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

You had mentioned that the previous owner had put in the wrong piston, but not that he had put in the 5-valve WRF piston! It would be very hard to imagine how only one valve was affected by this, and even harder to accept that the only casualty was a valve and not the associated seal and guide.

It's also concerning when you say that he replaced the damaged items with the cheapest stuff he could find. The WRR intake valves are made of titanium, with appropriate guide and seal tolerances, so I don't know how you replace these with a different material valve (e.g. steel) whose thermal expansion coefficient is much higher.

It is very difficult to measure valve stem runout or valve guide roundness; most shops don't have the necessary tools to even perform these measurements, that's why in most cases they simply replace all affected items.

johnkol wrote:

You had mentioned that the previous owner had put in the wrong piston, but not that he had put in the 5-valve WRF piston! It would be very hard to imagine how only one valve was affected by this, and even harder to accept that the only casualty was a valve and not the associated seal and guide.

It's also concerning when you say that he replaced the damaged items with the cheapest stuff he could find. The WRR intake valves are made of titanium, with appropriate guide and seal tolerances, so I don't know how you replace these with a different material valve (e.g. steel) whose thermal expansion coefficient is much higher.

It is very difficult to measure valve stem runout or valve guide roundness; most shops don't have the necessary tools to even perform these measurements, that's why in most cases they simply replace all affected items.

I agree. The previous owner said only one valve looks ever so bent so he replaced one. Pretty sure the other two are original based on the markings. I’m definitely tempted to throw correct piston in there and see. I’d just like a definitive answer on the top end valve stuff before doing so.

I agree that the best course of action is to just get OEM piston and rings and see where compression ends after this. If it's still low, then the entire valve train is suspect, and I don't know whether it's worth replacing individual items anymore.

johnkol wrote:

I agree that the best course of action is to just get OEM piston and rings and see where compression ends after this. If it's still low, then the entire valve train is suspect, and I don't know whether it's worth replacing individual items anymore.

More to follow. Can you confirm where this bike gets its actual RPM reading from? Replacing coil didn’t do anything to my weird error. Does the crankshaft sensor measure it?

Yes, the RPM information comes from the CPS.

johnkol wrote:

Yes, the RPM information comes from the CPS.

I’ll be removing valves soon to check them out. Just curious on the CPS though and what could be causing eradic readings.

I don't know what might be causing the high RPM readings; you checked the CPS and it was within specs, you swapped ECUs, so the only remaining suspect is the display itself (and the entire wiring system, but that's another story).

You can get a cheap RPM/hour meter from Amazon (that's what I have) and monitor the RPMs this way, but of course this doesn't solve the actual problem.

johnkol wrote:

I don't know what might be causing the high RPM readings; you checked the CPS and it was within specs, you swapped ECUs, so the only remaining suspect is the display itself (and the entire wiring system, but that's another story).

You can get a cheap RPM/hour meter from Amazon (that's what I have) and monitor the RPMs this way, but of course this doesn't solve the actual problem.

I never checked the CPS, I’ll need to do that when it’s assembled!

If the CPS resistance is too low, then it is possible for the CPS to pick up spurious signals from the rotor, but in that case I would have expected Fault Code 12 at some point. Of course you said that the ECU never throws any fault codes, which is another prooblem.

johnkol wrote:

If the CPS resistance is too low, then it is possible for the CPS to pick up spurious signals from the rotor, but in that case I would have expected Fault Code 12 at some point. Of course you said that the ECU never throws any fault codes, which is another prooblem.

Found another fun one. Can’t find what it is. It’s near rear fuses. Any ideas?

Is this a Blue/Green and a pure Black, or is the Black a Black/Green? These could be the wires for the sidestand switch. Is the sidestand switch still there?

johnkol wrote:

Is this a Blue/Green and a pure Black, or is the Black a Black/Green? These could be the wires for the sidestand switch. Is the sidestand switch still there?

Looks like black/green and blue/green to me. Switch is gone, remember that janky one up near the stator bundle? That appeared to be it as well.

I pulled valves. Why not. I don’t see anything obvious but I’m not a trained mechanic.

There is some seemingly uneven carbon deposits on the valve seats, but it's difficult to judge from the pictures; how does it feel when you run your finger over the valve seats, are they uniformly smooth?

The exhaust valve seats appear mangled; is that so, or is the angle of the picture making them look that way?

Flynavy wrote:

Looks like black/green and blue/green to me.  Switch is gone, remember that janky one up near the stator bundle? That appeared to be it as well.

The manual doesn't even list Black/Green as being used, so not sure what to make of this. If we view the Green as Yellow with dirt, then the combination Black/Yellow and Blue/Yellow is the clutch switch; can you crank the bike in gear without engaging the clutch?

johnkol wrote:

Flynavy wrote:

Looks like black/green and blue/green to me.  Switch is gone, remember that janky one up near the stator bundle? That appeared to be it as well.

