well hello

Posted: Mon May 21, 2012 6:34 pm

my name is richard mccrea. i just got my first cb750. its a 1981 dohc supersport. picked it up off of craigslist for $700. it runs relatively ok. doesnt want to idle and has a bit of cam-chain noise untill 2000rpm. other than that it runs just fine. valve cover off and yes its the cam-chain. cam-to-cam chain is ok but the cam-to-crank chain has play in it. 27000 original miles. my biggest problem is that the front cam-chain set srew/bolt and nut are missing and that it is stripped out. im in the prosses of drilling it out and getting a "time sert" installed. my question is are the set screws/bolt and lock nut still available through a honda dealer or anywhere else? ive done some serching and have come up dry! also if there is anything i should watch out for when drilling and installing the "time-sert"?? im a mechanic by trade- i work as a tech at a local ford dealership. but its the first time ive done any work on cb's and we all know how first times can go!! thanks for any feed back!

Posted: Mon May 21, 2012 6:46 pm

Hi Dick, welcome to here wave

Please read the New Member's Thread if you haven't, and fill in your sig as it says in there. There's a green link to it in my sig.

If you're a mechanic, and good with tools, TimeSerts are real easy. They come with all the right tools in the kit and instructions. Also they have videos at http://www.timesert.com/html/install.html#A on how to do it that are good.

The thing about the front tensioner set bolt hole in the head is that there is a void in the aluminum part way down, so it likes to make the hole go crooked if you're not ready for it. That void can also make the insert not want to stay in place after it's been expanded. I've JB Welded the inserts in before to make them secure, which works like a charm.

Here's another video from a third party:

http://www.youtube.com/watch?v=anjDQJtWFc8&feature=related

Posted: Mon May 21, 2012 6:50 pm

yeah ive done a bucnh before and havent had to many problems. should i take the adjuster out of the hole/ head before i start drilling and inserting the time-sert? i dont want to end up ruinning the adjuster rod!?

I fixed your signature HS

please read the welcome link on our homepage to learn forum basics

Posted: Mon May 21, 2012 7:13 pm

The front adjustment bolt and nut lock the tensioner for cam chain B. (Cam to cam). With it missing the rod should be extended fully toward the front and there shouldn't be any tension on the chain. Maybe the tensioner is seized. It should be looked into. The crank to cam chain is adjusted with the nuts at the back of the engine. You can dl the factory service manual (Check NMT) and look in the addendum for how to do it. As far as I know the bolt and nut are no longer available from Honda. You can probably get them used.

Posted: Mon May 21, 2012 7:49 pm

dick356 wrote:

yeah ive done a bucnh before and havent had to many problems. should i take the adjuster out of the hole/ head before i start drilling and inserting the time-sert? i dont want to end up ruinning the adjuster rod!?

what is HS?: "I fixed your signature HS"

Yeah, it wouldn't hurt to have that rod gone, unless you have what I call a bottoming drill and tap, which is a drill and tap with the tapered parts ground off to be able to get closer to the bottom of a blind hole or in this case the shaft of the tensioner. You could also get shorter inserts that would allow you to not have to get too close to the tensioner.

But really, there will be chips to remove too, and that's probably much easier without the tensioner in the way.

Oh, and yes, the bolts and locknuts with the bevel for the o-ring just went NLA from Honda a year or two ago. I don't know if you saw what they look like, here are some pics:

You'll have to find used ones. You can see that the bolt is stepped and has 8x1.25mm threads on the bottom part, then the smooth part where the o-ring seals, then the top for the lock nut has 10x1.25mm threads. All capped with a 10mm hex head. Kind of a Rube Goldberg thing really.

Posted: Mon May 21, 2012 9:09 pm

thanks a BUNCH- yeah i had no idea what the bolt looked like since mine was never there!! i guess ill have to find a "cap" for the end of the hole in the head as well since i dont have one either! you guys are awsome and i greatly appreciate the help/info!! ill keep you informed!

Posted: Mon May 21, 2012 10:18 pm

The caps are still available.

Posted: Mon May 21, 2012 10:30 pm

Quote:

what is HS?: "I fixed your signature HS"

Holysmokes ...

Posted: Tue May 22, 2012 6:34 am

Looks like Gene has all the caps! Very Happy

Posted: Tue May 22, 2012 12:56 pm

HS is short for me

not high speed

Posted: Tue May 22, 2012 1:35 pm

ok - im trying to get the slack out on my cam chain. the chain from the cam-to-crank. i cant run the bike right now because the valve cover is off. the manual on here says to only loosen the bottom rear nut but the manual i have says to loosen both rear nuts!? more importantly- how tight should the chain be at correct tension and how much more does it tighten up when you do the adjustment with it running. i just want to get it as close as posably before i fire it up again beacuse it was rubbing a grove in the head the way it was.

