Author Topic: CB750K 'Sport Tourer' (Read 23661 times)

knottedknickers · « **Reply #75 on:** July 21, 2015, 07:10:10 AM »

Hung the carbs on the weekend. The rubber boots were a bit hard, but I haven't been able to find any wintergreen to use to soften them... Anyone know of a different option?

calj737 · « **Reply #76 on:** July 21, 2015, 07:17:24 AM »

Try peanut oil

danyo · « **Reply #77 on:** July 21, 2015, 07:22:20 AM »

^^^ just if you don't have peanut allergies

Sent from my SM-N900T using Tapatalk

knottedknickers · « **Reply #78 on:** July 21, 2015, 07:32:00 AM »

Quote from: calj737 on July 21, 2015, 07:17:24 AM

Try peanut oil

Soak? Scrub? Heat?

70CB750 · « **Reply #79 on:** July 21, 2015, 07:43:49 AM »

Quote from: knottedknickers on July 21, 2015, 07:10:10 AM

Hung the carbs on the weekend. The rubber boots were a bit hard, but I haven't been able to find any wintergreen to use to soften them... Anyone know of a different option?

Easier and cheaper to replace carb boots instead of getting into the alchemy of softening them.

My $0.02 only of course

knottedknickers · « **Reply #80 on:** July 21, 2015, 08:57:30 AM »

Quote from: 70CB750 on July 21, 2015, 07:43:49 AM

Easier and cheaper to replace carb boots instead of getting into the alchemy of softening them.

My $0.02 only of course

Perhaps, but not nearly as fun!

Nor as cheap (I'm guessing they're more than $0.02, especially given the state of the Canadian dollar these days). But then the oil is going to cost something... Nothing's free.

70CB750 · « **Reply #81 on:** July 21, 2015, 09:00:07 AM »

With new rubbers you eliminate the option of vacuum leaks, one less thing to chase down.

knottedknickers · « **Reply #82 on:** July 21, 2015, 10:51:40 AM »

Quote from: 70CB750 on July 21, 2015, 09:00:07 AM

With new rubbers you eliminate the option of vacuum leaks, one less thing to chase down.

I'm hoping I can do that with re-newed rubbers...

But I'll keep the possibility of vacuum leaks from the rubbers in mind if the problem arises. I just can't bring myself to spend ~$100 on them. Yet... $:-\$

Desert-SOHC · « **Reply #83 on:** July 21, 2015, 02:26:24 PM »

Quote from: knottedknickers on July 21, 2015, 10:51:40 AM

I'm hoping I can do that with re-newed rubbers... But I'll keep the possibility of vacuum leaks from the rubbers in mind if the problem arises. I just can't bring myself to spend ~$100 on them. Yet... $:-\$

Yeah there not cheap, I had to buy new ones #2 and 3 were cracked beyond repair. The nice part is that the new ones are thinner rubber than the factory and are a little easier to get seated.

knottedknickers · « **Reply #84 on:** July 28, 2015, 07:01:02 AM »

I'm wiring these days... I'm at the three yellow wires coming from the alternator and start to scratch my head.

Which one goes where? Or does it matter? I found this at the bottom of the post:

Quote

And, That Age-Old Question...
...Does it matter which order I connect the yellow wires coming from the alternator to the rectifier? No. There is alternating current being carried by these wires and the diodes in the rectifier take care of sorting out the positive charges from the negative ones.

I'm assuming that's correct?

70CB750 · « **Reply #85 on:** July 28, 2015, 07:11:26 AM »

^^^ Yes

knottedknickers · « **Reply #86 on:** July 28, 2015, 07:19:53 AM »

Quote from: 70CB750 on July 28, 2015, 07:11:26 AM

^^^ Yes

Thanks!

knottedknickers · « **Reply #87 on:** July 28, 2015, 07:34:37 AM »

Found wiring 'gold'! A combination of:

- pages 169-70 in: http://manuals.sohc4.net/cb750k/service_manual/SM750K_5.pdf (Fig. 16-29: wire harness [with every wire identified], and Fig. 16-30: wire harness mounting position)
- page 172 in: http://manuals.sohc4.net/cb750k/service_manual/SM750K_6.pdf (more of a 'physical layout' wiring diagram than the next one)
- http://manuals.sohc4.net/cb750k/technical_reference/WD750K6.pdf (this is a colour wiring diagram for the 750K6; other years available here or via the links at the top of the page)

Maybe referencing this here will help someone else down the road.

Restoration Fan · « **Reply #88 on:** July 28, 2015, 08:47:55 AM »

Quote from: knottedknickers on July 21, 2015, 07:10:10 AM

Hung the carbs on the weekend. The rubber boots were a bit hard, but I haven't been able to find any wintergreen to use to soften them... Anyone know of a different option?

