Bent rod?

Hello gentlemen and ladies,

I purchased a 2002 VFR on eBay. In the past I have owned a 1998 VFR and a 1994 VFR. I did all the maintenance on the VFR's myself, including fork seals and non-VTEC valve adjustment.

The 2002 VFR in question has 22000 miles on it. The previous owner stated in the ebay posting that the engine had a bent rod. In emails and messaging he described the failure event as a loss of power while cruising on a freeway at normal speed, then the engine began running rough, so he pulled over and stopped. I do not recall if he stopped the engine or it stopped running on its own. After stopping, he was able to start the engine, but it ran very rough and would not keep running. Then it would not start at all. The previous owner was not mechanical, so he had the VFR transported to a mechanic, who checked the engine out and pronounced that it had a bent connecting rod. The previous owner did not ask the mechanic how the bent rod was detected, nor was he able to recall what the mechanic said about a possible cause for a bent rod.

*My question is "How can I confirm or disprove the diagnosis of a bent rod?"

So far, I have drained the engine oil - almost 3 quarts of oil drained from the engine. I did not see any metal particles or gray swirls in the oil. I have not yet removed the oil filter to cut it open for inspection - that is my next step.

Before purchasing a used engine, I thought I'd poke around the bent rod engine and see if it really is damaged internally. A bent rod seems highly unlikely on a VFR with such moderate mileage.

Thank you for any input you can offer.

He has no idea if the rod is bent if he hasn't taken the engine apart to that point.  Avoid this situation is my free advice.  

A compression check would be a fairly easy way of checking the overall health of an engine. I have no idea how one would bend a rod on a stock VFR, that is usually something that happens with forced induction, but if a rod were bent, I would imagine that that cylinder would be down on compression. Also, if a valve were bent or damaged etc, cylinders or rings worn etc, a compression test would pick up on that too. I would not have bought the bike, but if you are stuck with it, that would be my first course of action.

I would turn it by hand as a first step to hear/feel any weirdness.  Second would be compression check as stated above.  Worst case, a used motor can be had for around $300 or so.  Good luck.

P.S.  Bent rod at 22K is highly unlikely.

I appreciate the insights offered.

My plan is to replace the engine with a good used engine, but it occurred to me that, as Bent observed, no one has been inside the existing engine to verify that it has a bent rod.

I will check the inside of the existing oil filter element for metal, then see if it turns over by hand as Rice suggests. If it turns over, I will do a compression check as CandyRedRC46 recommended.

Thanks again for the guidance.

Good plan of attack, cut the oil filter open and stretch out the pleated filter media to look for any foreign material like bearing fragments.

3 hours ago, sfdownhill

I appreciate the insights offered.

My plan is to replace the engine with a good used engine, but it occurred to me that, as Bent observed, no one has been inside the existing engine to verify that it has a bent rod.

I will check the inside of the existing oil filter element for metal, then see if it turns over by hand as Rice suggests. If it turns over, I will do a compression check as CandyRedRC46 recommended.

Thanks again for the guidance.

It seems unlikely, given the "expert diagnosis" of a bent rod, but this doesn't sound like a mechanical failure to me at all.  Mechanical disasters usually involve violent noises and the rapid expulsion of fluids.  A "rough running" and non-starting VFR engine could be caused by, oh, maybe even a charging system problem...  Have you tested the battery?

Ciao,

It would be pretty funny if it came down to a loose ignition coil.

it's the R/R.   LOL.

I'd have to agree - if it was the R/R or a loose ignition coil, that would be pretty funny.

I'll get the oil filter off tomorrow, cut it open with tin snips and inspect. Next put a new filter on and fill it with fresh oil so spinning it won't hurt anything, then test it with the starter. The battery seems solid - it's claimed to be one year old and holds a charge. I've kept it out of the bike and on a tender for the three months I've had the motorcycle. I picked up a compression test kit with a nice long rigid extension so I can get the compression test fitting down those deep plug wells.

