2008 won’t idle, tried a bunch, weird issues

johnkol wrote:

Flynavy wrote:

Interesting to note with key on the turn signals are lightly lit at all times.  Headlight not working, when we crank it, headlights come on.  Maybe symptom of a weak battery?

No, that's how the WRR works: turning the key to the on position the front turn signals (but not the rear) turn on and serve as extra lights; the headlight will not turn on until the engine starts (safety measure to avoid draining the battery).

Flynavy wrote:

Cleaned up wiring harness and put it all back together for its maiden voyage.  Wouldn’t start.  NOTHING significant changed from start, assembly, to start.

I suspect that "cleaning up the wiring harness" is the root of the problem. Maybe there is a frayed wire contacting either the frame or another wire? Or simply an intermittent connection somewhere?

Two other data points, when I went to start in driveway the hour meter showed 8 hours, it’s always been 12 up until now.  The low fuel thing showed up where it’s a trip counter so you know how far you’ve gone.

Back in the garage, hour meter back to 12, no low fuel.

Unplug CPS connector, bike still cranks… definitely threw the proper code last night when testing it.

I am the greatest mechanic alive. I kid I kid.

Ok so ECU appears to be working as it should, I wasn’t patient enough. If I crank engine, CPS code does get thrown after a few seconds, check.

At this point I’m thinking what if timing skipped a tooth? So I gently cracked valve cover and checked, chain and timing good.

Then on a wild whim said screw it and put the crust old plug that came with my used head in. Keep in mind up until this point I’ve only been using the one I bought new. This one has been used through all my troubleshooting and maybe fouled out?

Anyways… bike fired right up like it did last night.


Please explain this to me like a toddler… is it actually possible for a plug to go bad from fouling it out? I always assumed you just wipe it clean and it’s fine. It had good spark, my friend did say he would normally expect a more blue spark though.

You have an aftermarket hour meter? Usually these are connected to the ignition coil, is this how yours is connected too? I have no explanation for the hour meter showing different numbers, but if your driveway is inclined, that would affect the fuel level and hence the fuel sensor could show a different reading.

If the CPS is unplugged, the ECU will not receive a timing signal so it won't be able to provide spark, so that makes sense.

Generally speaking spark plugs don't foul on 4-stroke engines; the fuel mixture would have to be way, way off for crud to accumulate on the tip to prevent a good spark. For the extremely limited time you used the new spark plug, I would have thought that it would be impossible for it to fail; is there an unusual accumulation of soot on the tip?

BTW, are you using a standard plug or an iridium one? Standard plugs usually need to have the gap adjusted, did you check that? If you are using iridium, these usually come pre-adjusted.

johnkol wrote:

You have an aftermarket hour meter? Usually these are connected to the ignition coil, is this how yours is connected too? I have no explanation for the hour meter showing different numbers, but if your driveway is inclined, that would affect the fuel level and hence the fuel sensor could show a different reading.

If the CPS is unplugged, the ECU will not receive a timing signal so it won't be able to provide spark, so that makes sense.

Generally speaking spark plugs don't foul on 4-stroke engines; the fuel mixture would have to be way, way off for crud to accumulate on the tip to prevent a good spark. For the extremely limited time you used the new spark plug, I would have thought that it would be impossible for it to fail; is there an unusual accumulation of soot on the tip?

BTW, are you using a standard plug or an iridium one? Standard plugs usually need to have the gap adjusted, did you check that? If you are using iridium, these usually come pre-adjusted.

Did not check gap, the tips look a little wonky too, this is how it came from the store new.  I get what you’re saying for sure.  Someone else said the resistance could be bad from running rich so much.  Honestly who knows at this point, because this plug worked great yesterday.  Was it just enough to go bad today?

The hour meter stuff, I honestly have no idea.  I know these bikes have trip counters but I didn’t dig too much into it.

OK, this is a standard double-electrode plug, it comes pre-gapped so no issue there. It looks good to me, there is no accumulated soot or crud, the failure must be internal.

Flynavy wrote:

Someone else said the resistance could be bad from running rich so much.

The resistance increases because crud accumulates on the electrodes; there is no such accumulation on yours, that's why it must be something internal that has failed.

The WRR has two trip meters, but no hour meter; if you have an hour meter it must be an aftermarket device.

johnkol wrote:

OK, this is a standard double-electrode plug, it comes pre-gapped so no issue there. It looks good to me, there is no accumulated soot or crud, the failure must be internal.

Flynavy wrote:

Someone else said the resistance could be bad from running rich so much.

The resistance increases because crud accumulates on the electrodes; there is no such accumulation on yours, that's why it must be something internal that has failed.

