Topic: Trying to do the cb750 tuneup. Are there any clear and easy step by step guides?

[ChopSticks]

I have the downloadable service manual and currently going through the tune up section which refers back to the main manual for certain parts. It doesn't really mention any tools that would be required though such as feeler gages for the valve tappet clearance.

Also it really doesn't outline specifically what to do for the less mechanically knowledge folks, was wondering if anyone had links to easier / clearer guides, videos would also help, as I've tried to search youtube to no avail.

My main weak spots are

Check and adjust ignition system
Adjust valve tappet clearance
Adjust cam chain
Check and adjust clutch

What tools / parts would I need in addition to  your regular tools (wrenches, sockets, drivers etc) like feeler gages, and rubber gaskets for tappets? where can I get the gaskets from? etc

And how important is it to clean the oil pump strainer?
I didn't do that part when I did the oil change because it said unscrew ten bolts, (6mm) which at the time I couldn't find where in the hell the 10 - 6mm bolts were. (and would I have needed to change the gasket for the oil pan if I did do this step?)

Lastly, after doing the oil change, I was curious what parts there were and was referring to the parts list for the oil filter. I don't ever recall encountering the seat, oil filter spring washer 15414-300-000, how important is it to have this? not to mention, it seems like I may have had an extra cylinder part that went around the bolt comp 15420-300-020 which was the same length as the spring

[evanphi]

Buy yourself a timing light to check the timing. That makes things easier! Clip to battery, clip to #3 or #4 plug wire (depending on which points set you are adjusting), start bike, flash light, adjust if needed.

Get a set of feelers, this will be used for the tappet adjustments as well as setting points gap. Adjusting tappets for the first time takes patience!!!

cam chain:

Clutch adjustment is pretty well laid out in the book. You should just need a small adjustable wrench, and flat blade screwdriver.


Check the FAQ. Plenty of good guides.

[70CB750]

Are you suspectng there is some gunk stucked on the oil pump screen?

People pull the oil pan to take a look before getting new-to-them bike on the  road, in another words cleaning the screen is not part of regular maintenance.

[70CB750]

Tappets holes have only o-rings on them, most of the time these are reusable.

30mm o-ring btw.

If you dont know CMSNL yet, check it out:

http://www.cmsnl.com/honda-cb750-four-k3-usa_model481/partslist/E++01.html#results

Very helpful for the exploded views.

[ChopSticks]

Buy yourself a timing light to check the timing. That makes things easier! Clip to battery, clip to #3 or #4 plug wire (depending on which points set you are adjusting), start bike, flash light, adjust if needed.

Get a set of feelers, this will be used for the tappet adjustments as well as setting points gap. Adjusting tappets for the first time takes patience!!!

Check the FAQ. Plenty of good guides.

Wait why would I need a timing light? what part of the ignition does that test? Sorry first time hearing about this whole timing light thing

also would this be good?
http://www.amazon.com/INNOVA-3551-Inductive-Timing-Light/dp/B000EVYH72/ref=sr_1_1?ie=UTF8&qid=1434481704&sr=8-1&keywords=timing+light&refinements=p_85%3A2470955011


And would this be sufficient for feeler gauges?

http://www.amazon.com/25025-26-Blade-Master-Feeler-Gauge/dp/B000BYGIR4/ref=sr_1_1?ie=UTF8&qid=1434481479&sr=8-1&keywords=feelers

[ChopSticks]

Are you suspectng there is some gunk stucked on the oil pump screen?

People pull the oil pan to take a look before getting new-to-them bike on the  road, in another words cleaning the screen is not part of regular maintenance.

Not sure, I just got the bike at the beginning of the year, and it's had an unknown amount of owners. The bike was not in running condition when I first got it. and from everything I've read on this site it's recommended to do a full tune up before anything else? which the oil screen thing was part of the tuneup, or have a mistaken what kind of tune up I should actually be doing? (fyi it runs and idles now, just has problems when getting out of 1st)

[ChopSticks]

Tappets holes have only o-rings on them, most of the time these are reusable.