I'll search the VFR sites for reg/rect and coil troubleshooting info and keep you all posted. This is the fun part.

I'd probably just pop the valve covers off and take a look too. Make sure the valves are moving up and down, timing chain still has tension, etc.

Thanks wera803 . If I can get it turning, by hand or by starter, I'll follow your suggestion and remove the valve covers to confirm proper activity and belt tension.

14 hours ago, sfdownhill

I'd have to agree - if it was the R/R or a loose ignition coil, that would be pretty funny.

I'll get the oil filter off tomorrow, cut it open with tin snips and inspect. Next put a new filter on and fill it with fresh oil so spinning it won't hurt anything, then test it with the starter. The battery seems solid - it's claimed to be one year old and holds a charge. I've kept it out of the bike and on a tender for the three months I've had the motorcycle. I picked up a compression test kit with a nice long rigid extension so I can get the compression test fitting down those deep plug wells.

I'll search the VFR sites for reg/rect and coil troubleshooting info and keep you all posted. This is the fun part.

If the engine hasn't been ran in a long time, you might want to pull the spark plugs and put a spoon full of fresh oil down each hole, so you dont further damage the cylinders when test cranking the engine over.

Oil down the hole is another quality safeguard - I'll do it.

I searched this site and another for basic R/R diagnosis and troubleshooting, but got mired down in posts about which replacement R/R to use and the benefits of adding additional grounding wires.

Can anybody point me to a thread that outlines the diagnosis and treatment of R/R or coil problems?

In my experience the only time I have seen a bent rod is due to a hydraulic issue, water in the cylinders. Usually rods break and make a huge mess of things.  Regarding the R/R you need to check  voltage output to the battery once you get the engine running.

Do you have the factory service manual yet? Here is the link for a PDF. Run through the given procedures. The manual is not always clear but when you run into a wording problem someone here can typically clarify the procedure.

Thanks for the pdf. I've got the service manual - been reading up on the engine swap, in case it gets to that. I'll look up the electrical troubleshooting.

Oil filter element is clean - no evidence of foreign material. Engine turns over by hand and generates good compression on all four compression strokes.

Question - can anyone confirm that the #4 cylinder is the rear left on my 2002 gen 6? The picture in my service manual  really looks like it's rear left, but #4 could be front right...

More to follow after I drop a little oil down the plug holes, turn it over a few times to clear the oil, then do a compression check. Will the preventative oil down the plug well mess up the compression test readings?

Oil will help and not mess up the compression test... make sure you open the throttle WFO... though highly unlikely a bent rod can be discovered by something simple as a wooden dowel or as precise as dial indicator... either way you can measure the piston's range of travel and note if one comes up short... loss of power can be something simple as the battery for it is the weakest link on our bikes...

Cylinder numbering is as follows...

[image: RC45CylinderNumbering.jpg]

Thanks BusyLittleShop - I've never tried to run the motorcycle yet, just took the word of the PO - silly of me. The battery's been out of the bike on a tender and measures 13.9 volts. I hope beginning by checking that the big spinning pieces of metal are OK will lead me to something smaller that requires less invasive repairs than a bent rod. I actually purchased a complete engine out of a 2007 VFR that was represented as having 7700 miles on it. The seller has 99.9% positive feedback from 77,000 transactions on eBay, so if I need to swap engines, I'm hoping it will do. The detective work on the existing engine has been fun and educational.

Hey Lilshop - I just noticed you have an RC45 in your garage. I think we've talked at Seca and other places. Am I correct to recall your name is Larry? I'm Lance and I have an RC45 with a Two Brothers slip-on and a 17" CBR600 front wheel.

Also - thanks for the cylinder numbering image  - is that from the RC45 service manual? Are you pretty certain a 2002 VFR800 uses the same cylinder numbering as the RC45?

You're welcome...  lets see if it will run.... it may turn out the PO lost is your gain...

Cylinder numbering is the same, according to Haynes.

