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Hi all, noob with a 1979 CB750 Bobber, Can you source a new starter or only buy used?

lvin4jc

JoeBobber
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Hi there. My name is Joe. I just traded for my first motorcycle yesterday.

She's a 1979 CB750 Bobber Bike. A bit of a jalopy at the moment but we'll get that fixed in time.

Anyway, I have two questions mechanically, otherwise it runs great with the exception of dirty carbs or something (they get too much air so the PO blocked off most of the air filters with duct tape, it currently runs great with the duct tape... ... ... wouldn't be my first choice for a long term solution).

#1. I can only find used starters, can you buy new ones?

#2. There is a noise coming from the engine that isn't great. I'm a car guy, new to bikes so bear with me here. After doing research on how to replace the starter I saw the whole cam chain tensioner deal where it has to be installed at 15 degrees past tdc in cylinder 1 etc. etc. My current theory is that the former owner installed it without doing all that and the cam chain is making noise, that would describe this noise pretty well. However, it could be something completely different, I was wrong once before. Anyway, does that sound like a solid theory or do these have a know noise that is caused by something else? The engine seems to run fantastic otherwise with lots of power, easy start/warm up etc.

Thanks!
 
Welcome... I'm fairly new to the 750 so I will defer the technical answers to the experts...
 
Thanks Flogger.

In doing more research today I realized that my bike has pod air filters on it and that's why it needs tape over them to reduce the airflow way down. I like the look of the pods but maybe I need to get an airbox?

Enjoying learning more about this great machine!
 
Ah, pods... these 4 cylinder machines work best with the original airbox... but you will get a lot to counter that and I will prob take a beating... Pods only seem to work with custom pipes and with the carbs redone...new jets, ports, valve job, etc... I suspect most of the pod issues are caused by folks just slapping them on hence your duct tape! That is a first, lol... 4 carbs are expensive to have worked on and that becomes another issue. Folks work on them without really knowing what they are doing... I am having mine professionally done but that runs 100/150 a barrel plus parts... But I should never need that again. Usage, good usage, keeps them good vs sitting... plus treat the gas (the ethanol) with a couple ounces of seafoam each tank. Carbs hate ethanol...
 
Why would somebody WANT to get the rape of buying a new starter?

Pull clutch lever in at idle and see if noise changes.

To mess with cam tensioner engine must be out and opened up. Adjust tensioner and see if noise changes if the clutch lever thing does nothing. If lever moved changes noise then problems with clutch basket and internal dampers.

Common for tensioners to break at 30K+ miles if bike is in a hot climate. The rubber cracks and then delaminates off the spring steel tension blade. Chain noise generally gets worse at higher rpm................

Pods and less than optimum old motorcycles engines that don't seal as well as they did when new, a recipe for utter frustration.
 
Why would somebody WANT to get the rape of buying a new starter?

Pull clutch lever in at idle and see if noise changes.
It does not affect the noise

To mess with cam tensioner engine must be out and opened up. Adjust tensioner and see if noise changes if the clutch lever thing does nothing. If lever moved changes noise then problems with clutch basket and internal dampers.
Are you saying the engine has to be out of the bike to do this? I thought the tensioner could be easily removed with the engine installed. Also, are you saying I could just adjust the tensioner to put a little more tension on the chain incrementally and see if that makes the noise lessen? That would be great!

Common for tensioners to break at 30K+ miles if bike is in a hot climate. The rubber cracks and then delaminates off the spring steel tension blade. Chain noise generally gets worse at higher rpm................
Good guess, 32,000 :thumbsup:

Pods and less than optimum old motorcycles engines that don't seal as well as they did when new, a recipe for utter frustration.

tencharachters
 
3 tensioners in motor, one goes from front cam to back and part of it comes out with valve cover off. The other two are buried deep in motor and it comes out to get to them, head cannot come off engine in frame like SOHC. One is the main tensioner to cams and the other is a primary drive chain tensioner.

Yes to blue sentence #4.
 
Why would somebody WANT to get the rape of buying a new starter?

Pull clutch lever in at idle and see if noise changes.

To mess with cam tensioner engine must be out and opened up. Adjust tensioner and see if noise changes if the clutch lever thing does nothing. If lever moved changes noise then problems with clutch basket and internal dampers.

Common for tensioners to break at 30K+ miles if bike is in a hot climate. The rubber cracks and then delaminates off the spring steel tension blade. Chain noise generally gets worse at higher rpm................

Pods and less than optimum old motorcycles engines that don't seal as well as they did when new, a recipe for utter frustration.

What do you think of this method? - https://www.youtube.com/watch?v=Llm9yC1IBCI
 
Yes the chain adjustment shown there can work fine. Do NOT set them with engine idling like the service manual says, often they end up loose like that. Make SURE you ONLY turn alt rotor CLOCKWISE, if you reverse the chain adjusts looser.

Yes starter clutch spring issues in that vid.
 
Yes the chain adjustment shown there can work fine. Do NOT set them with engine idling like the service manual says, often they end up loose like that. Make SURE you ONLY turn alt rotor CLOCKWISE, if you reverse the chain adjusts looser.

Yes starter clutch spring issues in that vid. Starter motor itself is fine, clutch just not locking up to flip engine over.
 
Yes the chain adjustment shown there can work fine. Do NOT set them with engine idling like the service manual says, often they end up loose like that. Make SURE you ONLY turn alt rotor CLOCKWISE, if you reverse the chain adjusts looser.

Yes starter clutch spring issues in that vid. Starter motor itself is fine, clutch just not locking up to flip engine over.

Yeah, he didn't explain how a lock nut works very well in that video but I get it. Ok, that's great.

I'm going to change the oil and tighten the cam chain and see where that puts me. If the clutch still does that I'll order the rebuild kit.
 
Forgot to mention that the front chain adjuster above the oil filter is SUPER EASY to strip out, common on used bikes. It just needs to be snug, you can tighten it more but don't. Also, the main primary chain (3rd chain) has a hydraulic adjuster that tensions it automatically, you don't mess with it.
 
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