The manual doesn't even list Black/Green as being used, so not sure what to make of this. If we view the Green as Yellow with dirt, then the combination Black/Yellow and Blue/Yellow is the clutch switch; can you crank the bike in gear without engaging the clutch?

I’ll have to try when assembled. Cleaned valve area, seats might be bad? Hard to see for you probably but look at left area of the right openings.

Right, both exhaust valve seats look damaged, plus the valve guide seems to have been shattered also, leaving a pentagon-shaped opening:

johnkol wrote:

Right, both exhaust valve seats look damaged, plus the valve guide seems to have been shattered also, leaving a pentagon-shaped opening:

I see the bad seats but I didn’t notice the guide. Welp.

200-400 to have repaired?

400-600 for a used top end?

I have an offer for a used rebuilt engine, 500.00 and I send mine to him.

Don’t know what to do, again.

I don't think the head can be repaired; it's not just the valve guide that has been damaged, some of the missing material is part of the head itself.

Used head? Do you trust the bottom end of the engine to be defect-free?

Used rebuilt engine? How much can you trust it? Moreover, $500 for it brings the total outlay to about $3,300? And you still have to solve all the electrical problems, and if you do, the bike still looks like beat to hell as you said.

On the other hand, how much can you get by parting the bike out? The engine is half-destroyed, many electrical components are suspect, is everything else in good condition?

johnkol wrote:

I don't think the head can be repaired; it's not just the valve guide that has been damaged, some of the missing material is part of the head itself.

Used head? Do you trust the bottom end of the engine to be defect-free?

Used rebuilt engine? How much can you trust it? Moreover, $500 for it brings the total outlay to about $3,300? And you still have to solve all the electrical problems, and if you do, the bike still looks like beat to hell as you said.

On the other hand, how much can you get by parting the bike out? The engine is half-destroyed, many electrical components are suspect, is everything else in good condition?

You make too much sense. I’ve had a few people say if valves still seal fine, to just go for it. What are your thoughts on that? Leak test didn’t show any leaks. The damage appears on the upper end of the seat. Am I just kidding myself at this point? Is it deplorable to just reassemble with guides as is?

You did a leak down test and it showed no leakage?? How is that possible? A leak down test is done to determine the main leakage point after you have measured a very low compression. So we now have a low compression condition, but with no leaks?

When you say assemble as is, you mean with the broken valve guides, the damaged valve seats, and with the valves hitting the piston? Do you expect the assembled engine to work better than before you took it apart, and the damage to get better over time?

Maybe understanding your long term objective would help here: are you trying to have a fully functional and reliable bike that you can enjoy riding for the next few years? Or a semi-functional bike that you can sell quickly to recoup your costs? Or... something else?

johnkol wrote:

You did a leak down test and it showed no leakage?? How is that possible? A leak down test is done to determine the main leakage point after you have measured a very low compression. So we now have a low compression condition, but with no leaks?

When you say assemble as is, you mean with the broken valve guides, the damaged valve seats, and with the valves hitting the piston? Do you expect the assembled engine to work better than before you took it apart, and the damage to get better over time?

Maybe understanding your long term objective would help here: are you trying to have a fully functional and reliable bike that you can enjoy riding for the next few years? Or a semi-functional bike that you can sell quickly to recoup your costs? Or... something else?

Well I’m not sure it actually had low compression. Someone local said theirs tests at 40PSSI and his bike is fine. I think the piston hitting valves was from previous owner so I wanted to try the different piston approach. I definitely want something to ride maybe not long term though.

Sure, go ahead and put in new piston/rings and let's see what happens.

johnkol wrote:

Sure, go ahead and put in new piston/rings and let's see what happens.

Silver lining… there was a 2008 listed for 3800 with aftermarket exhaust or 3500 stock.  He lowered to 3200, I offered 3000 and he accepted.  All mods except the exhaust.  8000 miles, wow THIS is what these are supposed to look like!? I’m going to use this as a reference while I continue on the other so don’t worry updates will still flow.  I think this was a good deal?

Great condition, street legal, low miles, Brand new tires , chain and sprockets. Wide seat, radiator brace, aluminum skid plate, oversized tank, hand guards, double take mirror, steel braided front brake line, rear luggage rack, plus more. Have FMF powercore slip on… not pictured. 3800obo or 3500 back all stock

This bike looks pristine! Getting it for just $3k is incredible, bikes in this condition around here go for $5k.

Did you get it with the aftermarket exhaust?

johnkol wrote:

This bike looks pristine! Getting it for just $3k is incredible, bikes in this condition around here go for $5k.

Did you get it with the aftermarket exhaust?

Nope, which is totally fair. Was going to add extra for it but he already had plans for a friend. I’m totally ok with it, I want a stock bike for a while. It’s so weird seeing an unmolested WR with the correct bolts and in good condition. My topend should be here Monday and I think this will allow me to really take my time with the rebuild knowing I have a rideable bike and there’s no rush.