swapping out an engine case, change crank seals?

[yophilly]

I just bought an lt80 with a cracked case from a fat guy jumping it. I have a spare bottom end & I'm gonna swap the crank. I know you should always replace the crank seals, But I'm trying to low-buck this one. Has anyone gotten away without changing the seals? How will I know if they're bad when I get it back together? Will it leak oil/gas or run lean?


Thanks, YO

[LT80]

FYI:::::
Seals are only a cpl bucks a piece.
I'd never assemble a motor w/o new ones. Especially for 5 bucks.
Get Suzuki seals. The aftermarket ones are scrap.
You can get the bearings at a bearing shop for about 8 bucks each (not a chinese bearing either). Zuki's are much more.

To answer: yes, it'll suck air, lean out, cost you money.

If you've not switched cranks/bearings before, I'll gladly give advise.

[yophilly]

Originally posted by LT80
FYI:::::
Seals are only a cpl bucks a piece.
I'd never assemble a motor w/o new ones. Especially for 5 bucks.
Get Suzuki seals. The aftermarket ones are scrap.
You can get the bearings at a bearing shop for about 8 bucks each (not a chinese bearing either). Zuki's are much more.

To answer: yes, it'll suck air, lean out, cost you money.

If you've not switched cranks/bearings before, I'll gladly give advise.

[yophilly]

Thanks LT! I was hoping you would chime in! Sorry for the blank reply the first time.......

I'm gonna split the case on the donor motor tonight and really check the bearings etc....

Any tips for splitting the case, issues to look for, tricks for re-assembly would be greatly appreciated.

Do you have a timken/bca #for the bearings?

What king of sealer should I use for re-assembly of the case?

[yophilly]

Well, it definitely needs bearings and seals, no question. The con rod bearing seems good. Should I put some assembly lube on the bearings to prevent dry-start issues?

[LT80]

Sorry for the delay..
New brgs usually have grease in them. Shouldn't need any extra lube.
Get the brgs to go on the crank. I use a fine grit sandpaper and "shine it" till the brgs fit on all the way.
I use heat. I heat the right case side and stick the crank and bearing in it. let cool. Then I heat the left side and stick the right side in it. It should go together w/o binding.
I use honda or yamahahaha grey stuff (I forget the real name) to put the cases together.
Push the seals on till the lip contacts the case. Don't push the lip into the case. I grease the seals.
Hope that helps.

[yophilly]

Thanks, how about the position of the magneto, there's a ton of adjustment in there. I marked it before removal...just put it back where it was?

[LT80]

Yep,
Align the marks. :)

[hawaiianbasshed]

yophilly - lmk how it goes. I got an LT with a cracked case and stripped splines on the crank and will need to do a swap and put the magneto on the different crank LOL... I'm in for more of a treat than you I think... lmk where u get the bearings and such. if you could even pick up a second set at the bearing shop (we don't have any of those here) I'd gladly pay for both our sets shipping priority mail is cheap via flat rate box :D lmk if you'd do that! I'm gonna need a set of bearings as well as seals and gaskets I think I can get everything but the bearings if you're gonna get a set from a bearing shop. I can paypal you money. lmk if u could do that please :D

it's the 96 in my sig... I'm actually hoping to sell my pitbike this week, fix the broken LT and sell it to put money towards a blaster my buddy wants to sell me :D never had a real bike only a few mini's so I'm looking forward to a larger bike to play with.

[yophilly]

Originally posted by hawaiianbasshed
yophilly - lmk how it goes. I got an LT with a cracked case and stripped splines on the crank and will need to do a swap and put the magneto on the different crank LOL... I'm in for more of a treat than you I think... lmk where u get the bearings and such. if you could even pick up a second set at the bearing shop (we don't have any of those here) I'd gladly pay for both our sets shipping priority mail is cheap via flat rate box :D lmk if you'd do that! I'm gonna need a set of bearings as well as seals and gaskets I think I can get everything but the bearings if you're gonna get a set from a bearing shop. I can paypal you money. lmk if u could do that please :D

it's the 96 in my sig... I'm actually hoping to sell my pitbike this week, fix the broken LT and sell it to put money towards a blaster my buddy wants to sell me :D never had a real bike only a few mini's so I'm looking forward to a larger bike to play with.


I'll keep you posted, I'll try to get a list of local-purchase parts and see if I can duplicate them for you. I bought the bearings from a local auto parts store..it took them a couple tries to get it right but they were only $10.00 each in the end. The number was 6204 on the bearing , the number on the invoice was 6204 zzc 3gxl


Yo..............aloha!

[LT80]

money towards a blaster my buddy wants to sell me --> never had a real bike <--

Still won't have one...
And you think you had to wrench on the LT80...
Ahh heck, we all have to learn..:D :D :devil:

[yophilly]

Originally posted by LT80
Sorry for the delay..
New brgs usually have grease in them. Shouldn't need any extra lube.
Get the brgs to go on the crank. I use a fine grit sandpaper and "shine it" till the brgs fit on all the way.
I use heat. I heat the right case side and stick the crank and bearing in it. let cool. Then I heat the left side and stick the right side in it. It should go together w/o binding.
I use honda or yamahahaha grey stuff (I forget the real name) to put the cases together.
Push the seals on till the lip contacts the case. Don't push the lip into the case. I grease the seals.
Hope that helps.

Do you heat the case with a torch? The manual says put it in an oven, but I'll be facing a divorce if I do THAT.....

[LT80]

Oh grow a set and tell the wife this is important...:eek2: :eek2: :devil: :D :D ...j/k HAHAHAHA

You can use charcoal or build a fire and stick it in the coals. I use my wood stove.
;)
It'd be hard to use a torch and I fear that it'll mess up.

[yophilly]

I put the case in front of a propane 'sunflower' heater for about 10 mins, worked like a charm. Thanks for the help, made life alot easier.

BTW, a winderosa 'complete' gasket kit doesn't come with the cylinder base gasket. I used FEL-PRO gasket eliminator, I hope it works.

[hawaiianbasshed]

well, my motor case for LT80#2 came in today... I need to split the case and swap cranks now... does the flywheel need a puller? last motor the clutch came out easy by pulling it. this one is stuck, same for the flywheel... I think after I pull the flywheel and magneto stuff I can unscrew the screws and split the case...

any pix of yours that you did and is it done?

[hawaiianbasshed]

Originally posted by LT80
money towards a blaster my buddy wants to sell me --> never had a real bike <--

Still won't have one...
And you think you had to wrench on the LT80...
Ahh heck, we all have to learn..:D :D :devil:

you know, I decided I want to get me a 250r :D after reading around they're beasts... I found an ATC250r on CL locally for $1,000obo emailed him to see if it's running and if he has a title for it... no reply yet :( this was yesterday....

[yophilly]

Originally posted by hawaiianbasshed
well, my motor case for LT80#2 came in today... I need to split the case and swap cranks now... does the flywheel need a puller? last motor the clutch came out easy by pulling it. this one is stuck, same for the flywheel... I think after I pull the flywheel and magneto stuff I can unscrew the screws and split the case...

any pix of yours that you did and is it done?

No pics, but it's done. Ran great, so well that it's sold already. I used a regular automotive (steering wheel)puller for the flywheel. I didn't need a case splitter for the ones I took apart. I just took out the bolts and gave it a couple light taps with a mallet and the cases came apart. My clutch side fought me a little, but some WD goes a long way. Just make sure you clean it all off before re-assembly.

BTW 250R's DO RIP!!!! Be careful...aloha...