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Discussion Starter #1
2008, 685 (supposedly), new to me. On startup, with choke on (toward rider), smoke billows up from the engine (haven't determined an exact location/source). Smoke goes away when choke lever gets pushed back. Any ideas why?
 

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I'll take a guess of possible oil leakage from the top valve cover drooling on to the exhaust header pipe when parked for a while & especially over night.

The exhaust header heats up pretty quickly, smoking the oil film. The thin film may just coincidentally be burned off by the time the engine is warm enough to idle without choke.

I'll strongly urge you to NOT simply try to tighten valve cover bolts to stop an oil leak. Too Many people strip the threads or twist off the bolts. This may already be the case & why it may be leaking from there! The bolts are only 6mm thread, with a stepped shoulder and an OVERLY Large 12mm head which encourages people to over-tighten, 12mm head is usually on a 8mm shank. :(
 

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I'll strongly urge you to NOT simply try to tighten valve cover bolts to stop an oil leak. Too Many people strip the threads or twist off the bolts. This may already be the case & why it may be leaking from there! The bolts are only 6mm thread, with a stepped shoulder and an OVERLY Large 12mm head which encourages people to over-tighten, 12mm head is usually on a 8mm shank. :(
I'll echo Paul's suggestion regarding the valve cover bolts. It is super easy to strip these dinky fasteners, even with a torque wrench!

Jason
 

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Discussion Starter #4
Thanks for replies/thoughts. The previous owner has silicone glue running a circumference around the valve cover gasket edge and the other gasket edge below (said he had a little oil seepage after the 685 upgrade). So you all may be on to something. Assuming I choose to pull the top off and install new gaskets and retorque, do I need to pull the motor out, or can it be done in the frame without an inordinate amount of trouble?
 

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Thanks for replies/thoughts. The previous owner has silicone glue running a circumference around the valve cover gasket edge and the other gasket edge below (said he had a little oil seepage after the 685 upgrade). So you all may be on to something. Assuming I choose to pull the top off and install new gaskets and retorque, do I need to pull the motor out, or can it be done in the frame without an inordinate amount of trouble?
The Best Thing that you can do for your bike & yourself is to Purchase a Clymer or OEM service Manual. (But not a slightly used oem 99924-1384-01 OEM service manual off any net site. Too Many ERRORS in 1st printing)

Yes, the top-end can be serviced in-frame.
 

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Thanks for replies/thoughts. The previous owner has silicone glue running a circumference around the valve cover gasket edge and the other gasket edge below (said he had a little oil seepage after the 685 upgrade). So you all may be on to something. Assuming I choose to pull the top off and install new gaskets and retorque, do I need to pull the motor out, or can it be done in the frame without an inordinate amount of trouble?
As Paul said, no need to pull the motor out of the frame.

If you do have stripped threads in the cam caps, they can be repaired via Helicoil.

I do not recommend using a torque wrench for installing the valve cover bolts. Torque is not a very accurate means of preloading a fastener, as small variations in friction translate into big changes in preload. Instead, I would torque the valve cover bolts by feel. Slowly tighten the bolts in a cross-pattern. You will fee the gasket compressing as you turn the wrench. The moment you feel that the gasket has stopped compressing and you feel metal-to-meal contact as the bolt torque shoulder makes contact with the cam caps, STOP tightening.

And lastly, get a workshop manual--if you don't already have one.

Jason
 

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Discussion Starter #7 (Edited)
This is the first I've heard of Helicoil. So I searched it, watched a couple videos, and found a thread or two here where it seemed to solve the stripped thread problem (don't know if they experienced leaking). Assuming I have stripped internal threads:
1. Is the purpose of the Helicoil so you can reuse of the stock bolts? If so, why would you want to reuse the stock bolts if they are "dinky"?
2. Is there any benefit in using the Helicoil instead of just drilling/tapping to the next size up which, I would think, would get me a better/stronger bolt than those "dinky fasteners"? I already had to do this with the rear brake lever pinch bolt (previous owner overtightened it and stripped the internal threads). Tapping to a slight oversize worked fine for securing the brake lever but, then again, it's not being used to make a seal and keep oil inside. Does the Helicoil insert allow you to tighten more confidently (without the worry of stripping)? I found an opinion in one of the threads that there might not be enough metal for drilling/tapping...Has anyone confirmed this? But, if you're having to drill for the Helicoil...?
3. Does anyone make better/stronger/larger valve cover bolts to deal with what is starting to sound like a common problem? The sub-frame bolts were deficient, so there's an upgrade for that. The front brake reservoir Philips head screws get stripped out so Eagle Mike makes replacement hex-head screws. But, from looking at his website, it don't see anything for this problem.

