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Messages - alexbrown64

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Tech Talk / Re: Coil Ohms Readings
« on: Yesterday at 10:45:21 PM »
Hi Sleepy, that figures..

I have seen that value of 1 Ohm mentioned for the coil that goes to the spark plug.
But that is still confusing as to what the two coil values on the stator plate should be.
I guess the one that is open is definitely knackered as its not returning any value at all.


Tech Talk / Coil Ohms Readings
« on: Yesterday at 06:31:28 PM »
Well, i have absolutely no spark whatsoever on my little YZ80E.
It has the outer rotor style magneto assembly.
The Yamaha book i have for the year says the  Primary coil should be 1.0 Ohms
The secondary coil should be 5.9K Ohms.  And it doesnt mention a value for the tiny pulser coil.

I have uploaded a pic (below).

The exploded view diagrams online refer to both the larger coils as source coils.
I am getting about 359 Ohms through the brown wire which leads to the biggest coil.
I am getting nothing through the smaller coil which has a red lead. No Ohms and it seems to test as an open circuit.
I am getting about 9.9 Ohms through the pulser coil which is a white lead with an orange stripe.
I have tested the smaller coil lead right back from the plug to the coil, and i get a reading that the cable is OK.

So, my questions to all you guru's is... Which coil is primary and which is secondary?
I could replace the smaller coil with the red wire, but do the other values sound correct?



Yamaha / Re: YZ125G stator winding resistance.
« on: July 17, 2018, 11:04:06 PM »
Funny how you can get focused on one thing... Good to see some alternate documentation that confirms the different reading to the manual.
As for the projectyz.. it also convinced me to start on mine. 
Hope to kickstart my 12G project again soon..


Yamaha / Re: 1978 YZ80E Rebuild
« on: July 13, 2018, 11:47:53 AM »
Crotch Rocket Factory also made a hopped up version of the YZ80E.


Yamaha / Re: 1978 YZ80E Rebuild
« on: July 12, 2018, 11:25:03 PM »

Just received the 14" chrome rim from Partzilla.  Fantastic quality rim and would be perfect for the rebuild.. but has D.I.D. Made In Indonesia stamped on the side.  The YZ rims were Takasago and made in japan and had it stamped on the top near the nipples.  Both my YZ80's have original rims, so its off to the chrome platers at great expense..

DG had a lot of hop up parts for these bikes back in the day. Rocketfrog has an E with some great DG parts and i hope this brochure give inspiration for a build..

Ive just about got all my parts now.  Nearly everything except plastics.  Still a lot of straightening, cleaning, cutting, heating, grinding, molding, sanding, blasting, powdercoating, zinc coating, 2k painting etc.. to go but i am on track.  Should be a year or so and hopefully have an E i can sit back and look at and remember when i was 13...


Yamaha / Re: 1979 YZ80F
« on: July 08, 2018, 06:25:56 PM »
Yep Husky/Rocket, I think the E/F can look and run great as those DG package racers. I guy called Ron Boucher (I think) on Facebook and Vitalmx sells hop up parts for them.
My E and F are going back to original....not concourse, but clean.

Thanks for getting the seat foam set up through DC Rocket. I bought two. The E/F have the same shape on top, but the seat bases were slightly differently molded, but will fit both bikes.
I have a nos F seat cover to go on. The E seat cover is new replica from Canada. It has the piping like the original. The Thai ones don't have the piping.

The problem with the E was the cheesy frame. I have the Yamaha gusset kit I will TIG on. I will take pics of the frame restore. One rare item I found was the wire looking front brake cable guide. Also, I found nos front number plate wire mounting hooks and rubber band..

I think the E is a great bike to do up as a project. You should get yours up and started Rocket, as a DG racer would be worth a lot of money, and look great. I would love to see some pics of that.

My collection of parts is almost complete for the E, except for plastics. I may take my 125G, 80E and 80F hardware to the zincers to get done as a batch.  Then take all the frames, hubs, motors etc to the powder coaters to get done as a batch.


Yamaha / Re: 125 G-Banger Project
« on: June 27, 2018, 06:30:54 PM »
Great info there baitfish.  Looks like you certainly have your work cut out for you getting G-Banger going..
I have to split the cases on my G, but hopefully all is well, as a few months ago when i bought her, i got it running and took it for a test spin up the street.  Was lifting the front wheel through the gears... Absolute flyer.


Yamaha / Re: 1979 YZ80F
« on: June 26, 2018, 11:07:03 PM »
I get my YZ80F workshop manual, but its not a workshop manual. Its a guide that mostly shows the difference between the E and the F.  Its interesting because many believe that the E and F parts are the same.  Reading this book shows that almost all parts on the two bikes are different.

The airboxes are indeed different...

The cylinders and cylinder heads are also different..

Other things that are different are the exhaust pipes, tank mount, seat base, right side engine cover, ignition, bars, levers, transmission, frame pegs, brake lever, front wheel (F has larger spokes), swingarm, swingarm seal guard, front and rear suspension (forks go from 27mm to 30mm), rear mudguard, throttle.

So, as i am rebuilding both models, and they look pretty much the same, Yamaha totally revised the model and not much really is compatible between the two models.


Yamaha / Re: YZ125G stator winding resistance.
« on: June 26, 2018, 06:12:38 PM »
Hi Baitfish.. you should put some pics up of how everything is going.
My G project has stalled a whisker due to so many other projects.. but i still have big plans for her.

I have a brand new Yamaha YZ125G factory workshop manual printed in 1980.
Here is the page on the electrical specifications as described by Yamaha. Hope this helps,

Honda / Re: New XR75 K1 1974 Project
« on: June 24, 2018, 06:53:06 PM »
Cheers,   and not only did it come up quite nicely, she runs well too.
Connected up the fuel line, added some juice and she fired right up.  The lad took her for a blast in the park and run her through the gears.  Everything runs as smooth as silk.  Clutch, gears, brakes feel like new.  Bloody Honda's are bullet proof..


