Just another first build.

yamamunn said:

nice build. I have 78 650 special in the middle of rebuild. Do you do your own PC as there is a bit done on your build. I PC'ed my frame, tank, front and rear fenders, air boxes, motor mounts, mag wheels but left the original parts polished, cases and lower crank halves,lower forks,discs were drilled and PC in the center,triple clamps,tach & speedo. Still have to finish assembly of the motor should be ready for some spring rides. Heading to Florida next week with my son for a week for some MX

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Thank you! Nope I do not. I sure wish I did though! Would've saved me a lot of bills. Do you have a build thread going? Would like to check it out if you do.

Sweet! There's one track in Florida I've always wanted to ride. I think it's called dreamland or something like that. It may be private. I've seen videos of it and it looks incredible! Hope you and your boy have a great time.

Finally have a kickstand!!! Haha I'm so stoked to have it sit on its own weight. The blocks were such a PITA.

That spring is gnarly by the way.




Found a rubber vaccum plug that fits over the barb perfectly. does it need to be hose clamped?



Also found some thinner 1/4" fuel line.



Waiting on exhaust and order from Mikes....

Love the seat! No good here in London though, would be ruined in no time!

Dang your bike is looking great Rd51. She ought to be a fun ride man!
That rubber plug should be fine without a clamp, that's the way I'm running mine.

Moar Pics!

Some more parts showed up on friday.

Clutch lever and pertch installed. Cable is hooked up. Still need to adjust the clutch properly.



Master cylinder showed up. I hooked up the brake switches for the front and rear brake tonight. The only wires left to do now are the wires for Hugh's PMA.

I'll be having a stainless brake line made up this week.



New petcocks installed.



Saturday I dove into tuning this thing. I got the correct pilot jets for these carbs from 650 central, still size 30. I also got the air barbs that screw into the side of the carbuerator so I could sync the carbs. I raised the clip (lowered the needle) one slot. So right now the carbs are as follows:

Main: 140
Pilot: 130
Needle: Third slot from the bottom
Air screw: 2.5 turns out (the right carbeuator was turned almost all the way in)
Floats: 24mm

So this is how the timing was set On saturday. It's a little difficult to see in the video, but here it is.


Bill let me borrrow his old school manometer (still uses mercury)



So I thought everything would be dialed in. Starts right up first kick. But the idle was still hovering when I let of the throttle. I called it a day and went home and started reading some more.

Fast forward to tonight. I read that the idle could be hovering because of the mixure screw being off. Checked the left carb, it was good. Checked the right carb, it was turned in almost all the way. so I set both at 2.5 turns out. Fired it up.

The idle seems to be slower than it was on saturday. When I rev it up now, the idle isnt hovering. It sounds pretty good, BUT, I noticed the right exhaust pipe is backfiring (shooting a small flame) out now. I did not notice that on saturday while tuning.

Pulled out the timing light again, and it's off. It's not set how it was in the above video. It's firing closer towards the TDC mark. Maybe I bumped it while tightening down the hold down screws for the PAMCO?

Here's the left spark plug to date



Right side spark plug to date



I'm speculating the ride side plug looks the way it does because of the mixture screw being turned in all the way? Any one else have any ideas?

My plan of attack now is:

1. Pull carbs (gaskets are leaking anyways) Clean all passageways thoroughly again. check float heights again. Clean all jets.

2. Re-adjust timing. I'm thinking this is also a part of the problem along with the mixture screw.

3. Carb sync again, because I'll be re-adjusting the timing.

4. Check exhaust gaskets, make sure pipes are in tight.

5. Check to make sure carb holders are not leaking air. I don't really see how they could, since they are brand new and hose clamped

When it comes to the timing; does the bike need to be idling at a specific RPM?

I'll get going on the above plan. If anyone has any other info let me know please!

Soaking up some rays. I can't wait to get the pipes from Gordon on there.

Rd51, Your bike is looking great. I'm jealous, I haven't had a chance to even touch mine in over a month. Oh well. Hey I'm curious about who's master cylinder you are using. I like the clean look. Thanks mang. Captain Fun out.

They way I read up on tuning the air / fuel adjustment screw is
With engine running
1) Set the idle low by adjusting the air or fuel adjustment screw
2) Give it some gas - If there is no delay
3) Increase idle by adjusting screw.
4) Give it some gas.
Continue doing this until you hear a delay in your throttle response. Then back the adjustment screw off to the previous tested position.

Damn man. Looking good!!!

Captain Fun said:

Rd51, Your bike is looking great. I'm jealous, I haven't had a chance to even touch mine in over a month. Oh well. Hey I'm curious about who's master cylinder you are using. I like the clean look. Thanks mang. Captain Fun out.

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Thanks man! On mikes website under the master cylinder section, it is part number 08-0255. The front brake lever is a little longer than I was looking for. But it will do

Kathos said:

They way I read up on tuning the air / fuel adjustment screw is
With engine running
1) Set the idle low by adjusting the air or fuel adjustment screw
2) Give it some gas - If there is no delay
3) Increase idle by adjusting screw.
4) Give it some gas.
Continue doing this until you hear a delay in your throttle response. Then back the adjustment screw off to the previous tested position.

