True Confessions:

I have made it to my destination. The engine is out, the cases are split and like an ancient Mayan priest I have its beating heart in my hand. The rod bearings and main bearings are just nasty. They are all skinned down to the copper and the crank is worn badly in more places then the rod journal. I have a nice used unit from the good folks at eBay.

I still don't know why this all happened. It could be the rod got loose and after that the oil pressure went south causing the mains to wear. I just don't know. I will probably never know. I checked the used crank and rods and one rod shows .004" which is right at the outside of the wear limit. The other rod is .003 which is much better. The looser of the two actually shows a bit of wear but I have no idea how many miles is on this crank. They will get new bearings so the bottom end will be fresh.

I need to check my pistons clearances so I can determine what rings I need and then I can order parts. In the mean time I have a lot of cleanup to do.

 

No problems in the oil pump?

 

I have not opened the oil pump but you can bet it's on my list of things to check. I will also be inspecting every oil passage in the cases and the crank. What is strange about this engine, usually oil starvation shows first in the heads but I see nothing but good up there. I don't think it ran long after the rod started making noise.

 

Probably won't. I've often thought what's happing to the bearings when pulling wheelies and riding it. The oil pump has got to be uncovered and not pumping much if any oil at those angles of 45*-80* that some guys ride at, at times. Plus the bearings are under pressure at that time also. Double bad thing. The only way for cooper to show is low oil pressure.
It sounds like new bottom end time. Have fun and good luck.

 

opcorn:



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Just an update on my VTR project. The tear down is complete. The crank spun the drive side bearing and it cut the case a bit. I decided, if I am into it this far, I will order some good used cases. In fact I ordered two rods, crank, cases and oil pump from the same eBay vendor. I am in essence rebuilding an engine he tore down for sale.

Since these cases are new to me I went through and tested all the tapped holes with the proper sized bolt. Sure enough I found a broken bolt on the clutch cover side. I drilled it out and tapped it for a Helicoil. I flipped the case and started testing on the flywheel side and BINGO! another twisted off bolt. This goes hand in hand with all the goop and sealer I am scraping off. I guess it's way too much trouble to replace a leaking gasket. Just lather it with snot and, of course when that doesn't work just over torque the bolt until it twists off! Freaking ham fisted hammer mechanic!

I used my last M6 Helicoil so I made the trek to the auto parts store and, as luck would have it, they had a M6 Helicoil kit. (Ah! metric bolts finally make it to rural America.) $35 later I had replenished my Helicoil supply but it was actually not needed. I managed to get the second drill started straight and with the help of an Easyout I managed to pull the offending bolt without damage to the threads. I am so lucky I think I will buy a lottery ticket.



At this point I gave the cylinders a light hone to break the glaze. I know it sounds primitive but I took my stripped cases (and I mean bare cases) to the car wash for a right good blast with hot soap and water. I follow up blowing out all the drilled passages with compressed air so I know all traces of water are gone. This is the best way I know to ensure that everything is really clean and at the same time I let the cylinder get a light coating of rust on them. I was taught to build an engine with dry rings and dry rusty cylinders and I see know reason to do otherwise with this build.



So, I had my cases clean, my work table clean and everything ready for assembly. I open my parts bag to find one left rod bearing shell, one right rod bearing shell and a third rod bearing shell that doesn't go to anything. I am also missing three of the four new rod cap bolts I need. I am dead in the water until a new shipment of parts arrives. I did assemble the cases with the crank and the new main bearings. I checked ‘em with Plastiguage and they are well within the wear tolerances. Then I oiled up the bearings and installed the crank to give it a spin and it’s so smooth and silky! It wouldn’t ever turn by hand before. It’s going to be good. I just gotta have patience.



Oh. . .I also sold my 2001 Kawaski Concours. It was a nice bike with good wind protection and real live hard bags but I just couldn't love it. After the VFR it felt like i was driving a truck.

 

Keep us informed. I am not a terribly experienced mechanic myself, although I know that if I twist the head off a bolt I need to get the shaft out and fix it. BUT my older brother is a journeyman mechanic. When I get in over my head, I Skype with him over a project. Looks like you are doing great.