For a failed Helicoil report, go to the advrider.com forum and search for KLR 650 Valve Cover bolt - New Threat! Has good pics of the fix (stud implantation). Hope I don't have to go to that extent.

My bike came with an old Clymer manual. When I get home, I'll look and see which edition it is.
 

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This is the first I've heard of Helicoil. So I searched it, watched a couple videos, and found a thread or two here where it seemed to solve the stripped thread problem (don't know if they experienced leaking). Assuming I have stripped internal threads:
1. Is the purpose of the Helicoil so you can reuse of the stock bolts? If so, why would you want to reuse the stock bolts if they are "dinky"?
2. Is there any benefit in using the Helicoil instead of just drilling/tapping to the next size up which, I would think, would get me a better/stronger bolt than those "dinky fasteners"? I already had to do this with the rear brake lever pinch bolt (previous owner overtightened it and stripped the internal threads). Tapping to a slight oversize worked fine for securing the brake lever but, then again, it's not being used to make a seal and keep oil inside. Does the Helicoil insert allow you to tighten more confidently (without the worry of stripping)? I found an opinion in one of the threads that there might not be enough metal for drilling/tapping...Has anyone confirmed this? But, if you're having to drill for the Helicoil...?
3. Does anyone make better/stronger/larger valve cover bolts to deal with what is starting to sound like a common problem? The sub-frame bolts were deficient, so there's an upgrade for that. The front brake reservoir Philips head screws get stripped out so Eagle Mike makes replacement hex-head screws. But, from looking at his website, it don't see anything for this problem.

For a failed Helicoil report, go to the advrider.com forum and search for KLR 650 Valve Cover bolt - New Threat! Has good pics of the fix (stud implantation). Hope I don't have to go to that extent.

My bike came with an old Clymer manual. When I get home, I'll look and see which edition it is.
The dinky bolt doesn't fail, the aluminum female thread does.

The Helicoil repair will accommodate slightly higher tension loads. The Helicoil does this by providing slightly greater shear area in the aluminum base material and the Helicoil's stainless steel material has greater yield strength than aluminum.

A larger diameter bolt would make for a stronger connection. But, the larger bolt would have to have a unique geometry similar to the stock bolt, as the stock bolt has several upset diameters that are not found on hardware-store-type bolts.

So, I recommend a Helicoil repair instead of trying to use an oversized bolt.

Of course all this assumes that the threads used to secure the valve cover bolts are stripped. Have you investigated the root cause of your smoky startup?

Jason
 

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The dinky bolt doesn't fail, the aluminum female thread does.

The Helicoil repair will accommodate slightly higher tension loads. The Helicoil does this by providing slightly greater shear area in the aluminum base material and the Helicoil's stainless steel material has greater yield strength than aluminum.

A larger diameter bolt would make for a stronger connection. But, the larger bolt would have to have a unique geometry similar to the stock bolt, as the stock bolt has several upset diameters that are not found on hardware-store-type bolts.

So, I recommend a Helicoil repair instead of trying to use an oversized bolt.

Of course all this assumes that the threads used to secure the valve cover bolts are stripped. Have you investigated the root cause of your smoky startup?

Jason
Excellent explanation. Simple answer; you can't use generic bolts for this application, the valve cover bolts are unique.

Dave
 

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Discussion Starter #10
Just figured out I need 15 posts before I can post pics of what appears to be the problem.
 

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Discussion Starter #11 (Edited)
5 more posts and I can post pics of what I found. For now, I'll try and describe.
Oil collecting on the bottom of the coolant hose (which is above the exhaust connection).
Oil on the bottom half of the exhaust bracket (that connects the exhaust pipe to the head.
And, under/behind the exhaust bracket where the exhaust bracket butts up against the head, there's a rectangular cutout that, almost looks like it's supposed to be that way but for the corner of the rectangular cutout is broken off. I need to find another KLR and look and see if it too has a rectangular cutout in the head connection under/behind the exhaust bracket. It looks like this could be where the oil is coming out: but why would oil be coming out of the exhaust port?
 