Wintergreen Oil
http://www.bulkapothecary.com/product/essential-oils/pure-therapeutic-grade/wintergreen-essential-oil/?kpid=pla-244&gclid=CjwKEAjw0NytBRD-1d3QsdHNpR0SJACGXqgR0LxB8EMvHWqwlKvNVwrboSzk7TShPiL4y3tnZbbpBRoC3mLw_wcB

This is where I got mine from. You could get the .5 oz option and still have some left over. I went with the 2 oz option and have about 80 or 90% of the bottle still left after doing my carb boots.

knottedknickers · « **Reply #89 on:** July 28, 2015, 08:52:58 AM »

Hey, thanks for chiming in on that! I actually found some at my local pharmacy (a 'behind-the-counter' item in Canada, apparently): 100 mL (3.38 oz) for $5.

What ratio did you mix up? And how long did you boil?

knottedknickers · « **Reply #90 on:** July 30, 2015, 07:56:12 AM »

Does anyone have a good picture (or handy tip) re. the coil clamp for the 750? The front of the coil pack hangs by a bolt through a hole in a flange on the frame (near the bump on a log in a hole in the bottom of the sea...):

But the rear of the coil pack is held in place with a two-part clamp:

It's that bent tab at the end of the clamp that makes it sit 'proud' that has me scratching my head... I don't remember anything being held in there, but it seems really odd for that tab to be there if nothing does go in that gap.

Any tips would be appreciated! Thanks.

754 · « **Reply #91 on:** July 30, 2015, 08:11:23 AM »

The rear clamp ends fit against themselves, and the coil bracket goes against the side of it.
Let the coil bracket find its way from lightly tightening the front, then put the two piece clamp in position.
I can't say however which side of frame the coil bracket should be on.

knottedknickers · « **Reply #92 on:** July 30, 2015, 09:12:05 AM »

Quote from: 754 on July 30, 2015, 08:11:23 AM

The rear clamp ends fit against themselves, and the coil bracket goes against the side of it.
Let the coil bracket find its way from lightly tightening the front, then put the two piece clamp in position.
I can't say however which side of frame the coil bracket should be on.

Ach, zo... It's more of a 'hanger' than a clamp. Makes sense, but I couldn't break out of the box of my own thinking. Thanks!

knottedknickers · « **Reply #93 on:** July 30, 2015, 09:34:10 AM »

Like 754 said above ^^^

Clamp / hanger sits on right side of coils.

Thanks again, 754!

knottedknickers · « **Reply #94 on:** August 03, 2015, 08:46:07 PM »

Mmmmm, Wintergreen!

Started boiling inside on the stove, but soon realized this was an outside job! Moved to the side burner on the bbq. My family thanked me. Boiling this concoction inside for any length of time would have had me sleeping in the chateau de chien for a few days...

I'm pleased with the results. From rock hard to this in 30 minutes:

Well worth the $5 for the Wintergreen.

Unfortunately, the carb-to-airbox rubbers didn't work quite so well... They're much thinner rubber and things happened much faster. I took them out before any visible damage was done, but they hardened back up again fairly soon. I may just leave them to 'cold' soak for a few days. Nothing much to lose, really. They're so hard and shrunken that they don't seal the airbox opening any more.

knottedknickers · « **Reply #95 on:** August 03, 2015, 08:53:41 PM »

I mentioned I hung the carbs the other day, but I hadn't set the float levels. I tackled that this evening.

First, I built a 26 mm gauge:

Pressed it into service:

And had fairly good results:

#2 carb was about 28 mm and #1, 3, & 4 were about 25 mm. Now they're all the same.

While I was at it, I put the back wheel on, along with the chain, chain guard, front sprocket cover, and rear fender.

It's amazing how much more exciting it looks with something round hanging at one end!

I'm still waiting for a front hub from Devin / Cognito Moto. Hopefully that gets shipped this week! Then I can get going on the front end.

Desert-SOHC · « **Reply #96 on:** August 03, 2015, 10:07:34 PM »

Nice!

knottedknickers · « **Reply #97 on:** August 04, 2015, 02:19:10 PM »

Here are dimensions, if anyone's interested in building a float level gauge:

rddcw · « **Reply #98 on:** August 04, 2015, 05:57:34 PM »

What material did you use to build the float gauge? Could you use cardboard?

knottedknickers · « **Reply #99 on:** August 04, 2015, 06:46:21 PM »

Quote from: rddcw on August 04, 2015, 05:57:34 PM

What material did you use to build the float gauge? Could you use cardboard?

I used a plastic lid from an empty hot chocolate tin. It was fairly rigid, but not solid stiff. I cut it with a scissor, if that gives you any idea of its thickness. Cardboard? Like from a cereal box? I guess you could. No reason why not, that I can tell. You just would want to make sure that the edge that sits on the carb body doesn't compress and thereby reduce the 26 mm height that you're wanting to measure. I figured plastic would be more durable on that edge. Not that you're mashing down on it or anything...

One thing you might do different is to make a 26 mm section on both sides, not just one, so that you can measure the height of both floats at once. Just leave a notch in the middle to give clearance for the main jet.

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Author Topic: CB750K 'Sport Tourer' (Read 23661 times)