The WRR has two trip meters, but no hour meter; if you have an hour meter it must be an aftermarket device.

Hmm, makes sense… 

First test run complete.  Bike drives and runs good.  I went around the block, definitely feels hot after and smells a little.  Now at this point I could be all in my head but I do have a stock 08 to compare to.  I’m not sure, maybe radiator?  Is there an actual way to see if it’s circulating?

I know I’ll need to check fan relay.  At least in diagnostics mode I can’t get it to come on.

If the bike is moving, the fan should never come on, especially during winter. If you want to force the fan to come on, just idle the bike while monitoring the coolant temperature through Diagnostic Code 06; it should come on around 210 F.

If you suspect the coolant temperature sensor to be off, you can check it by following the procedure on Page 8-78.

johnkol wrote:

If the bike is moving, the fan should never come on, especially during winter. If you want to force the fan to come on, just idle the bike while monitoring the coolant temperature through Diagnostic Code 06; it should come on around 210 F.

If you suspect the coolant temperature sensor to be off, you can check it by following the procedure on Page 8-78.

Easy fix, we never added coolant.  I could write a book on lessons learned for this one.  We were both assembling and it was overlooked, oof!

Still curious on how the hour meter functions.  You mentioned it must be aftermarket but this is the stock unit, and my other WR is the same.  Turn the key on, and there’s hours ticking away on the top line.  Some times it’s 4 something, others it’s 12… maybe it resets with key on and off? Can’t seem to find anything on it.

Flynavy wrote:

Easy fix, we never added coolant.

Yikes! Good thing you didn't take my advice to go on a long ride!

Flynavy wrote:

Turn the key on, and there’s hours ticking away on the top line.

That's not an hour meter, it's just a clock.

johnkol wrote:

Flynavy wrote:

Easy fix, we never added coolant.

Yikes! Good thing you didn't take my advice to go on a long ride!

Flynavy wrote:

Turn the key on, and there’s hours ticking away on the top line.

That's not an hour meter, it's just a clock.

Sorry, I’ve been too embarrassed to respond haha.  Well that makes sense.

Bike is cleaned up.  Tightened up some coolant leaks, she’s looking real nice.

I’m committed to selling this in good conscience and good condition.  So this exhaust is missing the end cap, little cone thing.  A 98.00 oem part go figure.  If you have any leads on one I’ll be forever grateful.  Updated pics coming your way soon.

You mean Item 13 in this Parts Diagram? I don't know where you could find that by itself, I'm sure you can find a used muffler on eBay, but it would be more expensive than $96. Maybe get the used muffler, use the cap on yours, and sell the rest as parts?

johnkol wrote:

You mean Item 13 in this Parts Diagram? I don't know where you could find that by itself, I'm sure you can find a used muffler on eBay, but it would be more expensive than $96. Maybe get the used muffler, use the cap on yours, and sell the rest as parts?

You know this isn’t fun without more issues… new tires on.  All bolted up.  Coolant still leaking, tighten another nose near the actual radiator.  Now it’s leaking from cylinder head.  Unless I’m crazy and it’s running down along some other surface and appearing so, I was 80% sure.  Well at least I can tear into this thing quick now.  About two hours to remove valve cover, tighten bolts more, re time and assemble.

Probably make you cringe but I didn’t tighten to spec first go.  I don’t trust my torque wrench.  So I tried with it just now, with baby increments.  20lb feels like a lot, like I’m going to break a bolt.  I’d say each bolt took another half turn ish.  Dumb to ask but is that enough difference to allow coolant to leak?

Almost seemed like tightening the hose that was leaking allowed pressure into “weak” or “loose” areas of the head.  Does any of this make any logical sense?

Pic is where it was leaking, the little pry point.

Flynavy wrote:

Coolant still leaking

What do you mean by "still"? You hadn't mentioned any leaking problems, was it leaking before you removed the cylinder head? I presume when you installed the new cylinder head you put a new gasket in?

Flynavy wrote:

I’d say each bolt took another half turn ish.  Dumb to ask but is that enough difference to allow coolant to leak?

Half a turn is a lot, so the leak could definitely be due to under-tightening. The main problem with under-tightening is not coolant leaking, but compression gas from the cylinder blowing through the gasket and permanently damaging it. If this has happened, then tightening it to spec will not solve the problem and you will not to replace the gasket. If there are no more leaks after correctly tightening the head bolts, then you don't have to worry about it.

Tightening the hoses shouldn't result in coolant leaking from other areas. In general, coolant is not under pressure until the engine warms considerably, did you run the engine long enough to reach normal operating temperatures?