30mm o-ring btw.

If you dont know CMSNL yet, check it out:

http://www.cmsnl.com/honda-cb750-four-k3-usa_model481/partslist/E++01.html#results

Very helpful for the exploded views.

Ah thanks, are they any special type of o-rings? like do I need nitrile or anything? or can I just get them from napa? since CMSNL isn't US based

[70CB750]

I see.

By all means, pull the oil pan.  You can get  a new strainer for the oil pan if you wish from this guy:

http://forums.sohc4.net/index.php/topic,145425.0.html

Clean the screen without taking it out unless you want to replace it - the rubber ring can crack since it is old.

There is a procedure called 3000 miles tune up, should be in the manual you can download here.  That is the base, to make sure bike is ready for season or before any other troubleshooting.

[70CB750]

Tappets holes have only o-rings on them, most of the time these are reusable.

30mm o-ring btw.

If you dont know CMSNL yet, check it out:

http://www.cmsnl.com/honda-cb750-four-k3-usa_model481/partslist/E++01.html#results

Very helpful for the exploded views.

Ah thanks, are they any special type of o-rings? like do I need nitrile or anything? or can I just get them from napa? since CMSNL isn't US based

Personally, that is something I would get on ebay:

http://www.ebay.com/itm/honda-cb750-cb550-cb500-cb400f-cb350-cb350f-TAPPET-BOLT-COVER-ORING-o-ring-seals-/291288548407?hash=item43d2268437&vxp=mtr

but there are other places.  Your local Honda dealer likely has them too.  NAPA could be more expensive, also it should be metric.  Some local HW stores have metric o-rings too.

[70CB750]

A trick that took me some time to learn is to use Honda part number, like 91302001020  for this o-ring and paste it in google:

https://www.google.com/?gws_rd=ssl#q=91302001020+

It gives you all the online sources.

[ChopSticks]

I see.

By all means, pull the oil pan.  You can get  a new strainer for the oil pan if you wish from this guy:

http://forums.sohc4.net/index.php/topic,145425.0.html

Clean the screen without taking it out unless you want to replace it - the rubber ring can crack since it is old.

There is a procedure called 3000 miles tune up, should be in the manual you can download here.  That is the base, to make sure bike is ready for season or before any other troubleshooting.

Nice, thanks! But what if I already did the oil change and everything is the strainer something I can leave off until the next oil change?

Also I am using the manual downloaded here.

So far I've changed the oil / oil filter, upgraded from paper air filter to K&N, bought a new AGM battery, and since I've finally gotten the bike to run I'm going to be switching the spark plugs and doing a compression test this weekend. Just wanted to lump a few more of the tune up items while I got the bike apart and everything

[flybox1]

you really want to be running that bike if your oil pump screen looks like this? 
http://forums.sohc4.net/index.php/topic,54893.0.html

Drain your oil pan, remove it, and clean the screen!   
If its not dirty, you're in luck!!!  If it is, only time will tell if you have more work to do.

[70CB750]

Leave it to the next oil change.

The best thing you can do now is to ride it, I would even wait with the compression test,  give the bike some time to heat up and cool down and loosen up rings and burn carbon in cylinders.

My K0 was so so on compression, when I was just riding it up and down the road getting it ready for inspection and tags - after few weeks of riding it, compression improved a lot. 

[madmtnmotors]

Nice, thanks! But what if I already did the oil change and everything is the strainer something I can leave off until the next oil change?

You can, but only if two conditions are met:

>Does the oil light work? (Does it come on when you turn the ignition on and go off after the bike starts?)
>Does the oil light stay off when riding?

As long as these conditions are met you should be fine. I had one that would only get two miles before the oil light came on. This is what I found when I dropped the oil pan:








 

Holy crap!

I mean HOLEY COW!



After cleaning the screen and replacing the o-rings, I put the pump back in and ran the crap out of it. Never had any oil feed related problems after that. 