The RC46 engine was based on the RC45 engine, so it would be unusual if Honda changed the numbering.

Ciao,

Plugs out. Engine turns from the timing hole with socket wrench - it's tight for half a turn then loosens up, I presume the tightness is the four pistons going up, looseness is when they go down.

Existing plugs are NGK Iridium, all look practically new except #4 is blackened. No buildup, but the other three plugs have no discoloration.

Drain plug on and torqued, new oil filter on, 3.1 liters of new oil in. 1/4 ounce of oil down each plug hole. Turned engine through 8 revolutions.

Ready to do compression test.

Looks like fuel problem in #4. This may save me troubleshooting the same problem with the replacement engine - if the replacement engine becomes necessary.

Compression on #3 cylinder is 190psi.

There will be a momentary pause for standard mechanical snafu...I torqued the M10 plug adaptor tightly onto the end of the rigid extension that the compression gauge attaches to. I used a closed end wrench to tighten the plug adaptor. The adaptor still stayed down in the plug hole and the rigid extension unthreaded from the plug adaptor - the plug adaptor must have snugged  down against metal instead of onto its oring. I'm going to go get some fresh red loctite to get the extension bonded to the plug adaptor, let it cure, then pray I'm able to remove the plug adaptor. I can't see using an easy-out if the red loctite fails, there's too much chance of metal shavings from an easy-out dropping into the cylinder.

I saw another compression test kit with a rigid extension that had a rubber cone adaptor instead of a threaded plug insert.

Does anyone know if the rubber cone insert type compression tester fittings provide accurate readings? I'd prefer not to be doing so much praying that the threaded plug insert comes back out with the extension at each cylinder test [If the plug adaptor comes out at all. It would be ironic if a compression test led to removing the head to get the tool out].

How about an extra-long socket? 

[image: S9716KLMAG.jpg]

Good luck!

Ciao,

If you do try it again, maybe put a little oil on the o-ring with hopes it will allow it to slide easier on the metal.

Thanks. I tried the extra long socket, but the plug well has too small a diameter - the 11/16 socket that fits the stuck adaptor is too big to go down the hole. I've cleaned the threads, bought a new fresh tube of loctite red, and applied it. Screwed the parts together and am letting them cure for a few days while I'm out of town for work.

I'll oil the oring for sure next time and be waaaay more gentle when hitting bottom with the compression test fitting.

I've been out of town all week for work but will get back into the garage tomorrow, hopeful that the now-cured red loctite will do its job and help me get the stuck compression test adapter out of the plug hole. It was interesting to learn that heating up cured loctite [To 500-ish degrees F] causes it to release.

Update - red loctite worked - compression test adapter came out easily. Here are the results of the compression test:
#1 - 175 psi
#2 - 175
#3 - 190
#4 - 200

Having pulled the plugs off the shelf, it turns out #2 is the one with the blackened plug - not significant buildup, but discolored black where the other three plugs look new.  It's sooty w dry dusty back material, not oily.

The previous owner said the mechanic he took it to diagnosed #3 as having a bent rod.

I very carefully measured piston travel distance on each cylinder by inserting a slim rod into the plug hole until it touched the piston, marking the rod at bottom dead center and at TDC then using digital calipers to measure the difference. I got these readings:
#1 46.25mm
#2 46.99mm
#3 47.56mm
#4 47.85mm

Next step - fuel system troubleshooting. Find out why the plug in #2 is fouled.
Question - if the problem is ignition - not getting spark, the plug wouldn't foul, would it?

Doesn't sound like a bent rod!  Clogged fuel injector?

Ciao,

Thanks JZH. I'll check the injector and fuel pressure regulator. I'm planning on confirming spark first, just to eliminate ignition - unless guys with more experience [All of y'all] warn me away from spark check.

18 hours ago, sfdownhill

Update - red loctite worked - compression test adapter came out easily. Here are the results of the compression test:
#1 - 175 psi
#2 - 175
#3 - 190
#4 - 200

Having pulled the plugs off the shelf, it turns out #2 is the one with the blackened plug - not significant buildup, but discolored black where the other three plugs look new.  It's sooty w dry dusty back material, not oily.

