Fast Taker Secaha - a blog

Hopefully, I'll have time to keep posting after the bike is done too

 

That's really nice work!! Keep posting .... really good pics and commentary!

 

Thanks!

I got the crankcase oil seals problem solved by Len, so the engine assembly will progress once JB Weld arrives + I get the two stripped bolt threads fixed.

Meanwhile, today, a friend will be helping me with painting the tank with this

While that dries, I have to start on the forks :roll:

 

The tank actually turned out well. I was hoping for a glossy paint, but I think the lack of it makes the bike look more angry...

 

And now for the forks... I found the two thin washers on the oil lock valve assembly were busted. The oil and gunk suggests the forks haven't been seen to for years (okay, I'm responsible for two of them ), and the hex bolt in the bottom of one fork got busted. Luckily, no pitting or rust detected on the inner tubes, though the c-clip beneath the dust seals were rusted out. Oh, and I've forgotten to order the inner oil seals, so go figure...

 

Very nice work!

 

Why, thank you!

Currently in the need to source shim washers for the forks bottom valve. They may even be hard for Chacal to find (though hopefully not)...
Once I got the inner tube out, all but 1 of the original washers were "alive"...

 

Finally got some more pictures to put up. Actually got to do a lot of work during the last few days...







Next up is the bar mount MC with horizontal reservoir. This does not work if you want to keep the original RH switches. Even if you do, like I've pictured below, you need to cut the lever bracket from the existing switches.



A point ot check when troubleshooting faulty blinkers, is the switch internals. I had problems with the right blinkers not engaging towards the end of last season. When I opened up the switch, I noticed the two prongs were bent just slightly out of reach for the lever. Solution: bend them inwards.



Finally the frame is on the assembly table. Got the center stand, side stand with stwitch, triple T and crown, bars, and the switches on. Ordering alternate RH switch with throttle slider today.

 

Good work, good choice of colors. You might think about a pin stripe on the tank, maybe a brushed aluminum silver, light but not shiny. 8)

 

Thanks! I'm considering the triple racing stripes (white-black-grey) on the sides, but since the red is so little compared to the rest, I don't want it to be too obstructed... for now

 

We're getting along nicely in the garage, and engine assembly is imminent. While assembling the engine, however, I came across this on the gears:



You can see the notches on the 3rd gear, and a veeeeery slight marking on the 4th gear.
I'd like some opinions on how these can have occurred. I did replace a 3 part primary chain guide. Any other guesses?

Also in the assembly process, I'm stumped to find that I no longer remember where this assy belongs. I do remember something about the oil cooler joint (between engine and oil filter), but no more than that...

 

Solved the oil distribution block assy problem with a thread from February this year...

http://www.xjbikes.com/Forums/viewtopic/t=35818/highlight=oil+cooler.html

Also got another picture of the pittings on the gears:



And here is the mock assembly of the bike so far:

 

theres beer in that glass. needs to be fixed

love the paint choice on the tank

 

Sorry dude, had to change the picture with a hires one :lol:
Rest assured that the beer went to a better place...



I'm facing a conundrum here... The part you see in red was in the same ziplock bag as parts for the clutch, but I can't seem to place it anywhere in the clutch assy. I did check both factory and Haynes books, as well as fiches for the XJ750RK...
Also, the part circled in blue is a bit of a mystery, as I'm sure it came out with the shifter cover. Same here, I can't seem to find it in my fiche...

 

The red ringed spacer collar has probably found its place.
I suspect I forgot to put it in the right bin during teardown, and believe it belongs on the rear shifter arm.
Also, the blue ringed part goes into the clutch cover.
That's what you get for posting before looking at the fiches again

However, here are my woes about the wiring:

- Too many wires that could have been simplified
- Wires from the handlebars go way back under the tank?!!!
- Wires from the speedo could have been made a little shorter, thus saving a lot of space in the headlight bucket
- Some splices could have been done in much more space saving ways
- The connectors, don't get me started on those...

