Author Topic: CB 750 Project 1 - Rides Well but a few tweaks needed (Read 115492 times)

timbo750 · « **Reply #650 on:** October 17, 2016, 02:14:30 AM »

Terry, different bolt, I was referring to the one on the frame tab that creates the return stop.

The good news is the electricals are all now sorted. I knew that standard flasher units - even the electronic ones -don't like LED's but I would not of expected the drop in voltage, it was though the unit was half way through a flash cycle and stopped due to a lack of current draw. But none of that matters as it all works now including the diodes.

There are still a few bolt on bits that need finishing and also the exhaust, then it will be time to fire it up.

Terry in Australia · « **Reply #651 on:** October 17, 2016, 02:52:17 AM »

No worries Tim, I saw the pic of the brake lever sans bolt and assumed that was what you were referring to. Glad you got your wiring sorted. Cheers, Terry.

timbo750 · « **Reply #652 on:** October 20, 2016, 05:11:19 PM »

Getting ready to fit the exhaust and a few other things this weekend so I can hopefully start it up soon. I have an exhaust system that i got with bike, no idea on make or how loud but it will fit for now.

The question I have is that the muffler has no clamp where it fits over the header and it doesn't have a slot so that it can be clamped. Should I just cut a slot and use a suitable exhaust clamp or am I better of welding something directly to it so that it can be clamped.

Terry in Australia · « **Reply #653 on:** October 21, 2016, 02:55:57 AM »

If it's a good fit don't worry about it Tim, a lot of pipes didn't have clamps purely because they didn't need them. The Pipemasters pipe on the cafe racer I'm building doesn't have one for instance, and that's common, they only really need them if they use dissimilar metals, like alloy mufflers on steel headers etc. as long as there's a bracket to bolt your muffler to your frame, that's all you need. Cheers, Terry.

disco · « **Reply #654 on:** October 21, 2016, 03:50:38 AM »

Hi Tim,

Nice project that you've got happening there.

Can you please elaborate on the comment of cutting of the frame a bit further forward? I have a Weldless kit which i will install very soon so want to get it right.

"Yes there is clearance between the carb linkages and the frame kit, but I wish I cut the frame a bit further forward."

timbo750 · « **Reply #655 on:** October 21, 2016, 03:28:31 PM »

Terry, thanks. It is a good fit and is the same material, I just hope its quite enough for a road worthy.

Also can you confirm where the oil vent tubes run. The one from the valve cover goes to the air box and from the rear of the case goes near the chain. Or do they both go the air box.

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timbo750 · « **Reply #656 on:** October 21, 2016, 03:31:26 PM »

Disco. That comment was made before I realised I had the carb boots at the wrong angle causing the carbs to sit about 5mm too high. I would however still put the clamp near the carbs a bit further forward. If you want I can take some photos with more detail and and also put up what measurements I would suggest for next time.

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disco · « **Reply #657 on:** October 21, 2016, 04:01:17 PM »

Hi Timbo,
Some more pics & your reasoning/recommendations would be great.

Terry in Australia · « **Reply #658 on:** October 21, 2016, 11:02:25 PM »

Quote from: timbo750 on October 21, 2016, 03:28:31 PM

Terry, thanks. It is a good fit and is the same material, I just hope its quite enough for a road worthy.

Also can you confirm where the oil vent tubes run. The one from the valve cover goes to the air box and from the rear of the case goes near the chain. Or do they both go the air box.

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Hey Timbo, can you remove the baffle? You can buy fibreglass packing material at some auto parts places, and probably hardware stores and boat shops too? The venting changed a bit as the mighty CB750 evolved, but on my early K1-2's, the rocker cover vent hose actually runs over the top of the air box and just vents to the atmosphere, but the bottom hose runs up into the back of the oil tank. Cheers, Terry.

timbo750 · « **Reply #659 on:** October 21, 2016, 11:15:22 PM »

Terry, thanks. There is no hole for the tube from the rocker cover to go into the air box and I have also people use little vent filters. I didn't expect the tube from the case to the oil tank as they are different sized fittings.

