1986 VFR Engine Rebuild or Swap?

Before I ask my question I'd like to preface this with a few things...
1. Yes this was a great bike.
2. Yes I was an idiot and took it for granted and now I'm paying for it.

I have a 1986 Honda Vfr750, RC24, and the bike came to me in great shape, never even dropped once. 24,000 miles, clean title, aftermarket fan and horn. I learned how to ride on this bike, it being my first, and I fell in love with everything about it.

I ran into trouble this past week when the engine started to bog down while riding, so I turned it off after getting to a safe area. The oil light was on, so I changed it(I happened to be in the parking lot of an autozone), and went home. Most notable was that during the oil change, I put in the standard amount (~4.25 U.S. Quarts), after taking out what was in there (~.95 U.S. Quarts). Needless to say, I screwed up big time. But hang on, it doesn't stop there...

On the way home the "bogging" became knocking, so I turned it off and walked it there (some ten miles! :mmph: ) At home I realized I'd put in a synthetic when I was supposed to use SAE :doh: (the weights and viscosities were correct though)

Here's where it stands...

If you where wearing military grade, sound blocking, headphones, you wouldn't notice much difference in the ride. The charging is fine, but the engine will overheat with time. The idle is a little lower requiring the use of the choke. Aside from that, the engine runs the same... sorta...

Without those headphones you'd think you were riding on a jackhammer. I have a 1989 Ford F-150 that makes a tick to let me know when she's a quart low on oil. This is nothing like that. "Knocking" implies vibration and more of a dull "thud" or "clunk", but it's not that. The sound is quite sharp, very loud, and makes me feel like an idiot for even turning the engine on.

I found shavings in the oil when I switched back to SAE(did that the instant I got home).
The clutch lever had been stiffer, but now it's smooth again, I think that's due to it sitting rather than a miracle.
The transmission hasn't missed a single beat in all this and it shifts and stays in gear perfectly.
I never let the engine overheat once, so whatever is happening would have to be due to friction, or something, but not heat.

The symptoms are:
1. Noise(like death)
2. Very Low Idle
3. Overheating over time

My Question: I don't know a lot about bikes, or most cars for that matter, but I make for a pretty decent tinkerer, lol! I have rebuilt a 1989 F-150 to good working order after it was totaled. That included an engine breakdown, three engine swaps, and two transmissions. From what I know about the engines I've worked on, that noise suggests something horrible. But I have NEVER known an engine with serious damage that had so few and otherwise trivial symptoms. If it wasn't for the noise, mostly it's extent, I would never have even guessed engine problems. If you stay on the choke, the bike pulls like always, it's just that folks on the other side of town will call you and ask you to shut all that noise off, lol! The first thing that came to mind was an engine swap, but due to the difficulty of finding one, and the fact that any found have histories I don't know, I've been thinking...

(A)Just how hard is it to rebuild an engine, (B) could this one be worth the trouble, (C) where in the world could I even possibly find a decent rc24 engine?

Personally, I'm leaning towards the rebuild, but does anyone have experience with this sort of work on these engines and have a "woe" to impart, or do I need to just stop being a chicken and break the engine down this weekend?

 

So there was less than 1 quart of oil in the bike? That might have starved the engine for oil. Any time the bike moves or changes direction quickly the oil in the oil pan gets sloshed around. Normally the oil pickup tube is under 4-5 inches of oil so a little sloshing never uncovers it.

With only 1 quart a little sloshing might have allowed the pickup to suck some air briefly. That makes your oil pressure drop to nothing for a second or so. That's really bad on the bearings. Especially considering it may have sucked air dozens of times which adds up.

If the surfaces of several bearings got wore down it might be causing extra friction which would explain the lower idle speed. You can turn the idle speed up with the black knob on the left side by the carbs.

Rebuilding the engine would be well over $1,000. Probably more than the blue book value of the bike. None of the dealers I spoke to could even get bearings for this engine. I did find a source in the UK called David Silver Spares, but I don't know if they have a complete engine set.

