Hello all. I have started my 94 cbr project and I wanted to get you alls suggestion. I have an engine with 2 major cracks in the crankcase, the flywheel side. I wanted to get you all suggestions on what you all think I should do. THIS IS A BUDGET REBUILD

A. Try to Alumiweld the piece back into the engine, or get a professional tig welder to do it. (assumes there arent anymore cracks or damage)
B. Just replace the bottom end of the engine(not sure how difficult it would be to do this, and how costly it would be. I have a california model now, but live in chicago. so I can live without all the extra tubes and such. Assuming the top end for both cali and 49states will work.
C. Replace entire engine...

Looking for the most costly choice.

 

costly as in costs a lot? lol

 

First it's hard to give opinions without some pictures of the cracks.

In general either A or C. B just doesn't really work as case halves should be matched or they require much machining.

If you can find a good tig welder and the cracks are just in the case edges, then A would be a cheap choice, but will require some work. disassemble and reassemble. If the starter idler gear is cracked, that's hard to fix well. Depends on the cracks.

C is a great option if you can find a cheap good used engine. I did this last time. Got a nice engine for cheap and had the bike running again in a day.

 

whoops, I hit submit reply too soon

I had this issue once, but I don't exactly know what went wrong with yours compared to mine so I don't know if my suggestion will work. I f'ed mine up by forcing the starter back into it's place resulting in that inner dowel braking the left side crank case cover (pic 1, 2 & 4 of damaged areas). If it's similar then you can do this. if not then show some pictures of your problem, maybe there's another way around it we can figure out.

At the time, I lived in mexico so YMMV in regards to prices:
I had the guy aluminum weld it inside and out without obstructing that inner pin/dowel that holds one of the gears linking the starter to the alternator's starting clutch. The pin goes into picture 4 and it's not obstructing the pin in picture 3.1. The pin I'm talking about is part number 28102-ME9-000.
The guy was no pro and did a half decent job at welding it back together, so if I had to do it again I'd just do it myself.
Afterwards I took a bolt just a tad too big to fit the inner diameter of the pin, filed it down to the right size, tapped the engine and threaded it in (since there's really nothing on the other side just an empty space beneath the carbs) and 'lock tight'-ed it in place with the red stuff. Picture 5.0, 5.1 & 5.2 show what I'm talking about. It's not a tapping guide and I don't have pictures of that but if there's anything you need to remember it's "go straight", "go slow", "turn & return" aaaaand "lubricate" & you'll be fine.
Guy charged me aprox. 20 USD and I had the bolt, tap and file in my tools so it really only cost a little bit.

 

It just depends on how big and where the cracks are.

Post a picture.

Look on CL or some FB machine shop pages. Guys who can tig on cast could fix that for you and itd be better than alu-weld epoxy

 

Sorry for the late reply. But I have attached the pictures of the cracks. It is on the edge of the crankcase. I have all three parts that would fit into these cracks, not sure how easy it would be for the welder to twist and turn the engine. Was looking for the most cost effective fix. I ordered the bottom end already and considered a full rebuild, but thinking that might not work out so well cause with all the parts I would have to order plus machine work, it would be cheaper to just find something on craigslist or ebay.. So figured i'd try the welder and see what he suggest, but just plan to order a new used engine if i can find one.

 

That should be an easy weld for someone since you've still got the missing pieces and they aren't in a critical area. As long as the side cover surface is flat once done, you should be good.

 

let us know the price of the welder. I, for one am quite curious to know...and to compare

 

Okay, finally got a new engine. Just went ahead and found a F3 engine, going to use the F2 carbs. I was wondering what type of jet kit should I get. Factory or Dynojet. Im running D&D slip on and K&N. And after reading the post on here, how hard is it to get the tuning correct. Is this something I want to tackle on my own or is this best left up to the pros.