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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.

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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.  

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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.

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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.

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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.

 

 

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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.

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3 hours ago, sfdownhill said:

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,

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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.

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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.

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14 hours ago, sfdownhill said:

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.

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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?

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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.

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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.

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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.

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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?

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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...

RC45CylinderNumbering.jpg

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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.

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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?

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

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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,

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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.

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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].

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