My replacement engine was $450 including shipping from Florida. Way way less than a rebuild. Check my thread. Jamie D and Squirrelman both said they knew someone that had an engine.

I personally would think about selling the 24 for parts and using that money to buy the things you need for the 36. That 94 model is pretty cool in my opinion.

(Nothing wrong with synthetic oil, I run my replacement engine on Castrol Full Synthetic motorcycle oil 10w-40 along with Honda Filter)

 

That's what I was afraid of, there being multiple issues. If there can be more than one bearing out, or going out, then a rebuild would have to be for everything. Especially since the margin of error is so slight! I'm with you there, that's not worth it especially since there's replacements out there that cheap! The gasket set alone was ~$150! I'll keep David Silver Spares in mind, but more as a reference I hope to never need, lol!

Yeah, I think the smart thing to do would be to part out the 24, but I just can't bring myself to do it. I call it love. That bike is my first love, too much history(even though it's only been ten months). I'd rather sit it than sell it, lol! The 94 is a fantastic bike, and I can't wait to get it together (oh so close!) but I can't do it at the cost of my old girl. It was my first bike, I learned a lot on it and were it any less of a thing of beauty I'd probably be dead by now, lol. It moved when I needed it, stopped when I needed it, and could lean like nobody's business. I have a deep respect for the bike, it's just a pity I had to lose it before I knew how much I liked it.

If the Lord ever sees fit to Bless me with a replacement engine, you can bet I'll be ten times more careful the next time around! The 36 has one heck of a standard to come up to when I get its fairings and lights, but I'll bet it'll do just fine! The 24 is the one that sold me on these Honda v4s though, I can't just let that go. I know. Pitiful, right. I can already hear the violins, lol!

I didn't know that about the oil though! That's a huge relief, and makes me feel a little less guilty! Almost hopeful, as I start to break the engine down in about an hour or so to inspect the things you mentioned previously. I should be able to tell you and show you exactly what I find by lunchtime.*

I just sent messages to those guys you mentioned! Thanks for the tip! Hopefully they've got something laying around I can use! I can't thank you guys enough! VFRWorld beats yahoo, no contest! Thank you so much for your time and God Bless!
-Corey

Ps. I'll try to get some pics and vids up of the internals too.

 

You cant get a full set of bearings for gen 2 (discontinued years ago) so it kinda takes rebuilding oot of the equation.

 

Sure screwed that pooch ! Keep it under the bench for spares, but find another replacement.

 

Update!
I just found a replacement engine from a bike that was in the back of a truck in an accident. The guy says it was low mileage and runs great, but the plastics and subframe weren't salvageable. I'm willing to take a chance on it, but now I've got another question...

Does anyone know the best way to have it shipped? :noidea:

As a side note, I must admit I feel quite horrible to be SO happy at another man's loss... But I guess if he's selling it then it must not be that important to him, right? Maybe I worry too much...

Well, then I guess this old one's no good... :sad: out:

 

I'll keep it then! Maybe breaking it apart this weekend will allow me to have a good look inside and learn a thing or two about motorcycles! Or confuse me more, lol!

 

Well, so far I'm dealing with shipping costs that are more than the cost of the engine. If I can't find something cheaper then I'll have to call an official TOD, at least for now.

 

How did you let it get to 1qt of oil? Was it leaking or smoking. Sounds like that motor may have had problems before that so i wouldnt be to hard on yourself.

 

Sorry, I'm just now seeing these replys.
Give Estes Express a call. Estes - Homepage They are the ones that shipped my engine from Florida strapped to a mini pallet for about $150.

A mini pallet is like 1/4 the size of a full size pallet. The shipper used lots of wire to hold it into place. Then covered it with a cardboard box and wrapped the whole thing in plastic. Estes Shipping depot is on the North side of town. You would pick it up there. I think home delivery is maybe $30 more, but don't qoute me on that.