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I had a similar experience about 13 years ago with a Kawasaki ZX-10 that I picked up for $300 Canadian rubles. It had spun the #3 rod bearing but the bearing shells were actually still evident when I tore it down. So I needed some new stuff and the crank needed to be repaired. When I added it up, the cost outweighed the value of the bike so in the end I sold it off to a fella in Wichita who built a drag bike with it. I had some quality shop time and made a couple hundred off it so it was all good.

 

I am not sure I would have gone this far with this bike if I had known the extent of the damage. It will be good when I am done but I will just about break even and that's if I don't count my labor. It's going to be a good bike and I will probably keep it. I have been having fun with is as a puzzle project.

 

I've been enjoying this thread quite a bit. I barely know anything about motorcycle mechanics and repair, so it's been sort of fun watching Merlin perform a magical ritual with a Honda VTR. Hope it all comes together soon!

 

Sometimes it feels like magic. It is a fun project, like a big puzzle except you don't work this one on the coffee table. My dad started me off on the road of motor vehicle repair. His first lesson was "It goes back together just like it came apart." Wise words and the bed rock of all mechanics.

 

I made good use of my Saturday even if it was freezing in the shop. I started the day by putting on many layers of clothing and that made it seem OK. My wife keeps after me to buy a heater for the shop but they all seem like an ignition source to me so I have resisted the temptation to be comfortable.

I knew that today was the big day. I fit the new rode bearings and check the clearance with plastigage. (They are within spec.) I then fit the rods to the pistons and installed the rings, staggered the ring gaps and popped them into their respective holes. I wrapped the big end with a shop towel to keep it from banging into the cylinder wall or anything else. I bolted the big ends to the crank and torqued the one-use-only bolts to 21 foot pounds. I had to disassemble and re-assembe the shift mechanism from the old case to the new one. That done I spread Yamabond (Sorry, no Hondabond on hand) on the sealing surfaces and installed the bottom case. This was my biggest concern, getting the shifting forks to align but I shouldn't have worried. It went back together perfectly. Once I got all the bolts in and everything torqued down I checked the transmission and it shifted through all the gear and the crank can be turned by a strong hand. I used an assembly lube with graphite on all the bearing surfaces. I finished off the day by mounting the brackets that hold the rear suspension linkage on the rear of the now assembled engine. I would keep going but I am tired and I don't want to rush things.

It's getting there.

 

Nice and clean!

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What's is amazing to me that I can clean and clean and still find a nook or hidden edge with more dirt or grime.

 

It turned out to be a nice day (above freezing) and I decided to spend the day in the shop. I installed the heads, timed the cams and got the valve covers on, took a break and then, with the combination of a floor jack and the chain hoist on the pool ladder I managed to get the big lump back in the frame. I got the engine nestled back in it's frame with minimal fuss I only hope to got the torques right on the adjusters and castle nuts. (The VTR has a strange system of threaded adjusters and castle lock nuts.) I am getting there but there is so much more to do.

 

Keep up the good work!

 

It's almost ALIVE!







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It is getting there. That engine is a HUGE lump. It is the bike. Everything else is just support gear hanging off it. I hope it is worth the trouble.

 

I have been pondering the question of why. Why did this VTR engine I am working on have bearing failure? I am leaning toward a low oil event of some kind. I have included the picture below that shows the damage initiated from left to right. Since the rear rod bearing was missing I was not able to examine that but from the shape of the crank throw I would say it was in a poor a shape as the left crank bearing. I am still not able to fully enplane why the cams and cam bearings escaped serious damage. I wish I knew more about the real history of the bike. Even the story I got from the previous owner (that he actually rode the bike) is suspicious to me. There is no way that bike just started to make noise and there is no way he rode it, even for the short distance he said, without it having a cataclysmic failure.



I don't have a picture but there is something worth noting. I purchased a good used crank off ebay (if you noticed in the image above, the original crank pin is gouged and scored) and the new/used crank came with rods and bearings intact. It was interesting to see the normal wear on these rod bearings with instances of slight scoring at the high and low points (points of greatest load) on the crank throw. The seller said the engine had only 19,000 miles. It shows the absolute necessity of good oil pressure and clean oil for engine longevity.

 

Jim you always have to be wary of what any PO tells you, unless you know them personally, it is always a gamble