Author Topic: 1974 CB750, new bike, new owner, new user, and new questions :P (Read 10400 times)

Jerry Rxman Griffin aka MuthaF'er · « **Reply #50 on:** May 20, 2018, 10:30:02 AM »

"housing is stuck"?? In the engine? If so, under the shifter side cover, jiggle the shift drum in and out.

piefairy · « **Reply #51 on:** May 20, 2018, 02:15:42 PM »

Well, I thought it was stuck until I finally saw a good image of the underside of the engine. Apparently there is a retaining bolt with a key'd washer that holds it in. (I was wondering how it would stay sealed without threads). Now I just cant figure out how to get that bolt loose. Its on top of the frame and I cant get a ratchet in there or a good grip with it with pliers. Any suggestions?

Also, I started wiring in my idiot lights today. The oil pressure light turns on as soon as I give power to the engine, I assume this is correct since the engine isn't running? Its a low pressure sensor and not a high pressure sensor correct?

Also, to whomever on this forum posted about using a syringe and backfeeding the brakes from the bleed nipple up, THANK YOU. Made life so much easier than trying it the traditional way with a bleeder pump.

piefairy · « **Reply #52 on:** May 21, 2018, 07:26:09 PM »

Is the bolt that holds the neutral sensor switch in a 6mm head? I've only found 1 vague reference to it, and I need to get a crescent wrench for it.

70CB750 · « **Reply #53 on:** May 22, 2018, 01:29:58 AM »

Quote from: piefairy on May 21, 2018, 07:26:09 PM

Is the bolt that holds the neutral sensor switch in a 6mm head? I've only found 1 vague reference to it, and I need to get a crescent wrench for it.

Pretty sure it is M6 - wrench size 10. Get a metric 1/4" socket/ratchet set. They are like $10 at Lowes.

piefairy · « **Reply #54 on:** May 22, 2018, 04:36:41 PM »

I have a ratchet set but I cant even get the 10 socket over it without hitting the frame, it will not seat fully on the bolt, only about half way at best. I am planning to try a crescent wrench next.

piefairy · « **Reply #55 on:** May 22, 2018, 06:17:25 PM »

Here is a one off question... are the 1975 cb750 corbin seats able to fit on the 74? The mircrofische seems to list all the same parts, but that doesn't mean the welds are in the same place.

Thanks

piefairy · « **Reply #56 on:** May 24, 2018, 04:17:31 PM »

Ok, I'm getting frustrated with this damn neutral switch. I got a crescent 10mm wrench on it and it just skips off when trying to unscrew it. I've tried getting a socket head on it, but it hits the frame even before I attach the socket wrench. I did cut down a 10mm socket head so it will fit over the bolt, but I still don't have room to put the wrench on it even with a right angle drive adapter. I hit it with a propane torch today to try and loosen it up, got it hot enough that the paint on the engine started to bubble and burn off (didn't want to get much hotter in case there were internals or seals that may melt). Still no luck. I cant think of anything else to try except pulling the engine to get it loose and I REALLY don't want to do that. I am about to just gut my new neutral sensor and put the insides into the old one and use liquid gasket to seal it back up, but that would still leave the oil drip coming from the old switch... Anyone have any ideas? I'm at a loss for what else to try. The bolt head is literally directly over the frame tube on the bottom of the bike with not much clearance, a 1/4 drive socket will not fit on without cutting it down.

But on the bright side, the wiring is done short of the speedo, its been a pain to find a motoscope mini in stock anywhere but finally have one coming. As long as I can at least plug the neutral hole, she should be running tomorrow or saturday at the latest. Just in time for the long weekend

piefairy · « **Reply #57 on:** May 25, 2018, 03:45:03 PM »

I ended up loosening all of the bolts holding the motor in place and jacked up the engine, still not enough room. Fortunately/unfortunately the bike decided it wanted to lay down... so while it was on its side I was able to get a better look at what I was dealing with. I raised the motor up as high as I could with a wood board. I still couldn't get a socket with a right angle drive on the bolt. I hit it with a torch again, then took a flat screwdriver and a hammer and hit the edge of the retaining plate that actually holds the switch in place. It finally broke free. Replaced the switch, re seated it, and picked the bike up to see if there was any damage. Luckily there doesn't seem to be. I have a lot of the parts off the bike, the only thing that looks like it took a hit was the points cover, which was already dented when I purchased the bike. I have 2 new condensers to put in there are well since one was dented.