The previous owner said the mechanic he took it to diagnosed #3 as having a bent rod.

I very carefully measured piston travel distance on each cylinder by inserting a slim rod into the plug hole until it touched the piston, marking the rod at bottom dead center and at TDC then using digital calipers to measure the difference. I got these readings:
#1 46.25mm
#2 46.99mm
#3 47.56mm
#4 47.85mm

Next step - fuel system troubleshooting. Find out why the plug in #2 is fouled.
Question - if the problem is ignition - not getting spark, the plug wouldn't foul, would it?

I don't think you should be checking the difference of TDC and BDC as that will just give you the stroke, and maybe tell you if the crank is bent?

I think you should be comparing all of the BDC lengths and then compare all of the TDC lengths. Then Average the BDC slim rod length and TDC slim rod length for each individual cylinder and then compare each individual cylinder's average length. I would think the largest average TDC/BDC length, if done accurately, could indicate a bent rod, as a bent rod would put the piston slightly lower at TDC and slightly lower at BDC as well, resulting in a larger number for each slim rod length.

Wow CandyredRC46, you are soooo right! I was not using my brain as it was intended - usually I'm OK with  3 dimensional stuff, but your recommendation of comparing the baseline heights of all BDC's to one another, and all TDC's to one another is spot on detective work. This will determine what height the pistons live at and where they start and end their stroke. A bent rod's piston will be lower in its cylinder, both at TDC and BDC. Makes me think of John Cleese when he was with Monty python and exclaimed, "Brilliant!"

I'll gather a round of those measurements today. Thank you.

Yeah me and my coworker were arguing about it for five minutes lol.

:tongue:

I stopped by a few stores [Auto- as well as non-auto stores] to purchase or assemble a precise piston-depth gauge. I was using my fork oil height measuring tool as a template; a slim straight metal tube with a solid collar that can be fixed in place by a threaded setscrew. With a smaller collar than my fork oil tool's that would sit on top of the VFR's valve cover plug opening, the plan was to slide the tube or rod down to the piston at BDC, fix the collar with the setscrew, extract the rod and fixed collar, then use calipers to measure piston depth. Rinse and repeat for TDC. Compare piston depths between cylinders.

Toward the end of my research a helpful Oreilly Autoparts fellow heard me describe a fundamental condition of my project that I had failed to pay attention to: with all sparkplugs out, when I turn the crankshaft with a wrench through the timing port, the engine generates significant friction/resistance at various points around the rotation. My helpful fellow held the opinion that the engine should have even resistance/friction throughout the crankshaft's rotation when it's not making compression. His opinion is that a small four-cylinder engine is built so tightly - thin webbing, crankshaft journal spacing, and tolerances in general - that the very noticeable changes in resistance throughout the crankshaft rotation indicate that some large rotating part or parts are bent inside the cases.

To attempt to identify where in each revolution the resistance increased, I switched from a ratchet to a rigid wrench and began to turn from the bottom - call it 6 o'clock. For two revolutions, the stiction occurred just before 6 and again just before 12 o'clock and lasted 20-30 degrees of rotation at each location. As I continued to turn the wrench without removing it from the timing crankshaft bolt, the sticky spots migrated in a vague clockwise procession [7ish and 1ish, then 8ish and 2ish, etc.]. I couldn't pin the change down to an exact pattern. Since I did the compression test with the battery and starter, I believe the oil pump has already moved some of the new oil into the lubrication system.

Question - does the uneven crankshaft resistance indicate seriously unhappy major rotating/reciprocating components?

Thought 1 - if it's NOT definitely done-bended-real-fersher bad, I'll drain oil, remove clutch and stator, and check the crank turning resistance without those two potential drags on the system. Then proceed with the FPR, injector, and other troubleshooting.

