[bob]

This is per special request of @bruceb :

In another thread, I wrote about taking my CTX in for service, including fixing the engine not changing to low idle after warm-up. One month later, motorcycle still in the shop and the technician is grasping for answers.

So far

• He replaced stepper motor that controls air into the airbox. Said that it came apart in the box.
• He replaced all valves
• The pressure is down on #2 cylinder. Oil still blowing into airbox [I think that’s what he said.]
• He wondered if I needed new rings. He plans to call Honda Central again on Tues, tho said they are usually busy on Tues.

He estimated I've spent $350 for motor and valves and labor so far.

Other than installing iridium plugs, I have made no modifications on this engine. 49k original miles.

Any suggestions greatly appreciated. I doubt I need an engine rebuild with so few miles and no other symptoms but idle, unless I just got the lemon made that day.

 

[cjm76]

Wow! This is amazing. Was your bike exhibiting any symptoms of poor compression and burning oil before you took it in? I don't have any advice for you because I do not service my bike much either and so have to rely on what the dealer says - but I'm feeling very uncomfortable along with you - and if you could just get it out of there and take it somewhere else for a second opinion you may be miles ahead. I find it hard to believe a Honda engine with your mileage would have these type of problems!

 

[bruceb]

Yeah. No symptoms other than it wouldn't drop out of high idle. Nearest dealer is two hours from here.

Deadly smoke followed by much rain has clouded the past three weeks of riding. But I'll call 'em tomorrow. If I don't get a satisfactory answer, I'll take it back.

 

[Stirling]

What a bummer. I was afflicted with the high idle but it fixed itself so I have no real suggestions. Low compression seems a completely separate issue though, and something I thought was not even in the Honda vocabulary. Making me think twice about the valve clearance check - at 40,000 miles I have not done it yet. If oil is blowing into the airbox on the outside of the air cleaner, it would be the crankcase breather (I assume there is one). First thought in this case is overfilled oil. Dont know how or if compression would affect the breather. If the oil is on the inside of the air cleaner it would be coming up through the throttle body, which would cause poor running for sure. That would be dealership time for me.

Hope it gets figured out soon and you can get back out on the road.

 

[bruceb]

Update
Technician called yesterday [for the first time]. Said he will now check some part of the timing system. He also said that the valves he replaced were not the intake/exhaust valves, but two other valves somewhere somehow. [I was surprised when he told me earlier that the valves only cost $20.] Should know more tomorrow [Sat].

 

[bradntx]

That's weird, throttle valves maybe? I can't see how low compression and high idle could be related but there is so much about this bike that I honestly don't know. I have taken it apart down to pulling the complete airbox off so I could install the cruise control. Other than that it has just been oil filter, coolant, tires and of course some farkle. I'll be flushing all hydraulics this winter.

If you have low compression on one cylinder the should be able to put a bore scope into that cylinder and see what's up.

 

[bruceb]

I get that bore scope every ten years. But then I have more than 50k on me.

I've added my share of farkles over the years. But I don't do anything that would disable the motorcycle. Got no trailer nor courage to work on these computer controlled machines. Been lucky that I discovered both my flats at home, and that they were slow leaks.

Weather's turning nicer. Wanna get out.

 

[bruceb]

Got my motorcycle back after five weeks. Lots of maintenance, including fluids, air filter, front pads, battery, and both tires.

As for the high idle,

1. The mechanic replaced IAC stepper motor and valve housing because the plunger was loose on stepper motor [not the cylinder valves that I thought he meant earlier.]
2. He checked the cam timing and cylinder valves.
3. He inspected engine condition with a leak down test. Found #1 4% #2 10% #3 8% #4 8%. 10% is considered the maximum for an engine with 50k on it. Disappointing tho. #2 also has excessive blow by past rings, oil getting into air box. Low compression plus blowby likely ain't good, I reckon. Has a bad ring to it.

After all that, he did not find improvement in the high idle. Nor did I when I rode it for 70 miles that day. I plan to ride 300 miles tomorrow. If still NG, will take it back with expectation that I don't pay for any more labor.

 

[bruceb]

I just spoke to the mechanic today. They still haven't worked on it. About two months now, in addition to 2.5 months this past summer. Busy with some recalll work. He said he has other motorcycles there even longer, as if that makes me feel better. Needs more mechanics. Sorry, I'm retired.

Last month, mechanic said he planned to replace some kinda boots at the cylinders, not spark plug boots, but of course he has not.

I feel discouraged. Dealer hasn't fixed it after four months. No one else in the area to take it to. Transmission makes such a forceful clunk when I shift into first from a stop that I'm reluctant to ride it.

 

[bruceb]

Finally fixed, I trust. I test rode it about 30 miles.
Mechanic
replaced the IAC stepper motor again, thinking the prior one was defective [part 16430-MJN-A02]
replaced the throttle body rubber mainfolds [part 16451-MJN-A01]
replaced four [spark plug?] insulators [part 16211-MJN-A00]
also some o-rings

Happy days. Now I have my motorcycle to gaze at while I wait for temperature to abandon the freezing mark.

PS for your reference, problem emerged at about 48,000 miles.

 

[fbnewell1]

Glad to see you’re finally able to get on the road - whenever that’ll be.

 

[[email protected]]

Finally fixed, I trust. I test rode it about 30 miles.
Mechanic
replaced the IAC stepper motor again, thinking the prior one was defective [part 16430-MJN-A02]
replaced the throttle body rubber mainfolds [part 16451-MJN-A01]
replaced four [spark plug?] insulators [part 16211-MJN-A00]
also some o-rings

Happy days. Now I have my motorcycle to gaze at while I wait for temperature to abandon the freezing mark.

PS for your reference, problem emerged at about 48,000 miles.

Looking forward to a warm-up enough to ride again!

 

[bruceb]

Looking forward to a warm-up enough to ride again!

Yeah man.