having a bolt spin as you tighten a nut on it, requiring you to hold the bolt. Well, the same thing could happen on this type D adjuster. Every time you put the cover nut back on, you could be making your adjustment tighter. Running the chain too tight will prematurely stretch it out.

 

[Jim]

So, I finally got around to cleaning the tank insides.

Did you use the muriatic acid? If you did, give us some details.... amount used, time soaked, cost.... stuff like that as a reference for others.

 

[G_YamTech_314]

I did use muriatic acid. I bought two gallons. They cost $7.99 a piece at the local hardware store. I just did a 1:1 ratio of acid and water. Since the tank only holds 3 gallons, the 1:1 was more like 2 parts acid to 1.5 parts water. It just doesn't hold the whole 2nd gallon. Either way, it sat for about two hours total. I went outside to change the orientation of the tank and give it a shake every ten or so minutes. Managed to clean it up quite nicely and I found no pinholes. All is well. I got 48 fl-oz of isopropyl alcohol at $2.50 per 16oz bottle.

Before the alcohol I used 1 cup baking soda per gallon of water til the tank was full. I stirred it up and made sure the baking soda mixed well because it will settle more than it dissolves. I shook it up really well and dumped it into a bucket so I could use it to neutralize acid in my yard too. (Oopsies)
I rinsed four times with clean water and then ran as much of the water out as I could. I used all three alcohol bottles to fill it as much as I could. And just shook it well in front of a heater to help evaporate moisture. Flammable? Yes. Did I burn? Nope.
It still ended up flash rusting a bit but I don't think it'll be too much of an issue.

It took a couple hours but it probably would've been done faster for someone less critical than myself. All in all, I think I spent just over $30 for everything and now all I need to do is try and do it again with a smaller amount so that I can properly seal the tank to totally get rid of rust being a factor. Despite really cold weather, I got it done.

 

[G_YamTech_314]

Did some more work on the bike since I last posted. It has now gone through an oil drain. I say drain because I haven't yet added more oil. Giving it some days to really just sit and drip over an old baking pan. (Mainly because I have little time during the week) I will soon be flushing the motor with kerosene and cheap oil. The parts are still shipping... But I'm aiming to see it run, idle, and revv with no gas leaks or sputters (valve clearance is among this process at some point). Then onto testing components, such as: does the motor pass a compression test? If not, how bad is it? Good enough for a season of riding??? Anyways... Enough with my plans. People know how these things go...

WHAT I DID RECENTLY...

I got new filters in the mail. Cleaned the old ones to reuse.



I made a gasket for the sump plate, and thoroughly sanded the mating surface to get all the ole' Indian Head Schlack off of it... Must've leaked and PO thought it was a good idea to half ass it... Correct me on that if I'm wrong but I had to use channel locks to grab the drain bolt and yank back and forth to free the plate from the sump... How they changed the oil properly this way is beyond me...



I also found that the element cover is damaged on one side and I'm wondering if it is an area if concern...

Still awaiting the arrival of the carb parts. And the clutch cable.

How important is the hole that outlines the oil port for the sump gasket? My guess is that any tear can cause oil to bypass the filter allowing more debris into the motor. Should I not use my hand made gasket? Should I just see how it works first? Looking for the best way to do this.

 

[member28833]

YamTech you are going at it ! Cheers

 

[G_YamTech_314]

YamTech you are going at it ! Cheers

I'm trying! Just playing the waiting game with parts is enough to make me crazy...

 

[G_YamTech_314]

BUT WILL IT WORK THOUGH? Just spending some time making up gaskets, and experimenting with a shroud for the sump filter... Will this work? You guys tell me...

 

[G_YamTech_314]

Forgot to attach a picture of the bottom part of it

 

[gggGary]

The mother of all threads on sump filters.

 

[G_YamTech_314]

The mother of all threads on sump filters.

I didn't see anything on that thread about building covers... I'm just wondering if anyone else used a beer/soda can thickness aluminum to support the vulnerable side. I also wanted to he sure I didn't have too many holes and if they are too big. Going to he repairing the filter today, flushing the motor with kerosene, and filling her up with oil. Also reinstalling the rebuild carbs today, and a clutch cable. Gonna be fun.

 

[Brassneck]

This may be too late, but one way to prevent flash rusting after cleaning a tank (and not using a tank liner/epoxy) that I've used fairly well--after the rust has been removed, and you have raw metal exposed, get an aerosol can of WD40, and spray it in every angle you can in the tank...bonus: the mist helps get the tank walls coated and obviously the direction of the spray will coat those areas. Then close the lid and you should be good. Coming back to it a few months later, I've found no rust, and the WD40 still on the walls, etc. I then add a little gas, shake the tank around and poor it out when ready to use. Alternatively, I have at one time forgotten to rinse the WD40 out, and just added gas and the bike ran just fine... I don't think there's enough WD40 to do any damage when mixed with fuel... at least for me, I didn't notice any issues by not rinsing it out.

 

[5twins]

Here's the sump filter guard I made up .....

http://www.xs650.com/threads/sump-filter-guard.52818/

The whole right end of these filters, the area past the magnets, is prone to tearing. The unpleated area on the rear side is what usually goes first, but once you patch that, the stress is simply transferred to other pleated areas of the filter on that end. They'll hold up better and longer, but eventually they may tear out too. So, I covered that whole right end from my patch on the rear to the magnet on the front .....

A tip on patching the torn spot - cover the whole flat screened area, even if it's not torn yet.