 

Some more work done. Third take on molding a front fender in fibre glass worked! In true sci-fi style, some may say it looks like the head from Alien...







There are some clearance issues. Seems like the filler material made the fibre glass bend a little on the tail, causing it to crawl ever so slightly to the right of the front wheel. I suspect some washers on the right side might just move it back. You can even see the anti-dive block-off plates. They're temporary, I just need to see if they can handle the pressure.

The engine is coming along nicely. I thought I was dead when I lost two of the piston rod springs into the engine, but luckily they came out when we turned it upside down.
The handlebars I ordered a month ago are still in transit, stuck at F****** Hamburg.
I also ordered a full set of wires, and will try to make another harness when time permits.
+ somewhere along the line, I want to put in hazard lights to ease riding on the strip in rush hour.

 

Coming along nicely! Guard is definately of alien origin! I like it!

 

Since last post, I've gotten the engine pretty much assembled. However, the timing chain is giving me headache. It's brand new, and thus very tight.
I agree with Len, in that it's probably not a good idea to attempt to stretch the chain before insertion.

But I think I may have come up with a solution.

I already have a valve shim tool, but I've ordered another to hold down two valves at a time, where normally the lobes would have touched. I'm hoping this will give me lobe room to rotate the cam sprockets one at a time while they're off the cams...

Stay tuned...

 

I like it, you've done a good job. I also like the paint on the tank.

 

Thanks alot! Still haven't gotten around to taking a hidef picture of the tank after varnishing. The previously dulled Red is now bright and shiny...

 

Take a look at the tank now...

 

Nice!

 

Thanks!

I've been away on vacation for some time, and when I came back I simply didn't have the motivation to pick things up.
That's all changed now. I've taken the engine apart for the second time, and already gotten most of the gears into the upper crank case.

However, I'm still struggling with a problem I encountered last time - namely that one or two of the rods are sticking to the crank when I torque them up (as low as 7,2). There's just no way I can get to the specified amount of 18,1...

 

It's been a week of dismantling and reassembling the engine.

I did manage to solve the sticky rods. It turns out that the small lip on the connecting rod plane bearings have to face each other upon assembly. Only then would they allow full torque.

From then on, sealing the engine casings was a breeze. On with the covers etc. All the way to the cams. And that's where the problems started to develop...

You see, the timing chain is brand new and really tight. However, it was easy enough getting both cams on. BUT, once both cams are on, chain guides in, chain auto tensioner in, and everything is torqued in place - suddenly, you can't turn the engine over using tools. Not on the crank, and not on the cams.

If you try to turn the engine over using a wrench on the cams, it puts an unnatural strain on the chain because that's not the proper way to transfer power. And if you try to turn over the engine on the crank pick-up rotor, it puts such a strain onto the rotor itself that you rick damaging the rotor.

The only solution I can think about right now, is to run the starter motor to engage the engine (also in the correct direction of rotation). But I thought I might put the idea up for slaughter here first...

Thanks for reading, this has been a report from a long overdue project.

 

It was a while ago that I did this, but I do remember having a lot of difficulty setting the timing - it took a lot of force on the chain to get the timing marks on the sprockets to align, and then the motor didn't want to budge. Eventually by slackening the sprockets and tensioner, turning the engine over repeatedly, and then retightening, I guess I managed to work the chain into a position that both aligned correctly and turned smoothly.

Of course, I was reusing the old chain, the situation might be different with a new chain. Hope this makes sense, the bike runs pretty good now... if anyone knows better please chime in!

 

Thanks for the word.
I want to get the head off again, to check if the valves are sticking. They should not, but they might...

 

Finally got sime time to spend on the bike yesterday. Took off the chain auto-tensioner, the cams, and valve head, in the hope that the reason I couldn't get the cams to turn may have been caused by misalignment of the timing mark.
Tried to set the 1-4 pistons to TDC and put everything back together. When time allows, I'll bolt the cams up and try turning over the engine some more...