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Discussion Starter #12
Made it to 15 posts, uploaded pics, just waiting (I guess) for that to take, and then I'll post 'em. Going to swing by the local bike shop and see if there's a KLR there so I can look at the exhaust connection. Thanks for your patience and help with this.
 

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The rectangular open area is common to all KLR650 heads. The shiny corners are from the milling machine surfacing the head gasket area and those corners 'hang-down'.
 

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Discussion Starter #14 (Edited)
The rectangular open area is common to all KLR650 heads. The shiny corners are from the milling machine surfacing the head gasket area and those corners 'hang-down'.
Yep, discovered that at the bike shop where they still have a few KLRs to look at.
And just got my pics uploaded so I'll get them into this thread now.
 

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Discussion Starter #15 (Edited)
First Pic: oil collecting on the underside of the coolant hose, just above and to the left of the exhaust connection (probably running down to the left because of the bike resting on the kick stand). This is fresh oil.

Second Pic: oil on the underside of the exhaust bracket.

Third Pic: under and behind the exhaust bracket. Arrow pointing to the rectangular cutout (which I've since learned is meant to be there) which has a broken off corner, partly visible.

Will spend some more time tonight to see if I can pinpoint where the oil is coming from. Didn't have a whole lot of time when I was taking these pics and was not dressed appropriately for foraging.
 

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First Pic: oil collecting on the underside of the coolant hose, just above and to the left of the exhaust connection (probably running down to the left because of the bike resting on the kick stand). This is fresh oil.
Second Pic: oil on the underside of the exhaust bracket.
Third Pic: under and behind the exhaust bracket. Arrow pointing to the rectangular cutout (which I've since learned is meant to be there) which has a broken off corner, partly visible.
Will spend some more time tonight to see if I can pinpoint where the oil is coming from. Didn't have a whole lot of time when I was taking these pics and was not dressed appropriately for foraging.
Can you follow the oil trail up from the exhaust flange to the joint between the head and the valve cover? My first guess is that there is a valve cover gasket leak directly above the exhaust pipe connection at the head. For a closer inspection of the valve cover gasket you may need to remove the gas tank.

Perhaps you've already done this? If not, you should consider doing it now.

Jason
 

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Once the fuel tank is removed, the source may be quickly spotted. I'll guess the RH forward valve cover mounting bolt & its rubber gasket.

Even if the source is readily found, plug the fuel hose & fuel tap vacuum hose and using a degreasing product (like Gunk Engine Brite) and water to rinse (Hot water if you can), proceed to thoroughly degrease & de-mud the entire bike. Especially the top of the engine & around the spark plug. There is spark plug well drain hole below the thermostat housing, use a wire or even a drill bit to clean it out.

With a thoroughly clean & DRY engine, if necessary one can spray a white or gray drying Cheap Foot Powder around the suspect area. It will stain very quickly upon start up to show leakage area.
 

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That head/valve cover seal is a big thick rubber gasket and there is not much pressure under the cover because it is vented to the crankcase which is vented to the clean air box. So, not much pressure is required from those four head cover bolts to seal that big rubber gasket. No sealant is necessary. Just make sure the surfaces on the head and the cover are clean as well as the area under the rubber seals on the four special bolts. Lightly snugged by hand feel is fine to make a good seal and not risk striping the threads in the head.

If you find stripped threads in the head for one of those bolts, it is easy to drill, tap and install a helicoil for the stock bolt. I did it using borrowed tools in a small motorcycle in Thunder Bay, Ontario on the way from Houston to Alaska. It was the mechanic's day off. I have no idea why it popped halfway to Alaska but, since I am the only guy who works on my bikes, it must have been my fault.
 

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Discussion Starter #19 (Edited)
Once the fuel tank is removed, the source may be quickly spotted. I'll guess the RH forward valve cover mounting bolt & its rubber gasket...
Yep, that's the one. I can even turn it a little bit with my fingers. Now I guess I find out if it's just the female threads that are stripped, or if he actually broke the internal stud the bolt screws into. You can see all the silicone glue he put around the gasket edge trying to keep the oil in.
 

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