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Kathos, thanks for the feedback! I think I read that somewhere as well. I'll post what I end up doing

Rd51 said:

Thanks man! On mikes website under the master cylinder section, it is part number 08-0255. The front brake lever is a little longer than I was looking for. But it will do

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Coolio, I'll check it out. Thanks.

You're talented man.

JayR said:

You're talented man.

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Dang. Making me tear up over here! Haha thanks though man, really appreciate that.

Got the exhaust back from coating. Decided to leave the tips bare. Wrapped them in titanium exhaust wrap. (I'll post some close up's later)



Here's how "Five One" (creative name, I know ) sits right now. The wrap is a little dark in this picture because it's still wet. I started the bike up tonight to burn the wrap on there. Looks a lot better already. I love how the pipes look and I love the sound as well. Gordon is the man!


I throughly cleaned the carbs, and checked the float heights. Re-installed the carbs. Adjusted the timing so it's between the F marks. Idle isn't hoovering anymore. So that's good. But I still noticed twice a small spark outisde the right side exhaust.

And, the right side carb is leaking fuel I replaced the gaskets on both carbs. But the gaskets must have not been the problem. I guess it's float height? Which I don't understand why. I checked them with no gasket, and the carbs upside down. 24mm (76-79 carbs)


I have a suspision that the igntion isnt advancing correctly. I had the timing light shine on the mark while it was running. It was between the F marks. When I rev the bike up, The mark starts to move forward (away from the TDC mark) but then it'll jump backwards irratically (towards the TDC mark) Is the mark supposed to move in a direct correlation of RPM's? In otherwords, nice and consistent?



Going to spend the majority of the weekend trying to get this thing figured out. As well as installing a new chain and 32T rear sprocket.

Faulty E-Advancer? I recall you fitted a new Hugh's PMA and Pamco ignition. I'm no expert but was doing some research for my bike and Pamco also says If you have a '71 to '79 model, then you will also need a dual output coil, such as www.mikesxs.com part #17-6903 or equivalent with a 2.5 to 4.5 Ohm primary resistance.

OK, now I'm ready for everyone to tell me why I don't know what I'm talking about!

JayR said:

Faulty E-Advancer? I recall you fitted a new Hugh's PMA and Pamco ignition. I'm no expert but was doing some research for my bike and Pamco also says If you have a '71 to '79 model, then you will also need a dual output coil, such as www.mikesxs.com part #17-6903 or equivalent with a 2.5 to 4.5 Ohm primary resistance.

OK, now I'm ready for everyone to tell me why I don't know what I'm talking about!

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I'm using the mechanical advance mechanism still, and I haven't installed hughs PMA yet
I'm waiting to install the pma until I'm satisfied the timing is perfect! If that's possible...

I have a dual output coil as well, and last time I checked I'm getting a spark on both plugs

Take carbs off. clean. Install. Test run. Take carbs off. clean. Test run. Check timing. Check advance. Take carbs off. Clean. Clean. Clean.

Only been a week and this tuning stuff is driving me crazy! Just want to ride already!

I think I'm going to start another thread specifically for getting this thing dialed in tuning wise.


Here's my modified anchor rod for the rear drum brake.







Clears the tire perfectly now. I may leave it bare. It looks good next to the shiny stainless on the muffler tip!

New chain installed. 530 type. Was relieved to see that it doesn't rub on the swingarm after installing the 32T sprocket.



Close up of exhuast wrap as promised.





The REAL culprit to that pesky fuel leak! Switched out the hose with a new piece. all good.



This still confuses me...



and two videos. I was playing with the timing, fuel mixture screws, and idle adjustment screw today.

In the first video, you can see (maybe) where the timing mark was firing. After I rev'd the bike up a couple times, the timing mark was in a more advanced posistion?



In the second video you can hear how much different the idle sounds. a lot slower. I think thats a step in the right direction. But, you can hear when I crack the throttle and hold it there steadily (about 1/4 throttle) the mufflers start making loud popping noises; backfiring. I Think I need to go up one more on the pilot. And possibly, return the needle clip to it's original posistion.



I'm thinking what I need to do is ride the bike, however. That way I can really feel how the bike is running, and go from there.

But, I can't. I havent installed the PMA from Hugh yet. I was under the impression I needed to set the timing with the stock rotor before upgrading. But re-reading the instructions, as long as I install the PMA and keep the engine at TDC and make a timing mark on the new magnet, I can adjust the timing with the PMA from Hugh on the bike.

Correct?!

lovin the look of the bike RD but most of all I'm so impressed at your meticulous attention to everything.

I can't understand why some of us seem to have all sorts of problems getting the tuning right and others seem to dial it in first time around. ? especially considering your critical eye and attention to detail ?

I'm beginning to wonder how the dealerships ever sold these things in such numbers ?
The carbs seem to be turning out to be akin to that other Prince of Darkness 'Lucas' (quickly makes sign of cross)

I think starting another thread to deal with the tuning aspect is an excellent idea ,it could become a useful source of reference for others if the rest of your build is anything to go by.

Rd51 you may want to ping Hugh regarding the PMA / Timing question. At the end of his PMA install instructions he writes:
"As always, if you have purchased a Genuine HHB product, and need help/advice/wanna just shoot the bull, shoot us an email at HughsHandBuilt@gmail.com and we'll take care you you."