I set the marks pointing perpendicular to the cams, but are they supposed to point up in another way?

 

After tinkering with the engine some more, I seem to have come to another dead end, at least from the looks of it.
I got the cam spots to align with the cam cap marker, but the the timing wheel won't end up in a spot near the timing mark.
Any winged words from the congregation on this?
Also checked the valve shims, and only need to replace one 260mm...


These look good...


The T-mark does not align...

 

Had some spare time on the bike yesterday, and finally got the marks all aligned. Even did a new TDC check, and moved the timing wheel down by about 10 degrees.
This is a major breakthrough. I felt really down during the time I was struggling to get the timing right. But now I'm full of energy again, and will continue to put her together the coming weeks. Might even get a ride before the snow falls

 

I give thee a photograph of the complete (almost) engine. I also had some help in getting it into the engine. I assumed it would be much easier to get it in if the swing arm was removed, and I was right. Total time spent was 10-15 minutes...

 

And now; swingarm, handlebars, and rear shocks on frame.

 

Bought a new battery, as the old one wouldn't hold charge.
Same producer, same model. But the new one came without threaded plugs, so I had to strip the battery sensor of threads...

 

I've had some quality time with the bike past month, securing the exhaust and rear blinkers.

Currently working on wet-setting the carbs, where I've discovered a somewhat easy ratio to go by.
We all know that the level of fuel in the bowls is directly related to the position of the fuel valve holders on the floats. I wanted to see if this could be done a bit more scientifically, and seem to have come up with a number that equals 0 +/- 3mm of fuel in the bowls.
Take a look at the picture below. The passage for the float holder pin has an OD of 4,5mm. When I eliminate other possible causes of error (such as bent metal etc.) and set the vave holder to 4,5 mm, fuel in the bowl magically ends up at close to 0 mm in the bowl.
This is working for me and I'm sticking by it, but if anyone else has time to check if it applies to their models as well, it would be greatly appreciated.

 

I see that I haven't updated this in a while, so here goes...

The method described in the post above works out really well. All float bowls are now zeroed in!

Got the cut airbox in without much of a fight, and it got me thinking if Yamaha should have designed it in a way that the air filter also served as an air flow constrictor. Would ease any work done, as well as saving space.

You can see some crappy photos:

 

After installing new clutch springs, it seems they're too hard for the clutch lever to handle. I managed to strip the clutch handle and handlebar clutch adjuster...

Time for Ebay again...

 

Small update of progress (I think)...

Some of you may have seen that I had some trouble with a RH switch. More on that here: http://xjbikes.com/Forums/viewtopic/t=42052.html

The original clutch seems to work now, even though I thought the threads had been worn due to new springs. Still need to adjust it somewhat, as new springs + new friction plates make the clutch hug harder than before. Enough so that the pull is not enough to release the rear wheel in gear.

So, back to the wiring. I found that I had wired to sockets wrong and corrected them.
And although I can't see it on the wiring sheet, there seem to be two spliced Dg (dark green) and two spliced Brown (Br) wires coming from the right side main harness. I'm assuming these may be for hazard lights, but any other input is welcome. The connectors are now wired the way they were before I took the bike apart.

Also, some electrical gremlins are present....
When I put the ignition to PARK, I get lights in the gauges and the fog light comes on. Will try to pull the ignition and switch the location of the circuit breaker cross inside and see if that helps.

If that is not related to my problem, check out the ghosts:
- Key turned to ON, seemingly normal light-up
- Engine kill switch ON, instruments indicator lights comes on
- Headlight ON, instruments turn off, break light comes on
- Fog light never comes on
- Indicators turned to either way, correct rear light comes on and stays on
- Indicators turned to either way, front indicators never come on
- Key turned to PARK, instrument lights and the fog light comes on

 

Just saw this thread, as you bumped it, and like it very much. The look and paint is very nice.