Thanks for the help.

piefairy · « **Reply #58 on:** June 01, 2018, 12:01:30 PM »

CalJ, was riding the bike a bit today and noticed the horn would blip a little bit at higher rpms, 5500 ish. Is that a low battery alert? I know the battery is undersized for the bike. The shop reccomend what I think is a 6 cell lipo and I've since heard I should have at least an 8 or 12 to make up for the poor efenciency of the older field coils.

piefairy · « **Reply #59 on:** June 01, 2018, 06:07:43 PM »

I have a moto mini, but I have yet to figure out how to get them to "talk" to each other... if they are supposed to.

I have Ricks rec/reg on the bike, and I can see it charging the battery via the m-ride app, but after startup, the bike will drop from 13.4v to about 11 to 10.5. Ignition upon connecting to the phone is pulling 1-1.5 amps even before starting the bike. It seems to stay balanced at around 2500 rpm, it will "charge" at about 3000 to 3500, and seems to drain above that.

Cant really play with it for a bit, the carbs are being synced/rebuilt at the moment, but I am trying to prep for when its back.

piefairy · « **Reply #60 on:** June 01, 2018, 07:51:04 PM »

Also, this is the battery I have installed.
https://shoraipower.com/products?action=vehicle&type=175&make=380711&model=380755&year=380755

Is it a bit underpowered?

piefairy · « **Reply #61 on:** June 02, 2018, 01:41:14 PM »

There are only 4 wires connected to the neg terminal on the battery, one is the negative to stock frame ground, one is for the recharge plug/battery tender, and the third is to a USB charger that is on board, last is the black ref wire from R/R if I remember correctly. The M-unit is getting its ground from the accessory tray I mounted it to, the NEG to the battery terminal is one of the bolts to mount the tray. Paint has been sanded off at this and all contact points. The POS for the USB is wired to AUX 2. Sorry, I also misspoke when I said voltage would drop PRIOR to ignition. It is immediately after ignition that the voltage level drops to between 11 and 10.5. It will get back up to around 12V in about 10 seconds of idle, but again, my bike is idling high.

I am running a 10W headlamp with integrated turn signals
https://www.dimecitycycles.com/bikemaster-led-headlight-with-integrated-turn-signals-7-amber.html

The only other lights I have on the bike are a set of rear LED brake/turn signals and a pair of bar end lights. Neither of these should pull much. One thought I had is that everything I am running is run in parallel, but the bike should have enough amps in it to compensate. All the lighting is grounded at its installation point, but I have checked the ground point resistance to the battery NEG and it reads at 0ohms at all point, but that does not ensure how "clean" the flow is.

Did that battery look like it has enough power? I know its the same/similar to one I saw in your builds, but its a different size engine. Another note is that to get the bike above 3500 rpm takes some work since its running so rich and there is a power dropoff right at the start of what should be the power band of the bike. 5500 to 6k RPM is the most the bike will put out and if I throttle further the RPMs stay the same but the cylinders start to sound rough and backfire increases.

I did not have my phone accessible while I was riding to really monitor the voltage, all of my charging/discharging observations are done from neutral.

piefairy · « **Reply #62 on:** June 02, 2018, 04:32:40 PM »

I'm sure I am mistaken then. I will check it again as soon as I can. Its in a friends shop at the moment to get the carbs balanced.

piefairy · « **Reply #63 on:** June 02, 2018, 05:04:57 PM »

I will. I do imagine that I do not have that wire connected to NEG. I connected it to AUX2. I remember the conversation you had and that I have both AUX2 ports filled. I know my LOCK has no connection unless I am bypassing the bluetooth connection. I noticed that even if the phone dies or looses connection the LOCK will not trip unless the bike is shut off.

I am wondering though if I bought the standard or the lithium version of RR... The only order I don't have an itemized receipt on is the battery and the regulator...