Posted: Tue May 22, 2012 4:10 pm

There's a sticky in tips and tricks about cam chains. You need to look around here. Most stuff is covered someplace.

http://www.cb750c.com/modules.php?name=Forums&file=viewtopic&p=231538#231538

Posted: Thu May 31, 2012 9:14 am

ok-got the hole time serted- now if you look down set screw hole the adjuster rod only goes halfway past the set screw hole. is this a problem? the chain is tight, am i just out of adjustment and will need a new adjuster in the future??? ive searched all over the site and in both manuals i have and theres no info on how far the adjuster bar/rod should or shouldnt be in the bore of the head.

Posted: Thu May 31, 2012 10:45 am

You might be at the far end of the adjustment, or something might be broken. I'd take the valve cover off and see if everything looks ok. You can take a pic and post it up if you like.

Posted: Thu May 31, 2012 11:29 am

How do you know the chain is tight ?

Posted: Thu May 31, 2012 12:08 pm

the valve cover is off-nothing is broken, and if i push down on the adjuster the rod does move out and then back in. the chain is tight, but im just alittle concered that there is about an 1/8 inch opening in the set srew bore after the rod ends.

Posted: Thu May 31, 2012 1:16 pm

Could be the chain is shot .

Can you lift the chain links away from the sprockets while the chain is tight , anywhere on the sprocket ?

Posted: Thu May 31, 2012 1:53 pm

no sir- the chain seems to be ok- no binding or looseness anywhere and i cannot lift it away from the sprocket. i havent had it off to measure it, but it has proper amount of tension on it. the bike runs fine, besides the chain noise i had coming from the a chain(cam to crank) and have adjusted that chain correctly now. how far should the adjuster rod "normally" be away from the front openning where the plug goes? and should i be ok running the bike the way it is now-with the proper amount of tension on the chain and the set screw/bolt now time serted in place??

Posted: Thu May 31, 2012 2:46 pm

ohh...and why does everyone hate the pods???

Posted: Thu May 31, 2012 3:10 pm

search pods

we don't hate them , they are just worthless on cv carbs

Posted: Thu May 31, 2012 3:27 pm

I'm not sure there is a 'normal' distance that rod should be away from the plug . It does seem odd that the rod is as far in as you describe .

Do you know how many miles are on the cam chains ?

How much of the A chain tensioner inner slide is above the outer slide ? 'A' chain being the crank to cam chain .

I ask this because both A & B ( cam to cam ) chains are recommended to be changed at the same time , so one could be used as an indicator for the other . Obviously , this is hardly a reliable way to judge chain condition , just a rough indicator .

Posted: Thu May 31, 2012 3:39 pm

pd750- the bike has 23000 miles on it- if i had to guess i would say that they are the original chains. they look ok, and now are adjusted properly. im not sure of the distance on the a tensioner is above the b, ill have to check tonight. im thinking i should be fine because the cains are adjusted properly so i dont see where the harm should be in running it like it is for now. ill just keep an eye on it. thanks for the help!! so why do these pods not work on stock carbs?....too much air/not enough air?? i dont see how a filter would change the bikes performance all that much. air and fuel is what they do. i can see how they would need to be re-jetted, but for them to be as bad as everyone is saying on here, i just dont see it!? any reason as to why-and not just they dont work, or work well would be appreciated. this is more of a question as to why they dont, not if they do.

Posted: Thu May 31, 2012 4:04 pm

Quote:

so why do these pods not work on stock carbs?..

Just a couple of threads on the topic :

http://www.cb750c.com/modules.php?name=Forums&file=search&mode=results

Posted: Thu May 31, 2012 7:01 pm

pd750 wrote:

Quote:

so why do these pods not work on stock carbs?..

Just a couple of threads on the topic :

http://www.cb750c.com/modules.php?name=Forums&file=search&mode=results

Pete, you can't send someone to a results post from a different session. It will just show the Search Query page. That's the very thing I'd like the search to be able to do, id either have a url command line type entry capability, or be able to post the results to a message. I've managed to get it to work for me as a protected user, but if I post it, the software complains that a normal user has performed an illegal function and threatens to lock them out.

Dick, with a new B cam chain and tensioner, the adjuster's rod end will be almost touching the plug in the front of the shaft. Yours is worn out. It probably has not had good maintenance and the chains were left loose and the oil dirty. This causes the chains to flail about wildly from the pulsing tension they under go, and pins to wear rapidly, making the chains get longer, and maybe undue wear on the tensioner. They will need changing before long.

Posted: Thu May 31, 2012 7:25 pm

Quote:

Pete, you can't send someone to a results post from a different session. It will just show the Search Query page. That's the very thing I'd like the search to be able to do, id either have a url command line type entry capability, or be able to post the results to a message. I've managed to get it to work for me as a protected user, but if I post it, the software complains that a normal user has performed an illegal function and threatens to lock them out.

Dang . Of course , you are right . I guess that'll teach me to check my links before posting . Sorry .

Dick ,

I tried to save you a couple steps but it didn't work the way I thought it should . Sorry .

Anyway . just type 'pods' in the search engine . You'll find enough info to answer your question .