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Terry in Australia · « **Reply #660 on:** October 21, 2016, 11:19:20 PM »

You've either got an early oil tank or a late engine Tim, or vice versa. I have a K6 engine in my K1, the K6 had the bigger fitting, so I had to make an adapter in my lathe so I could have a small dia hose from the back of the oil tank into the adapter, then a larger hose to the engine fitting.

timbo750 · « **Reply #661 on:** October 21, 2016, 11:20:43 PM »

Thanks Terry, I will work out something

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timbo750 · « **Reply #662 on:** October 22, 2016, 08:41:19 PM »

Terry, getting back to the exhaust, the baffle does have 2 screws holding it at the end but I can't get it to move. Must admit I have been a little soft in efforts so I don't damage anything . It almost needs to pulled out but there nothing to grab a hold of.

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maduncle · « **Reply #663 on:** October 22, 2016, 09:40:31 PM »

Tim, can you put the muffler end down on a piece of carpet or some rags and give it a good (but not to hard) tap down onto the carpet/rags? I have done that a couple of times to free up a sticky baffle and get it to then slide out.

As for muffler "wool" the AMX stores sell it - I bought some from the Bayswater store, in sheet form and ready to cut and wrap.

timbo750 · « **Reply #664 on:** October 22, 2016, 10:30:44 PM »

Cliff, will have to try something, at the moment it is straight through the baffle so I expect it will too load for a road worthy. Should good though.

Did get some of the shelf fittings to sort the different vent tube sizes.

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timbo750 · « **Reply #665 on:** October 22, 2016, 10:39:14 PM »

Vent tube fitted.

timbo750 · « **Reply #666 on:** October 22, 2016, 10:41:55 PM »

Have another issue now. Was readjusting the rear brake and getting it right befoe the exhaust went on and whilst leaning on the brake pedal to make sure it return to the stop I bent the return spring. Are these springs normally weak/soft or have I got a fatigued spring.

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Terry in Australia · « **Reply #667 on:** October 23, 2016, 02:30:12 AM »

You've got a stuffed spring mate. Hey that pipework from the top of your oil tank isn't connected to the vent at the back of the engine is it?

If so, you misunderstood what I was saying Tim, that hose from the top of the oil tank just runs down the back and vents into the atmosphere, the small dia hose from the back of the engine should be connected to a similar sized pipe at the back of the oil tank. (at right angles to the two main oil hoses)

If still not sure, do a search for CB750 lubrication system, there are plenty of diagrams out there. Cheers, Terry.

timbo750 · « **Reply #668 on:** October 23, 2016, 02:35:18 AM »

Terry, clearly I misunderstood. I have an aftermarket tune up manual that may show that. I will also order a new spring.

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Terry in Australia · « **Reply #669 on:** October 23, 2016, 03:46:22 AM »

No worries mate, had you run it like that you would have pressurised your oil tank and you would have had the mother of all geysers of oil coming out of the oil filler, think of James Dean in "Giant" (if you're old enough to remember that movie) and it'd be close. Actually it wouldn't have been that bad, but I do like to dramatise where possible...........

timbo750 · « **Reply #670 on:** October 24, 2016, 02:56:59 PM »

Ordered a new spring for the brake pedal so have to wait before fitting the exhaust. Sorted the vent hoses thanks to Terry. Now that the electricals are sorted the head could finally close up the head light

timbo750 · « **Reply #671 on:** October 26, 2016, 02:47:57 AM »

Decided to fit the headers whilst waiting for the other parts to arrive. Although the exhaust I have looks to be made reasonably well, it doesn't leave enough room at 3 pipes to fit the standard clamps. When attempting to slip them past the frame 1 went past with no issue 2 have caused scrathes in the powder coat and 1 has no hope of getting past. I am hoping now to find an alternative clamp that won't look out of place.

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Terry in Australia · « **Reply #672 on:** October 26, 2016, 02:54:36 AM »

Hold the clamps over the exhaust ports (you might need an extra pair of hands) and just push the headers into 'em Tim. Cheers, Terry.

timbo750 · « **Reply #673 on:** October 26, 2016, 12:50:22 PM »

Thanks Terry. That might get one of my kids out of the house for 20 min. Also do you or have fitted oil pressure gauges to your bikes. If so do you know where to get one locally?

Terry in Australia · « **Reply #674 on:** October 26, 2016, 01:32:59 PM »

G'Day Tim, any 0-100 psi guage will work, don't use an air compressor guage as it's not designed for rapid pressure fluctuations and if not oil damped, the needle will just fly off. The more difficult issue is finding an adapter to mount it, so really, eBay is your best friend. Cheers, Terry.

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Author Topic: CB 750 Project 1 - Rides Well but a few tweaks needed (Read 115492 times)