What does this knock sound like to you?

[dingleberry]

Oh ok, my first response then. I thought you meant the bolt out of conrod on my second response. I see no problem with using a rattle gun to undo if you are careful but don't use it on reassembly, make sure you have a good torque wrench. Note: I am not an expert engine builder. 

[akvision95]

So I got a new crankshaft and connecting rods, but the bearings are not the correct color according to the chart in the manual. Can I still use the crank and connecting rods with the incorrectly sized bearings? (a little too big I think.) Otherwise, where can I get new bearings of the correct size? I've looked everywhere and can't find them.

[fret not]

Did you get these parts separately, or as an assembled unit that had been working?  Always if in doubt, and even if you are not in doubt you should use some Plastigage to determine the clearance.

This will be helpful for determining the clearances for the rod bearings but I don't know how you would test the main bearing clearance, as they are not half shells that are held by bolted caps.  Some careful measuring with precision measuring tools is advised.

Rod bearing shells are easy enough to come by but not from a Yamaha dealer.  You will need to use shells made for an automobile.  I forget the specific models but there are at least a few.  A Nissan and a Mazda, but I don't recall the models or years.  There are some discussions on this site about this very subjsct, with the specific information.

[arnie]

Check to make sure the key on the main crank shaft for the valve timing isn't worn . This will make it sound like the engine is about to detonate itself . Mine went and I broke two cams and bent three valves.

[akvision95]

Alright so an update: after much trouble, I've completely reassembled the motor with its new crankshaft and connecting rods. The clearance is within spec but they do have a lot of side to side wobble, so I'm just going to hope for the best. Motor is back on the bike and carbs are cleaned and back together (but not on bike). Seems like I won't be able to get them back on without disconnecting them from each other... Any tips?

I tried to reconnect the clutch lever and noticed that it was stuck so I couldn't connect it even with the clutch adjustment let all the way out. Before I was able to pull the clutch lever by hand to get it to work. Any ideas on this problem?

Also the radiator hose clamps are a real chore to get on.

[Rikugun]

Congratulations on getting the engine apart and back together. Hopefully the crank/rod work will fix the problem.

The carbs should be able to be replaced as a unit from the left side of the bike if I'm not mistaken. How did you get them out or did you remove the engine with them in place?

Regarding the clutch issue -it's unclear if the clutch lever itself is "frozen" or the cable? Also, when the engine was apart, did you have to dismantle the clutch?

[akvision95]

Thanks!

It is the clutch itself, not the cable. I did have to take the clutch off to split the crank case. The clutch lever just won't give an inch which leads me to believe i have to do some sort of clutch adjustment. But yeah it's definitely the lever and not the cable. Cable is fine.

I removed the carbs after I took the engine off if I remember correctly. Messed around trying to get them back in a little bit and it wasn't working. I'll try again tonight.

[cvincer]

Re getting the carbs back in:-


       http://ridersofvision.net/rovforum/index.php?topic=13499.msg122123#msg122123

Personally I split them (& it does not mess up your sync)

[akvision95]

Got everything back in, fixed the clutch (hit it with a soft hammer and then adjusted it), and jumped it.......     

and it turns over fine (except there's a hissing noise from the real cylinder, possibly bent a valve from when I messed up the timing chain and was turning by hand)

but it won't start at all. Not catching or anything, but I can smell gas from the exhaust pipes so it must be kinda working. Before I put it back together I took the carbs apart and emptied them out but didn't do anything extensive other than spraying with carb cleaner.

So any ideas? Probably spark plugs right?

[fret not]

AKV95, how did you determine the clearances were within spec?  A rod can slide side to side on the crank journal but should not tip or rock side to side if the clearances are correct.

Did you get any 'pops' or backfires?  Or did it just crank and wheeze?  Time to check for spark, then which cylinder is firing when.  Is it possible you got coil wires crossed?

Also, time for a compression test to include or exclude a bent valve.

[akvision95]

Used plastigage...  There isn't any up and down play just some side to side, but I guess thats not okay.

Just cranked and wheezed. Anyways, I'm leaving to go back to school in 5 days and I'll be like 4000 miles away so I'm selling it now. Kinda bummed but at this point I feel like I've learned most of what I could have from the bike and its time to move on.

Thanks for all your guys' help and I'm sorry I wasn't able to get it running again. Hopefully the next guy will.