As far as torque forces are concerned, it all depends on the length of the wrench: if you're using a 6" wrench, then 20 ft-lbs will feel like a lot of force, whereas if you are using a 16" wrench, 20 ft-lbs will feel very mild. I have a few mechanical torque wrenches, but I also have a digital torque gauge that I use to make sure the mechanical wrenches are calibrated accurately. A digital torque gauge is not that expensive, so if you're planning on wrenching on your bikes, it's a good investment.

johnkol wrote:

Flynavy wrote:

Coolant still leaking

What do you mean by "still"? You hadn't mentioned any leaking problems, was it leaking before you removed the cylinder head? I presume when you installed the new cylinder head you put a new gasket in?

Flynavy wrote:

I’d say each bolt took another half turn ish.  Dumb to ask but is that enough difference to allow coolant to leak?

Half a turn is a lot, so the leak could definitely be due to under-tightening. The main problem with under-tightening is not coolant leaking, but compression gas from the cylinder blowing through the gasket and permanently damaging it. If this has happened, then tightening it to spec will not solve the problem and you will not to replace the gasket. If there are no more leaks after correctly tightening the head bolts, then you don't have to worry about it.

Tightening the hoses shouldn't result in coolant leaking from other areas. In general, coolant is not under pressure until the engine warms considerably, did you run the engine long enough to reach normal operating temperatures?

As far as torque forces are concerned, it all depends on the length of the wrench: if you're using a 6" wrench, then 20 ft-lbs will feel like a lot of force, whereas if you are using a 16" wrench, 20 ft-lbs will feel very mild. I have a few mechanical torque wrenches, but I also have a digital torque gauge that I use to make sure the mechanical wrenches are calibrated accurately. A digital torque gauge is not that expensive, so if you're planning on wrenching on your bikes, it's a good investment.

I’m all over the place, let me try to clean this up…


- radiator had some leaks after the re build.  Obvious hose areas, tightened them all up, continued buttoning everything up.  

-ran bike at idle, saw another leak, top hose going into the radiator.  I tightened it down, tested bike again.  Appeared coolant was dripping from that area in the photo.  Slow but steady.

-tore it all down and tightened down.  Drained oil, it definitely had coolant in it, you could see it separated.


Now to rewind, I did spill coolant all in the crank weeks ago, long story and lesson learned.  Maybe some residual from that, or from the head leaking?

I plan on running the bike and draining oil to check current status.

I went down a rabbit hole on over pressurizing the system and its relation to blowing gaskets.  I’m hoping I’m in the clear and over thinking it all but not white sure what to check next.

Flynavy wrote:

I went down a rabbit hole on over pressurizing the system and its relation to blowing gaskets.

I'm not exactly sure how one can over-pressurize the cooling system, but in general the cooling system is not under a lot of pressure, certainly nowhere near the pressures inside the cylinder that are typically two orders of magnitude greater.

If the hoses were reasonably tightened with hose clamps, there shouldn't have been any leaks, so you may want to check whether you have the correct diameter hoses.

Now that you have tightened all the bolts and hoses, what is the status? Are there any leaks from the cylinder head or the hoses? Do you still see coolant in the oil?

johnkol wrote:

Flynavy wrote:

I went down a rabbit hole on over pressurizing the system and its relation to blowing gaskets.

I'm not exactly sure how one can over-pressurize the cooling system, but in general the cooling system is not under a lot of pressure, certainly nowhere near the pressures inside the cylinder that are typically two orders of magnitude greater.

If the hoses were reasonably tightened with hose clamps, there shouldn't have been any leaks, so you may want to check whether you have the correct diameter hoses.

Now that you have tightened all the bolts and hoses, what is the status? Are there any leaks from the cylinder head or the hoses? Do you still see coolant in the oil?

I refilled oil and ran the bike at idle for about 10 minutes.  Felt like it got hot, but it’s at idle so maybe normal? Hit around 200 degrees sitting there at idle for that long.  Oil sight glass didn’t look suspicious or milky, plan to take around the block, drain and check oil, and go from there.  I’m not terribly hopeful tightening fixed it, seems too good to be true.

At idle at least, I didn’t see any leaks.  I did initially see some seepage from same area, but I think it was whatever last bit was smushed in there getting out.

Reaching 200 F after idling for 10 minutes seems reasonable.

Your plan is sound, take it out for a longer spin, check to see if there are still leaks, do an oil change to see if there is coolant contamination.

johnkol wrote:

Reaching 200 F after idling for 10 minutes seems reasonable.

Your plan is sound, take it out for a longer spin, check to see if there are still leaks, do an oil change to see if there is coolant contamination.

Just drained oil.  Don’t see coolant in it, but can’t tell if this is a normal look for relatively new oil.  Had some fine bubbles in it, this was after a 3 minute idle.

