How to diagnose and repair an old motorcycle PT2 with a Honda CB750. I take you through the full diagnosis process in part 1 so now we get started on the repairs by removing the bad ignition components as well as the carbs for rebuild.
I use my ultrasonic cleaner and soda blaster to get the carbs back to new before reassembly and take care of other odds and ends throughout the bike as I go. Once running I sync the carbs, bleed the front brakes, and go for a quick spin only to find that there is another ignition issue yet to diag. Through more testing it is found that I had a major voltage drop through the kill switch which had very dirty contacts upon disassembly. A bit of cleaning and we are all set!
Part1 – https://youtu.be/R6qqrQRkJyI
4into1 website:
https://4into1.com/
– Coil set used: https://4into1.com/ignition-coils-and-caps-honda-cb750-sohc/
– Air filter: https://4into1.com/stock-air-filter-honda-cb750-1969-1978/
– Float bowl gaskets: https://4into1.com/float-bowl-gasket-4-pack-16129-268-004-honda-cb750k-cb750f-1969-1976/
– Petcock rebuild: https://4into1.com/petcock-rebuild-kit-honda-cb160-72-77-350f-500k-550k-750k/
– Rear fuel tank rubber: https://4into1.com/genuine-honda-gas-tank-rear-rubber-holder-17613-292-000-cb450-cl450-cb750k/
Ultrasonic cleaner settings:
– I use a 30l unit like this one. Buy the biggest you can as it will quickly pay for itself. You will use it far more than you think! (amazon affiliate link where I get a small commission if you purchase)
https://amzn.to/31Jc1Ut
– I run mine normally around 50c for non painted parts and 35-40c for painted stuff
– I have been using mean green cleaner found at many stores as it doesn’t darken aluminum or oxidize. For my 30l tank I use a half gallon at a time along with a few lines of Dawn dish soap.
https://amzn.to/3ELYEkz
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#brickhousebuilds #cb750 #willitrun
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Another great video! Guess I'll be looking for a CB750 this summer. Maybe be able to find one at Vintage Days….
Another fine repair!
Really enjoy your vids. Glad I found them.
Love those old 750 fours, so fun to fix and ride. Nice survivor bike and you did an excellent job with all the repairs. Learned some good diagnostic procedures that are going to help me be better at troubleshooting issues. Haven’t ridden a cycle in a while, maybe get me one and ride this upcoming season. Really enjoy how thoroughly you inspect, clean and repair all systems on these bikes – you can repair mine anytime.
Enjoyed the video and RIDE SAFE!
I could sure use a tutorial on electrical systems related to ignition – the components and the what’s, whys, and wherefores represented by them individually, and as a group. You make it seem easy but for me I get kinda lost in it all. If you have any “wiring for dummies” reading recommendations I’d sure like to know about them. Your videos are really well done by the way.
Beautiful survivor that now runs great. Break down of the front brake was interesting for sure. I’ve been itching to get a bike, but my better half has other thoughts. Looking forward to watching another one of your entertaining videos. Be safe out there!
In 1971 I had some money for a motorcycle. Went to a dealership and found bikes in my 1300 dollar price range. There was a 500 Triumph scrambler and a Honda 750 on the showroom floor. In a fit of utter stupidity, I road off on the Triumph.
17:15!!
Where can I get my hands on a set of these or can you teach me how to make them?
I had a 72/ 750 back in the late 70's and at cursing speed it would go up and down on the rpms just a little. After cleaning carbs and no change I took it to Honda mechanic –it was the rubber tubes inbetween carbs and head that had small cracks in them. Just to let you know if you don't already.
And on top this customer got a Video of his bike for free
MUCH RESPECT ,YOUNG MAN ! LOVE IS- A 750/4 !
Top notch bike tech Jed. Good on ya m8 !
Just found your channel and subscribed. Excellent video on the diagnosis. Just went through a similar voyage with my '75 CB400F that I bought out of Minnesota. Man that is a beautiful Honda 750! Haven't seen episode 1 yet, but hard to believe that tank is clean enough inside to run, but apparently so. Looking forward to more videos like this. Now time to check your library for past episodes!
Nice video. When did Honda switch to CDIs? I had an old Suzuki and already come with a CDI…
this is amazing … I'm having some similar issues on my 1978 cb400a and have some questions if there is any way you could help me out that would be awesome!