From that point on I now make it a point to drop the oil pan on every SOHC CB750 that I touch. 

[70CB750]

Haha, your call 

What Flybox is showing is bit of an extreme but he surely has a point.

[70CB750]

Wilbur, did you find in the Mexican Bay or something? 

[flybox1]

Haha, your call 

What Flybox is showing is bit of an extreme but he surely has a point.

Peace of mind, Prokop 
Id rather spend 30 minutes checking/cleaning an oil screen than weeks or more and many $$$ doing a top end rebuild because of oil starvation 
...and he can reuse his oil 

[madmtnmotors]

Wilbur, did you find in the Mexican Bay or something? 

LOL!

Not far from it... it came from the Gulf coast of Florida, although I think the open crankcase vents had more to do with it than anything else.

[ChopSticks]

A trick that took me some time to learn is to use Honda part number, like 91302001020  for this o-ring and paste it in google:

https://www.google.com/?gws_rd=ssl#q=91302001020+

It gives you all the online sources.

 

Yeah but only downside I've seen from this is they usually only gives results of sites that charge shipping per order costs so just to order a $3 o ring might cost $7.99 in shipping where Napa or some local parts store I can just pick them up for free

[ChopSticks]

Leave it to the next oil change.

The best thing you can do now is to ride it, I would even wait with the compression test,  give the bike some time to heat up and cool down and loosen up rings and burn carbon in cylinders.

My K0 was so so on compression, when I was just riding it up and down the road getting it ready for inspection and tags - after few weeks of riding it, compression improved a lot.

That's the thing how much of the tune-up do I really need to do if the bike starts up right away and idles right under 1000?

The only problem I'm experience currently is when I put it into 1st and try to ride it shuts down. Which I'm thinking it might just be a clutch adjustment at the moment?

[ChopSticks]

Nice, thanks! But what if I already did the oil change and everything is the strainer something I can leave off until the next oil change?

You can, but only if two conditions are met:

>Does the oil light work? (Does it come on when you turn the ignition on and go off after the bike starts?)
>Does the oil light stay off when riding?

As long as these conditions are met you should be fine. I had one that would only get two miles before the oil light came on. This is what I found when I dropped the oil pan:

After cleaning the screen and replacing the o-rings, I put the pump back in and ran the crap out of it. Never had any oil feed related problems after that. 


From that point on I now make it a point to drop the oil pan on every SOHC CB750 that I touch. 

Ugh... don't get me wrong I would love to do everything perfect at the beginning but just the lag of waiting for parts like o-rings etc is making me impatient to have to redo the whole oil change again.


>Does the oil light work? (Does it come on when you turn the ignition on and go off after the bike starts?)
>Does the oil light stay off when riding?

As for this, yes it appears the oil light does work. It turns on when I turn the ignition and turns off once the bike is started.  I actually gonna ask since the manual recommends oil pressure test after the oil change could I do that with a compression reader or do I have to buy a fancy oil pressure tester also?

As for the second question, I have no idea about the oil light when riding since I can't get it out of first at the moment  it idles beautifully though

[flybox1]

Expect 1000rpm if everything is stock, and correct, and its PERFECTLY tuned.
Between 1200-1400 is acceptable.

[flybox1]

if the clutch is stock, and you havent opened it up, you might have a bunch of delaminated corks in there.
put it on the side stand (oil drains away from clutch) and check the basket and plates.
I bet they are stuck to each other or the cork is coming off. 

[ChopSticks]

if the clutch is stock, and you havent opened it up, you might have a bunch of delaminated corks in there.
put it on the side stand (oil drains away from clutch) and check the basket and plates.
I bet they are stuck to each other or the cork is coming off.

Would you happen to have a guide? or video? or is this in the manual? because this is what I got



Actually I don't even know some of those words.. delaminated corks?

[flybox1]

HAHAHA....yeah, ok.   google images is a wonderful thing    so is your service manual 
"cb750 cork clutch plates"