Also, Calj I forgot to ask. I wired the tach pickup on the moto mini to the negative of one of the two I guess would be ignition coils? The two large capacitor looking items under the tank. Does this give an accurate tach reading on a 4 cyl since the coil supports 2 cylinders or should I cut the value in half? 2k rpm would be 1k? I'm not sure if 1 rotation is done by 2 cylinders per cycle or not.

piefairy · « **Reply #64 on:** June 04, 2018, 02:15:17 PM »

Calj,

Just got the reply from the company I bought the reg/rec from and it seems I did indeed buy the standard rec/reg, not the lipo. Could this be the problem with the charging while riding? I know it is bad for the battery, but hopefully since I only have about 20 to 30 miles on it, the battery will be ok after replacing the rec/reg.

piefairy · « **Reply #65 on:** June 04, 2018, 02:26:41 PM »

Ok, so the 10-100 Ricks Reg is correct then. Thanks, just wanted to make sure. I'm trying to think of the possible issues before I get it back so I can have parts on hand if needed.

piefairy · « **Reply #66 on:** June 04, 2018, 05:04:16 PM »

Thats the unit I saw and thought I made a mistake. The site I bought off of, as well as RR's site, says nothing about lithium.

piefairy · « **Reply #67 on:** June 05, 2018, 02:31:01 PM »

Another question for you. With the Moto-Mini gauge and the speedo pickup. I know the M-unit is looking for the speedo input from the pickup, as is the moto-mini, but I cant find anywhere that the M unit will "talk" to the moto-mini, so I am assuming that I am just suppose to wire the speedo output to both units and calibrate them individually?

Thanks

piefairy · « **Reply #68 on:** June 05, 2018, 07:17:22 PM »

Thats what I thought after going over it. Thanks for the confirmation. You would think they would have some level of data-link, but maybe thats for the M-unit 3.

piefairy · « **Reply #69 on:** June 06, 2018, 04:32:59 PM »

It was more of a thought about the units synchronizing together for speed, tach, time, trip, and measurement unit. I get that this would render the moto mini just a "dummy" display as all the actual processing could be done by the M-unit, but just was hoping the "custom parts" option in the app would offer more for the motogadget accessories.

piefairy · « **Reply #70 on:** June 07, 2018, 07:00:39 PM »

I'm not conflating, just hoping/wishing/dreaming

piefairy · « **Reply #71 on:** June 08, 2018, 05:00:14 PM »

Quote from: calj737 on June 07, 2018, 07:54:19 PM

Quote from: piefairy on June 07, 2018, 07:00:39 PM
I'm not conflating, just hoping/wishing/dreaming
Then please dream for something useful.

Ill dream of a genie, or a broken down Budweiser truck in front of both of our houses then.

Any thoughts on the tach pickup? I am curious on that, I'm not sure how the cylinders cycle. I believe its 2 cylinders, 1 cycle/rotation, which would equal the RPM but just want to make sure.

piefairy · « **Reply #72 on:** June 08, 2018, 05:34:05 PM »

Quote from: calj737 on June 08, 2018, 05:12:42 PM

Quote from: piefairy on June 08, 2018, 05:00:14 PM
Ill dream of a ...broken down Budweiser truck in front of both of our houses then.
You keep that panther piss, I’ll stick with Goslings Black Seal, thank you very much

How about a nice bottle of glenmorangie? I owe you something after all of this

piefairy · « **Reply #73 on:** June 21, 2018, 03:08:28 PM »

Ok, been a bit since I posted on here. Got the bike back today. There is definitely a charging issue. My mechanic was running into the same problems. Check the voltage at the battery when running at around 7k, we were getting 12.04. The wiring of ricks rec/reg are as follows,

All yellows are connected to yellows from the stator
White is connected to White at the stator
Green is connected to green at stator (not green w/ red stripe)
Red is connected to POS at battery
Black is wired to AUX2 on the M-unit
The other green is wired to ground

I went ahead and metered the wires to the stator and yellow to yellow run between 0.7 to 1.2 ohm, which I know is to high. Also white to green, when disconnected from the rec/reg, are reading 10 ohms.

Any thoughts?

Bike runs really nice now though, as long as it has a fully charged battery

piefairy · « **Reply #74 on:** June 21, 2018, 05:10:03 PM »

They are roughly the same 12.04 to 12.03

Also, just as a refresher, it will maintain a charge at 4k or less, but at about 6k rpm it drains, which is why I am suspecting something with the stator or rotor

My multi-meter has been a bit jumpy lately, i will be picking up a new one tomorrow.

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Author Topic: 1974 CB750, new bike, new owner, new user, and new questions :P (Read 10400 times)