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Smoke on startup

10K views 45 replies 7 participants last post by  Schoen 
#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?
 
#2 ·
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. :(
 
#3 ·
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
 
#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?
 
#5 · (Edited)
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.
 
#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.
 
#8 ·
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
 
#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?
 
#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.
 
#13 ·
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'.
 
#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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#16 ·
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
 
#17 ·
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.
 
#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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#18 · (Edited)
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.
 
#22 · (Edited)
A sharp AWL and some patience or even a pencil ERASER and some patience many unscrew the broken stub.

I'll suggest to NOT USE any RH rotation drill bit on it! Purchase a set of LH drill bits if the above tips are un-successful.

The threads should be 'perfectly fine'. JUST Don't bugger up the exposed aluminum above the broken stub!!!!!
 
#23 · (Edited)
Sorry to see that dutchman, but it was certainly no surprise.

The good news is that your dutchman is not preloaded, so it should be fairly easy to remove. However, take no short cuts when preparing for its removal. If it were me I would first take a Dremel tool with a small globe-shaped stone and make a dimple about 1/16" deep in the center of the broken face of the dutchman. Then using a hammer and a sharp prick punch make a sharp dimple in the center of the previously made dimple. Next using an appropriately sized drill bit for the "Easyout" you selected, drill a hole using the prick punch dimple as a centering guide. Insert the Easyout into the hole you just drilled and give it a light tap with a hammer. Lastly, using a wrench, start rotating the Easyout to the left and the dutchman should come right out.

I would then drill, tap and install a Hellicoil sized to match the thread on the valve cover bolt. Obviously you'll need to buy an new bolt from Kawasaki. Lastly, I would buy new sealing washers for the valve cover bolts, and perhaps a new valve cover gasket.

Of course before grinding, drilling and tapping, you need to take whatever means necessary to keep debris out of the head. Probably stuff some rags around the area you will be working on.

Jason
 
#26 ·
There is a good chance that now that the bolt is not under load it will turn out with very little torque. Using your center dimpling suggestion and the left handed drill bit that pdwestman suggested the bolt will likely come out with the torque from the left handed bit biting in as it cuts down. It might even come out by tapping counter clockwise with a sharp punch.
 
#24 ·
Well, I guess Paul was responding while I was typing my response.

I'm not sure why a right-hand drill bit would be a bad thing.

And I would take no chances with the threads, as I feel confident they have been compromised. A Helicoil repair is not too expensive or difficult and produces quality results, so why not do it?

Jason
 
#25 ·
A right hand drill bit may snag and screw the stub IN farther & Harder. A Left hand drill bit may snag & simply un-screw the stub.

I'm confident that the original threads are NOT compromised, otherwise the stub wouldn't have broken, the threads would have stripped.

The sealing washers & valve cover gasket need to be torqued to a Mere 60-70 INCH pounds, or just snug. The elasticity & grip of the rubber parts keeps the bolts from backing out.
 
#27 ·
A right hand drill bit may snag and screw the stub IN farther & Harder. A Left hand drill bit may snag & simply un-screw the stub.

I'm confident that the original threads are NOT compromised, otherwise the stub wouldn't have broken, the threads would have stripped.
The torque via a right-hand drill bit is negligible. The most important aspect of drilling ANY hole in the dutchman is to make damn sure it's in the center, hence my two-step process.

Regarding the condition of the threads, I typically see the threads at this particular location stripped rather than the bolt twisted apart. Seeing the broken bolt highly suggests that the female threads have been subjected to stresses beyond the yield strength of the relatively soft aluminum material. So why take a chance on trying to re-use them when it's easy to make a quality repair?

Jason
 
#30 ·
The broken stub really should NOT be bottomed out. And we do NOT want to 'jam' it in by using a RH drill bit.

I should have suggested the pencil eraser FIRST! Then the sharp awl. Then the LH drill bit. Then the easy out, which is never 'easy'!

And I'm trying to prevent having to use rags & vacuum cleaner & drills and untold time to fix what may be a Very SIMPLE problem, if approached with care & forethought.
 
#31 · (Edited)
I very much appreciate EVERYONE'S thoughts and suggestions. I called the local dealer to see if they had a bolt in stock. Of course, since it was late afternoon Saturday and they're closed Sunday and Monday, they don't have one but will gladly order one for me - when they reopen on Tuesday. So I may get back to the broken bolt tomorrow or later during the week since the new bolt won't be arriving until Friday or Saturday. :mad0235:
 
#33 · (Edited)
Took some pics of both right side valve cover bolt studs. I was prompted to do this because Norton 850 thought my original pic of the broken off bolt-in stud looked like it was possibly stuck in an insert (i.e., a previous thread repair). The first pic below is the right rear stud and, if that's a thread repair insert, it is well off center and has a peculiar spiral pattern on the top. The second pic is of the right front stud (the one that has become the subject of this thread). By the way, the right front stud insert that we've been talking about is flush with the base metal.