 

Thanks! I'm really happy with the paint on this one. Can't say that I'm fixing it for selling as it was my first project. This one's a keeper!

 

What loom are you using, seca with computer?

What model is it, really 1984? Which country? 8O

Could possibly be crossed wires somewhere in the right switchgear (my diagrams (using UK 750 for now) shows 4 wires for lighting, red/yellow & blue operate park/tail/instrument lighting and yellow & blue/black operates headlamp low/high beam.

In the main switch there are 6 wires shown, (red, brown, blue, blue/red, white/red & another white/red) the only pair joined when switch is in park are red & blue/red.

EDIT-: There could be more than one fault but I'd check this out first.-> There is a diode shown near the computer with the blue/red and a blue wire, which stops the park position from lighting the instruments. Perhaps this diode is bad or missing?
Hopefully this is of some help, but if your wiring is different & you can post a diagram I could have a look for you...

 

I see im not the only one who thinks two seca 's are better than 1

 

Posted the UK diagram as that one seemed to fit the bike best. It's an RK 11m, but the wiring is definitely like the UK version, registered in in Norway first time in 1984.

Forgot to write that that I've unplugged the lighting wires from the switchgear to harness. I also tested rotating the cross inside the ignition to no avail. That just made the R/W wires (for battery sensor) go dark.

 

OK so the diagram I was referring to (as it seemed closest to your wire decriptions) is also the UK 750 one so we're on the "same page" as it were.

Check the diode near the computer that I put in bold in the last post (blue/red and blue wires) as this could be the problem with the instruments lighting up with switch in park.

Looks like on other models including the RK, the instruments are supposed to light up which is strange (personally I believe the RK diagram is wrong since the tacho is shown getting it's light powered from the neutral lamp!), but if yours has the diode like UK models that's my favourite to cause the fault.

 

Just another thing that may cause confusion is on some diagrams the 9 pin connector to the computer has one empty slot & on others it has a black earth wire to it. If you have a missing earth from that it could be a problem.

Test the diode first though & then if you still have a problem please can you post pics of both computer multiplugs & both sockets in the back of the computer?

 

Will do!
Mind you, I have not done any alterations to the harness, apart from trying to hook a 3-wire light switch to it. So, if there were a ground on the 9-pin connector, it's still there.
I did test the diode with a multimeter, and discovered that it works only one way. Is there another test to be done?

 

Diodes are designed to pass current only one way. ThEy should block current in the opposite direction. I think that's the only test that matters, so it's probably good.

 

Hang on, these faults have only appeared since you played with the light switch wiring?

I thought you left the 3 wire switch out as I said it wouldn't work?

How have you got the light switch wired at the moment?

 

Ah, The UK diagram we've been looking at has a different setup on the main switch to the RK (and the RK has fog lamp where UK does not). Using the UK diagram could have caused some problems...

I need to know now, what exact wires do you have at the main switch?

If you have 5 wires as per RK then the park position joins red to blue/red,

BUT if it's the 6 wire UK setup then the red wire needs to have continuity to solid blue in park...

 

I did take out the 3-wire switch. I was just commenting that I haven't done any alterations to the harness besides that, in connection with your comment on the 9-pin wire.

 

OK no problem, just have a quick look at your main switch wiring. I spotted a possible problem with using the UK diagram for your bike. The RK diagram has a different main switch setup. Will try stick to the RK for now as it should fit better, but I'm worried there's errors in it :?

Let me know what wires you have in main switch & I'll tell you which wires should connect in "park" & in "on". An incorrect park wire here could cause the problem too I think

EDIT-: by the way, you saw 2 spliced wires (dark green & dark brown). These could well be the front indicator wires, but let's get the main switch & park problem sorted first

 

Fouuuuuund the culprit. It was me! I stupidly forgot that the stock MC has a level sensor. Since I've swapped it out for a bar mount mc, I'd forgotten to run that wire to ground. Also, the front blinkers do indeed run to the spliced Dg and Br wires. Just the blinking and headlight left.