Thought 2 - if it IS done-bended-real-fersher bad, I'll drain oil and coolant, remove engine, and install the replacement engine I purchased before I began to scratch my head about this "bent rod" engine.

After I finished the previous post, I realized the painfully obvious...valve spring resistance.

sfdownhill, 7/2/2016 at 9:45 PM

Hey Lilshop - I just noticed you have an RC45 in your garage. I think we've talked at Seca and other places. Am I correct to recall your name is Larry? I'm Lance and I have an RC45 with a Two Brothers slip-on and a 17" CBR600 front wheel.

Also - thanks for the cylinder numbering image  - is that from the RC45 service manual? Are you pretty certain a 2002 VFR800 uses the same cylinder numbering as the RC45?

Hiya Lance... Larry here... now that you mention it I'm sure we have talked before and I believe Honda numbers all their V4s in the same fashion... may I record your RC45 VIN in my world wide registry???

Hi Larry - how many miles on your RC45 these days?

My VIN is _____________0012 of the US-issued homologation motorcycles. I'll check the paperwork/frame and get the rest of the VIN to you.

Larry - absence makes the head grow softer. My RC45 was VIN JH2RC4507RM000010, so was #10 of the US homologation production run of 50. My friend Hambis Charlambis had #12, but I haven't seen him or that motorcycle for more than 14 years. Do you have San Francisco resident AJ Streak's RC45 in your registry?

**On to the task at hand: I reinstalled the plugs, connected the coils and their connectors, put fresh 91 octane in the tank, took the battery off the tender and installed it. waited for a lightning storm to help bring the creature to life, and cranked it over. The engine tried to catch, but wouldn't. Some combination of cylinders was not firing. I then tested spark at plugs, and #1, #3, and #4 have no spark. #2 [the cylinder whose plug had fuel-fouled black sooty deposits] was firing and valiantly attempting to turn the entire engine. The FI warning indicator did not illuminate or flash.

I am now studying the ignition schematic in section 19-2 of the manual, and it is not immediately apparent where a broken wire or connector could stop spark from reaching cylinders 1, 3, and 4, but deliver to 2. Visual inspection did not reveal any broken connectors or wires, the engine shutoff relay housing was fine, ECU looks good from the outside [Like so many women].

sfdownhill, 7/27/2016 at 11:03 PM

Larry - absence makes the head grow softer. My RC45 was VIN JH2RC4507RM000010, so was #10 of the US homologation production run of 50. My friend Hambis Charlambis had #12, but I haven't seen him or that motorcycle for more than 14 years. Do you have San Francisco resident AJ Streak's RC45 in your registry?

Oh my gosh!!! you have Balls 10 which totaled by Stan Berde on PHC1???

I show balls 12 in Pittsburg Pa owner Jeff Englet

Yes I have A I's balls 51

Mr.RC45 is pushing 60K

In this photo is Stan Berde #10 Me #2 and A I #51

[image: 3RCs3pilots.JPG]

No Larry, I now longer have 'balls 10' [Where does the term 'balls' come from?] I sold the RC45 #10 to Stan, then he wrecked it, I didn't know if you had a record of it. it's frame was badly  broken. I couldn't get any of the mechanic, salvage purchaser, or insurance company sell it to me after it was crashed. Sad.

22 hours ago, sfdownhill

No Larry, I now longer have 'balls 10' [Where does the term 'balls' come from?] I sold the RC45 #10 to Stan, then he wrecked it, I didn't know if you had a record of it. it's frame was badly  broken. I couldn't get any of the mechanic, salvage purchaser, or insurance company sell it to me after it was crashed. Sad.

It's some of my USAF lingo where Zeros are "balls" so 0000010 is balls 10... OK now the picture is complete thanks for pointing that out... I

not only inspected the wreck in person I have photos... Balls 10 was sold by City Cycle Salvage to someone  on the east coast... he sent the

fame to Spondon UK... they welded up broken head stock weld and added the HRC frame kit parts... technically speaking the frame

came out stronger and straighter than new... 