Honda / Re: New XR75 K1 1974 Project
« on: June 23, 2018, 02:18:40 PM »
Almost finished the bike this morning. Got all the panels fitted back up and a new fuel petcock fitted to the tank and tested for leaks.
Only the fuel hose has to be connected and she will be ready to fire up.  That's for tomorrow morning when we have family coming over and it would be nice for everyone to have a rap around the park on the old girl.

But for now, it was time to take get her out for some pics....

This is how we got her last year.. very sad.  None runner, snapped peg mounts, welded gear lever and just about everything rusted, worn, missing, leaking, broken and neglected.  We decided not to do a full rebuild.  Rather, get her running, then strip her down and clean, replace, paint, adjust and give her a birthday so she can live to ride another day.

This morning, the sun was out, and the bike took on a new lease of life.  Even the neighbor came out to have a chat and admire the old girl..

A lot of parts were sourced as genuine Honda parts from Partzilla..

A lot of parts were sourced from Re-Mx, who do a lot of genuine and reproduction stuff for Honda mini bikes..
Some stuff was sourced from, who do a lot of power pipes and stuff..

The paint was matched with the rear mudguard that was under the seat and still had some perfect paint.  There is a hint of green in the metallic grey.  The panels are 2k clear coated to protect them.  Some of the decals are genuine Honda, and some are replica from fastguystuff and re-mx..

Rather than paint the engine, we decided to polish it all up.  We had to take the engine covers off anyway to replace the gear shaft and some seals and gaskets, so the buffing wheel was used then..

The forks were rebuilt with new oil and seals and then buffed. Sadly, the original rims were badly scratched up. They have been kept, but aftermarket ones from Thailand were sourced along with the spokes and nipples.

Levers, switch gear, throttle, grips etc.. are all original Honda. You can still source the rubber doohickies for the ends of the levers..

Warning decals are correct size, type and location.  My old tank still had the marks where the old decals had been.  Also, the tank still had the original Honda wings on, so the location was measured and the new ones replaced exactly in the original location....

Aftermarket petcock is exact Honda replica.. and works perfectly. New reproduction shaped seat foam for the 74 was from DC Plastics. Thats a 74 seat cover on there.  The alloy engine mounts are from the same company who makes the power pipes..

And thats about it for now... hopefully pics to come of the old girl running.  Then hopefully the boy will be riding her in a few VMX meetings just for a bit of fun.  The old girl is not ready to fully retire yet!!


Honda / Re: New XR75 K1 1974 Project
« on: June 22, 2018, 04:44:35 PM »
Hi Tony,

Yep, Dixon rd, one of the tool places. Was on special when i got it. Seems to work good, and it comes with bunch of attachments for soldering and plastic welding.  Just gotta practice on some scrap first.  Even  comes with a bunch of plastic rods in black and white for a variety of different plastics... abs, pe etc..


Honda / Re: New XR75 K1 1974 Project
« on: June 22, 2018, 09:21:57 AM »
3 tyre levers ??? >:( bloody cheats!
Yep, im going the full Monty...

The black guard that sits under the seat and helps support the main mudguard on the XR had a 75mm crack in it.
I had my Kingchrome plastic welder up on the shelf which i hadnt used before.  I got it out early this morning and read the instructions with a cup of coffee.. then got cracking.
I made a v prep in the crack and cleaned up the area.
I filled the welder with gas, fitted the weld nozzle and turned it on to heat up.
I selected the provided black plastic polyethelene weld rod and inserted it in the hole
I had the heat up too high so the rod melted all over the hole.
Turned machine down and proceeded to weld.  Works well when you get the technique right.
It will need sanding down and cleaning up a bit, but should be all good to provide another 45 years of service.

I have a lot of other parts that need welding.  I have bought a bunch of coloured rods on Ebay, so hopefully i can get my money's worth out of it.


Tech Talk / Re: Metal Filler
« on: June 21, 2018, 05:09:14 PM »
Yep, Devcon is used in Alcoa to repair all sorts of worn steel.  Strong industrial two part stuff.  Expensive, but good quality.

Honda / Re: New XR75 K1 1974 Project
« on: June 21, 2018, 03:47:14 PM »
Thanks for the link... it gave me inspiration to try again.
I have had my technique all wrong.  I used baby powder, but no Windex on the outside.  I only have two manky tyre levers instead of 3 good ones.  And im not doing it correctly.
I just bought 3 spoons, rim savers  and one of those bead doo dads..
So yes Husky, i will knock back a couple of frosties and give it another go..

On another note, the XR is off the bench and rolling around the workshop.  I fitted the rear brake lever and got everything adjusted up nicely.  Cut the new chain to size and fitted it up and adjusted the slack. Adjusted all the levers like clutch, throttle and front brake so that everything feels nice.  Had to do a few mods to the exhaust and handlebar clamps to get them all fitted and working properly.
Then i had a go at the kickstart.  Its 45 years old, and if you had been kicked as many times as this chunk of metal, then you would probably be in as bad condition.  It ended up being the shaft was worn, so i tig welded a bit of meat onto it and ground it back.  New rubber, new locking bolt and she worked and felt like it was only 30.

There is a black plastic mudguard that goes under the back seat of the XR and helps hold the main mudguard in position.  It has a crack, so the mudguard that sticks over the back wheel kept drooping down.  I have to plastic weld that up and refit it.  Then, if the weather comes good, i can put the clear on the panels, install the tank petcock and fit the last of the stuff on.  A good nudge, and i could be a day away from firing her up..


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