Search results

Makes sense, Although should turning on high beams activate the rear running light? Currently it doesn't so I went back to the PO did for now. Although I would like to have this fixed properly. I also seem to have a strange issue of my guage lights activating and blinking with my signal lights...

Problem solved with the headlight

ahh no idea that was the case Thanks!

Deleted problem solved

Hey Everyone, I swapped out my wiring harness today for a new one from vintagecb750.com While doing this I noticed that there was an additional wire running from the rear brown connector all the way up to the headlight and plugged into the black that would normally power the signal buzzer (its...

Accel pump 100% works on all 4. I am able to squirt fuel right out the front of the carbs when I have it out of the bike. I have heard people have some luck with the older carbs without the Accel pump. If they raise the needle. Would that actually help or just cause other issues if I shimmed...

Ah my bad #35. Finally received new coils and now all 4 cylinders are working. So far this is the happiest i've seen the bike I had to adjust my mixture screws with the additional cylinder burning gas every stroke instead of every few. I was able to get reasonable throttle response out...

Ahh shoot my bad went back to size 35. Anyways went back to the 40. I cut the ends of the wire and recrimped, still had the same issue. so I swapped the ignition coils. And then the same issue appeared on 1 or 4 with the 1/4 spark plug wires attached. depending on which wire was attached. so...

Found something interesting today. I switched the ignition cables between #2 and #3 and now #3 is the one not firing correctly. these are brand new coils and cables. does it make sense something is up with the cable as the coil still fires one of them fine? There is spark from both. I will...

Is there a possibility of a bad pilot jet? I'm using #40 I purchased off cb750supply. I've probably cleaned these 12 times trying to figure out what's going on. I have them on my bench right now and air blows through all jets easily

Yes it will respond, Nothing wrong with the colortune it just made the issue more obvious I'm using Magna dual output coils with whatever wire they come with Dynatek ignition NGKD8EA plugs and boots The color tune works great on all other cylinders it just made it very obvious to me that #2...

Sorry, wrote things down wrong everything is around 135 psi +/-5 psi Even if I did have a pump that wasn't accurate if there was a compression issue on just #2 wouldn't it be getting a much different reading than the other 3?

Yes all cylinders were within 5 psi of spec

Yeah Ideally I would like to get to that point, But I need to figure out why cyl #2 isnt igniting consistently below 2000RPM first. I realized I've checked all valve spacing apart from #2 intake as I cant get it with a socket and a the crescent wrench seemed like it wanted to strip it. (17mm...

I'm still learning tons so by no means am I even close to an expert so I may have done a few things wrong. Originally the bike was barely running and had to idle at 2500 RPM. So every time I've tried a new potential fix for its many symptoms its seemed to get better and better. I believe I saw...

I will give it a try today with carb cleaner. brand new ignition system and coils so I'm assuming the spark is good (you can also easily see the spark through the colortune as it performed perfectly on the other cylinders especially #3 with the shared coil. Thanks THomas

Hey Everyone, Noticed a bit of an issue today. I was using a colortune system to adjust my mixture and I noticed that cylinder 2 was firing intermittently below 2000 RPM. You are able to see the spark but there is only ignition every few cycles. There wasn't any obvious signs of a vacuum leak...

Hey guys, Trying to get the bike tuned a little better, Right now from at Idle when I give a large throttle blip there is little response/ the bike almost dies. I cant be a bit more gradual and its ok. Same for once I'm at a bit higher RPM. Fuel accel pump is working. Currently only non...

Hey Everyone, I've Been working on my CB750 for a few months now and have found a pretty decent amount of help on the forums. Before the bike was barely running and wouldn't idle below 2000 rpm, Now its quite better but still a ways away from running well. I'm not a mechanic so don't be...

Just took the bike for a spin around my parking garage, didn't adjust the mixture screws yet Am I right in thinking I should be able to roll around on flat ground at idle with using only the clutch and no throttle? I have to rev up to around 3000 rpm to get moving. and then I can start to bring...

Ok awesome. I was going to try and see if i can get it a little better with the mixture screws. I reset them back to factory spec. But I found an extra half turn helped when the problems were worse. I've essentially taken them apart 4 times now. The 1st time was almost a complete rebuild they...

Ok, Checked over everything again, I found the valve that fills the accel pump was clogged so it would slowly refill. so now the pump spits out wayy more gas. Throttle still doesn't really want to work until around 2100 now but its getting better. I will check compression and sync them next so...

Thanks, Could you point me in the right direction of checking the fast idle? Can't find any info online about it. Maybe I'm searching the wrong thing

Just checked on #3 it was full of gas when I opened the bowl. The drain valve was just completely clogged

OK so I found the problem, The float needle was sticking, I should have specified that It was the main carb needle that I didn't replace not the float needle. I replaced the needles in 3 and 4 with the old float needles and they seemed to function correctly when the bowls were off and I was...

I was doing the same thing with the carb cleaner as well when I rebuilt them. Im using the stock 4 to 4 exhaust. Just checked the floats with the clear tube method. Carb 4 was absolutely empty 1 and 2 were perfect 3 seemed empty as well strange considering I wasn't having an issue. Could 3...

I was able to blow spray carb cleaner and compressed air through everything. I didn't notice any clogs in the idle circuit or anywhere else. I had all cylinder firing before I rebuilt the carbs so I will check the floats first.

Yes pump was squirting and I replaced the Idle jets with new ones I will try the clear tube test although I manually set the floats with a calliper when I had them apart. I don't think it is the battery I just tried starting the bike and it was impossible with the electronic starter and with the...

OK so new developments. When I came down to the bike this morning I noticed that the carbs drains had leaked a decent chunk of gas over the floor- No signs of gas on the gearbox so its all coming out of the drain. Does anyone know what would cause this? Also the bottom of my airbox was wet with...

The bike was running before but also had problems getting an idle RPM under 2500. I made sure to give the idle circuit a blast with carb cleaner and air when I took them apart. and I soaked everything in pinesol for a few hours as well. Before I could get the bike down to 1500 RPM but it would...