Spondon RC45 HRC Weld On Kit Parts
[image: 521770308_6ce9ba4c2f.jpg]

Broken head stock weld...

[image: Balls10CrackedFrame.JPG]

Larry - thank you so much for the photos - I love all of them. Can you please email me a good quality file of the one with you, Stan and AI? I especially love that one. I'm at hidef@aol.com. You guys look like three kids with their candy. I'm stopping to have lunch w Stan week after next on the way to Seattle on my 2001. 

How did you ever get AI to part with his RC45? He and his wife [Monica?] referred to it as a member of their family.

Whoever they sold #10 to did with it exactly what I had wanted to. Strange that none of the entities involved would consider selling it at the time. I'd better stop blathering on and taking up inappropriate space on this thread.

On to the 'bent rod'. I apologize for the long silence. I reached a satisfactory solution last Thursday, then spent a way-too-large chunk of today learning how to get a brief video of the VFR into a shape and format to post - it's 1:26am and the video is just now ready to attach. I won't  bore anyone with the tedious details of a close encounter of the Microsoft kind. 

I swapped the plugs and coils around among the cylinders with no spark, and the lack of fire stayed with 1,3, and 4. So I moved up into the wiring harness and found a broken wire - the black/white one in the diagram in section 19-2 of the manual. The manual's diagram does not indicate that there is a point in the wiring where a break in a wire would disable 1,3, and 4. I didn't want to get too far into the harness or replace it, so I installed a jumper bypass around the break in the wire. This brought the three miscreant cylinders to life. Actually, I shouldn't disparage the cylinders, as they were standing by and now that they have spark, they run great. See attached video. Note- the video is called 'rightside up' because I held the phone incorrectly when filming.

So I let it idle for 45 minutes to make sure everything remained stable, and it did. Temp stable, fan turned on, FI malfunction indicator and all other warning lights remained off. The beast sounds gnarly-snarly with the airbox open and no mufflers!

As for the plugs, I replaced the fouled plug and one other with the recommended NGK iridium plugs. All four now have the type of tip electrode that threads on and off, but I thought the OEM Honda plugs had built-in, non-threaded tips, don't they?

I also purchased a set of Brisk AOR10LGS plugs but have not installed them. The Brisk units were reported by several VFR owners as producing a noticeable improvement in power delivery. Does anyone have experience with or knowledge of the Brisk plugs?

Thanks to everyone for their assistance and support.

VFR rightside up [2] 07 29 16.mp4

Wow thats AWESOME!

Mechanic led the P.O. astray, thats for sure- -What did you pay for the "salvage" bike on Ebay if you don't mind sharing?  Great deal!

Yes, CZ, this has been a win-win and very satisfying project for me. I purchased the 2002 VFR with a 'bent rod' for $1300.

Awesome job on the other mechanics part in diagnosing a bent rod. :squid:

I learned Motorcycle troubleshooting is a form of problem solving...
It is a logical search for the source of a problem so that it can be
solved... it ain't about jumping to conclusions... it pays to work
methodically...

I sent the photo to your email... I'm grinning because for 2 years I
was a lonely RC45 owner with no other owner to share common
experiences with... that all changed when I found Uncle Stan and his
neighbor A I... next day we rode to Starbucks for morning coffee and a
guy visiting from the UK jumped out the front door with glee
proclaiming "wow 3 RC45's, what is this? a conspiracy?" he would have
been happy to see a single RC45 let alone three at a glance...

I lost track of A I and Uncle Stan... so if you see them please forward their

contact info... I'd love to reestablish our friendship...

Thanks Larry. I'll see Stan a week from Monday and get our contact info to him. Good thoughts on troubleshooting. I've got old-fashioned film-based photos of me on #10 RC45 at Laguna Seca back when I owned her - I'll see if I can dig them up and scan them to send to you.

So true VFR4Lee! I was talking with a friend who observed that the mechanic who diagnosed a bent rod has a bent rod himself...