Also important to note, it’s very possible I overfilled the oil.   Seems like it was at the top of the mark if not over.

Bike doesn’t want to idle perfectly like it did before I dug into it again.  Will idle all day, but sometimes die off idle.

Question… this new throttle body has the adjustment screw direct to the idle stop (not the little gold air screw).  I can’t remember where I had it before but it doesn’t want to run with screw out or basically natural idle stop.  Is that normal? Obviously runs fine when I crank the idle up a tad.

This oil looks green-ish to me; what's the colour of the coolant you're using? Overfilling would have had no effect.

You had said earlier that the idle screw had been working again, but I can't remember whether that statement was for the old throttle body or the new one. So now you're using the new one and it only idles with the screw all the way in? And if you back it off the engine dies?

johnkol wrote:

This oil looks green-ish to me; what's the colour of the coolant you're using? Overfilling would have had no effect.

You had said earlier that the idle screw had been working again, but I can't remember whether that statement was for the old throttle body or the new one. So now you're using the new one and it only idles with the screw all the way in? And if you back it off the engine dies?

Green coolant, but for the first oil drain the coolant was very apparent and obvious and sank to the bottom of the bottle.  For this drain pictured, there is nothing at the bottom.

As far as idle screw, I’m not talking about the idle screw you are.  I’m talking about an aftermarket deal where it’s literally a screw pushing the idle stop in or out.  So all the way out, it will die on me.  I bump it ever so slightly in, bike will run forever.

Flynavy wrote:

As far as idle screw, I’m not talking about the idle screw you are.  I’m talking about an aftermarket deal where it’s literally a screw pushing the idle stop in or out.  So all the way out, it will die on me.  I bump it ever so slightly in, bike will run forever.

I've never heard of such a contraption, I can't even picture how it was integrated into the throttle body. I suppose you can set it where it works, but I don't know how that would affect other aspects of the engine.

johnkol wrote:

Flynavy wrote:

As far as idle screw, I’m not talking about the idle screw you are.  I’m talking about an aftermarket deal where it’s literally a screw pushing the idle stop in or out.  So all the way out, it will die on me.  I bump it ever so slightly in, bike will run forever.

I've never heard of such a contraption, I can't even picture how it was integrated into the throttle body. I suppose you can set it where it works, but I don't know how that would affect other aspects of the engine.

I just looked at the stock bike, it has it too.  Can’t really get a good picture.  But when you let go of the throttle, the throttle comes back to idle and rests against a metal stop.  Stock bike has a half inch screw, pushing out about half an inch, essentially setting the idle stop.  So if I were to unscrew the stock bike one, it would probably die too.  I’ll try to get a pic eventually.


I just ran it again for a while.  I’m really losing my mind here.  Is it even possible to have such a slow leak that after 10 minutes of idling and then cooling you can see the tiniest bit of shine on the gasket?

I understand the mechanical throttle stop you describe, can't remember whether I ever adjusted it; whenever I wanted to adjust the idle speed I always used the idle screw. If it holds idle at the specified RPMs, I don't think it matters whether you achieved this through the idle screw or the throttle stop.

If the only leak you see is the gasket getting shiny, then I wouldn't worry about this. However, I would want to confirm that this holds true even after an extended ride.

johnkol wrote:

I understand the mechanical throttle stop you describe, can't remember whether I ever adjusted it; whenever I wanted to adjust the idle speed I always used the idle screw. If it holds idle at the specified RPMs, I don't think it matters whether you achieved this through the idle screw or the throttle stop.

If the only leak you see is the gasket getting shiny, then I wouldn't worry about this. However, I would want to confirm that this holds true even after an extended ride.

I have more questions…

Radiator cap currently on is a 1.8, I understand stock is 1.1, I also have a basic understanding of the system.

When I idled bike for 10 minutes, I could see some steam coming from the cap.

When I finally learned how a radiator works, I realized my overflow is bone dry.  So I filled it up just below the top line per the manual.

Ran the bike again, had a slow drip coming from the black tube (overflow tube?).

What am I missing? I’ve ordered a stock cap, but the more research I do the more it leads to scary outcomes of blown head gaskets.

I use an aftermarket radiator cap that is also rated for 1.8 bar, so that's not a concern. Irrespective of the coolant level, there shouldn't be any steam coming through the cap, so a check is in order to verify that the cap O-ring and the radiator mating surface are making good contact.

The coolant overflow tube starts just below the radiator cap, crosses over the top of the frame, and goes into the coolant reservoir. There should be small hose clamps securing the overflow tube, are these there? If yes, and you still have a leak, then the overflow tube may have become brittle, so try a new one.

None of the above implies you have blown the head gasket, so I don't think you're missing anything.