1. Can anyone confirm that the right side valve cover bolt studs do not come from the factory like this?

2. Assuming these are steel inserts, I think we now know how the bolt was broken off as opposed to the female threads just stripping out. Does anyone recognize what kind of inserts these are?

3. Again, assuming these are steel inserts, are there any changes to the earlier suggestions on getting the broken bolt out - now that we know steel is gripping steel? Use penetrating oil? Or don't?

Once I get it out, I'll hopefully be able to look within the stud/insert and see if there's something in the bottom that prevented the broken bolt from tightening all the way down. By the way, the right front stud "insert" is flush with the top of the aluminum stud. But there is a very slight height difference with the rear left insert vs stud.
 

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#34 ·
Schoen, I'm sure that those are NOT inserts into either of those stud towers. That is only the pattern of the flat base of the special, stepped oem bolts.

Just use a magnet on the un-damaged aluminum tower to confirm or refute my suggestion. And then the tower with broken steel stub.
 
#36 ·
Have you noticed the oil drain hole near that mounting tower?

It drains camshaft oil past the valve springs & stems and down thru the cam chain tunnel to the balancer chain & sprockets, crank bearing & flywheel. I would suggest plugging it with a cork before any drilling.

I would secure a vacuum cleaner hose very close to the tower to suck up as much chips as possible while drilling.

Are you certain that a pencil eraser or sharp awl can't turn the broken stub at all?

I would use an 1/8th" LH drill bit if I had to resort to drilling.
 
#38 · (Edited)
Have you noticed the oil drain hole near that mounting tower?...I would suggest plugging it with a cork before any drilling.

I would secure a vacuum cleaner hose very close to the tower to suck up as much chips as possible while drilling.

Are you certain that a pencil eraser or sharp awl can't turn the broken stub at all?

I would use an 1/8th" LH drill bit if I had to resort to drilling.
1. I didn't have a cork, but do sleep with earplugs at night. One of those worked.
2. Since my vacuum wanted to suck up my rags, I placed a magnet right near where I was drilling. That seemed to catch about 99% of the filings.
3. Triple checked with the eraser and sharp awl - wouldn't budge it.
4. Started with Norton 850's suggestion, using a very small rounded Dremel bit to carve out a small concave area, then hit the center of that with a sharp punch to indent and prepare for drilling (if at this point I had thought to quadruple check with an eraser or sharp awl, I might have gotten a different result - because of the whack I gave it). Then started drilling with a LH 1/16 drill (the bolt is very hard metal), and moved up to a LH 5/64 drill which eventually "snagged" and started backing out the broken bolt. I was doing all that to prepare to use the extractor bit (harbor freight's version of an EasyOut). Didn't have to.
 
#39 ·
I ran the good bolt into the threads, they seem to function about the same as the rear threads (right rear stud tower). It also firmly seats against the top of the stud. So, still not sure how/why it broke where it broke. Waiting for new bolt. To be safe, I also ordered all new bolt gaskets and valve cover gasket.
 
#40 ·
Glad that it is "outta' there"!!

I think that too many people forget to re-set their 1/4 drive inch pound torque wrench from 106 in lb for the cam bearing caps, down to 60 - 70 in lb for the valve cover bolts. ;)

And I wish that the valve cover bolts were only 10mm hex heads so I wouldn't have to change sockets and to encourage a 'gentler hand' by those that don't/won't use a torque wrench.

I would only use either contact cement or RTV sparingly in the groove of the valve cover to retain the gasket.
I do NOT use any RTV on the head to gasket surface, not even at the half-moons or "eye-balls". And have never had a leak, with a pliable gasket.
 
#41 ·
Yay! Glad to see the happy ending to that story!

The former owner's behavior is disgraceful He obviously realized that he broke the bolt, or thought that he stripped the thread and sold the problem on, rather than deal with the problem himself. Otherwise, his mechanic, (who may have done the mod to the cylinder head) was a dishonest cowboy!

I just looked at this thread for first time . Great to see it worked out for you.

Once again i feel inspired to comment on what a great online community this forum is. We done to all those who contributed to this successful outcome!

Cheers

matthew
 
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