front cam chain guide removal

anysnail

XS650 Addict
Messages
167
Reaction score
0
Points
16
just like it says. i got the top of the engine off and i absolutely have to change the front cam chain guide. it has HUGE divots drilled into it from the PO just letting the cam chain slap around like some kind of medieval mace.

my problem is i want to take it out without having to break the cam chain or take off the jugs. i was thinking maybe some alligator clips stuck to the end of a wire coat hanger. how did you guys do it?
 
To remove the chain from the camshaft:
-loosen the chain tensioner on the back of the engine...just remove the entire tensioner.
-Slide the bearings off of each side of the camshaft.
-You can now remove the camshaft without breaking the chain.

Remove the head and you can get to the front guide easily. I think I used this to grab it, can't remember.
http://www.amazon.com/OEM-25291-Fou...=2025&creative=165953&creativeASIN=B000CMFK0Q

If you want to remove the tensioner on the rear of the motor, remove the head, get the guide unbolted, use a grinder to grind the head off of one of the rivets, then you can pivot the guide apart and remove it from the chain(the chain passes through it). The rivet doesn't really do anything(the bolts will hold it in place), but if you're careful you can snap the guide back together later.
 
hmm, sounds more involved than i really wanted. is that the easiest way? my chain is in really great shape and so is everything else i can see. i just need to remove/replace the front guide.
 
The easiest way is as Pyro said. Pull the rocker box, and tensioner, slide the bearings off the cam, wiggle the cam out from under the chain, remove the head. reassemble with new gaskets guide. While you have the head off replcing the valve seals and lapping the valves is a good idea.
 
good God. i don't wanna wiggle anything off of anywhere and i REALLY don't want to mess with my cam. i fear that if i mess with the cam i'll never get the engine to run again. i just want to replace the front guide.

i have almost no experience with engines and this is the first time i've ever gotten this far into the motor on anything.

i could give a big long list of tools i don't have and can't afford but then you would just tell me to sell my bike and get something with a warranty!
 
Last edited:
Well, you'll need a torque wrench to put the head nuts back on at least.

You'll have to at least move the camshaft out of the way. Then you might can reach down in the tunnel with the parts pickup tool I linked to above and grab the front guide. The back guide definitely requires the head to be removed.

Here's how to line up the camshaft again.
http://www.650motorcycles.com/CamTiming.html
 
the back guide is in fine shape. i guess i'm just nervous to go that far into my bike's engine for fear of never getting it running again. it's not like i owe any money on it and if it doesn't run i could take it apart again.

>sigh<

if you two are saying this is the best way then maybe i have no other choice. :shrug:
 
Not replacing the cam chain is foolish if you have about 20K or so on the motor. Most originals are shot by then. I think you need some local help here. You're in there but you don't have a clue what you're doing, lol. You need to buddy up with a local 650 rider, someone who's been into one of these motors. Is it a simple motor? Yes - but not for someone who's never been inside any motor at all, ever. There are little tricks and "Gotchas" all over the place.

I don't understand the reluctance of many to pull the jugs off just to save the cost of a new base gasket. You really can't be sure of doing a proper top end job unless you do. Mounting and centering that front cam chain guide is half guess work unless the cylinders are off and you can see (and measure) how the bottom of the guide sits. New rings are usually needed and a thorough cleaning of the pistons, especially the ring grooves, as well. I don't know - I give up. Half-assed rebuilds are just that. When you have to tear it down again next year, don't say I didn't tell you so - because I told you so, lol.

This list is a wealth of info. I and others will walk you through a proper and thorough rebuild if you are so inclined. If you just want to slap it back together then, like I said, I told you so - it won't last long.
 
top end disassembly on this bike isn't bad at all - i was pleasantly surprised when i pulled apart my engine.

the 1982 honda CB750 i rebuilt a couple years back was a pain in the ass being a DOHC 4 cylinder.

just get a good manual, read over the process a few times before you even crack a nut, take your time with it and take plenty of pictures.
 
some tough love there 5twins. the last thing i want to is a half ass job but at the same time i don't have the passion for motorcycles that most of you guys do. i understand that the bike is 30 years old and work is going to need to be done but i am questioning whether or not i even want to do it. too many tools i don't have and too little time add up to a big question mark.
 
You know you can get the top off and back on without a problem, or you wouldn't have taken it off. The rest is no big deal either. Just stuff you hadn't planned on maybe.

5twins - you say a motor with 20k typically has a shot chain if it's original. What's the best compression an original motor with 20k would have have? Trying to sleuth out whether I've been rebuilt before.... I have about 28k and seem great all around as far as I can tell.
 
i can't decide if i want to go ahead with the disassembly or put it back together and sell it on CL as a non running bike. this is a tough decision.
 
Replacing the front guide isn't much more work than getting the head off. The only way it won't run when it's back together is if the cam isn't in the right position. That's easy to prevent even if you don't know how to find TDC, you take a pic of the cam before you take the chain off, and be careful not to turn the engine while the timing chain is off.
 
buy a clymers a follow it...easy peasy. I did my first one 4 years ago with no prior engine work experience before hand. Did my first honda SOHC 2 years ago. And another XS this year (my new project) if you have torque wrench, ratchet and socket set your set.

Take plenty of pics when you tear it down, bag and tag every thing. and follow your manual step by step. even timing these things is easy peasy. I honestly don't see how people manage to screw that part of it up and get the cam timing off. All the marks are there....if all the marks don't line up why peen the cam chain master link then put it back together????

Another thing....Any old bike you buy is a work trap...Out of like 10 bikes i have owned only 2 havent needed work....those 2 were new. So learn it yourself. hell my KLR is a 93 and even though it looks good and rode good i had to do a ton of work to it to make it road worthy for touring.
 
i can't decide if i want to go ahead with the disassembly or put it back together and sell it on CL as a non running bike. this is a tough decision.

LOL! It's more work to sell it than to fix it. Don't sell it unless you were going to sell it before.
 
to add insult to injury: as i was turning the engine over last night to find TDC so i could commence with the head removal i noticed something horrendous. oil is leaking from the front of the engine where the jugs meet the bottom end. i was already paranoid about taking the head off and now the jugs too! at least that explains why there is oil all over the front of my engine and it's lack of compression.

now i'm really thinking about selling.
 
xjwxm, about 150 lbs is optimal compression on one of these, about 130 or above and they'll run alright. An original motor with 20K+ miles can still have that optimal reading if the rings, bores, and valve seats are in good shape. The big concern now on most of these motors is that front cam chain guide. They're failing because of their age mostly, not because the part was defective. Lack of routine cam chain adjustments is also a factor here. That was bad for both the chain and the guide. That's why most of the chains are shot at 20K, too. If you have a points model, a good indication that the chain has stretched out and reached the end of it's useful service life is when you run out of adjustment slot on your timing plate. The cam chain should be checked and adjusted if need be about every 1000 miles. Most were never serviced that frequently.
 
Back
Top