Blue Crank

The area on my crank, left side, directly beside the bottom of the connecting rod, is blue. Do you think its safe to run?

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Yes, As long as there is no up/down play and your side clearance is correct, you should be fine. Many cranks are heated at the factory for assembly. I have 3 brand new cranks, in the boxes on the shelf, that are blued. It's normal.

 

OK. EDIT!!!!!.....

I just looked at your pic and even your stuffers are melted...You are not OK now. Something got a little hot in there.

 

So in any case, if you see bluing on a new crank, THAT would be ok. But yours is needing a new rod kit.

Edited by SAPPERS

BTW, What oil and mixture are you using?

Yes, As long as there is no up/down play and your side clearance is correct, you should be fine. Many cranks are heated at the factory for assembly. I have 3 brand new cranks, in the boxes on the shelf, that are blued. It's normal.

OK. EDIT!!!!!.....

I just looked at your pic and even your stuffers are melted...You are not OK now. Something got a little hot in there.

So in any case, if you see bluing on a new crank, THAT would be ok. But yours is needing a new rod kit.

I bought the bike used and in need of a piston kit. Buddy said he mixed it 32:1 with premium gas but didnt say what type of oil. If i sort out the problem of it getting hot, and keep the running temp normal/regular, do you think it will be fine? I dont race but plan on doing a race or 2 next summer. My dad and uncle say it should be fine, but i have my doubts. I barley have the money to buy a top end kit let alone a new bottom end kit. Plus I dont have the tools to split the cases. I guess I'll have to hope for the best and expect the worst. Just wanted some opinions on it. Thanks :)

 

EDIT: 

Would I be able to get away with a crank and gaskets, and no new bearings? I can afford that but I cant afford $400 for a top and bottom end kit. Thanks :)

Edited by ReturnOfJorddo

Does it have any up and down play? is it an OEM crank and does the lower end bearing on the rod have a full set of bearings and the cage look okay? Do the side thrust washers look okay? Does the crank rotate freely with no rough spots?

 

If you answered yes to all these except the first one(which if good should be a definite NO).... then I would run it for now and save up to do a complete rebuild after you put some time in on it. 

Does it have any up and down play? is it an OEM crank and does the lower end bearing on the rod have a full set of bearings and the cage look okay? Do the side thrust washers look okay? Does the crank rotate freely with no rough spots?

 

If you answered yes to all these except the first one(which if good should be a definite NO).... then I would run it for now and save up to do a complete rebuild after you put some time in on it. 

Up and down play? Nope. Does the crank rotate freely with no rough spots? Yep, feels just like all my other bikes that ran great. The rest, I haven't split the cases yet and taken the crank out. Today I realized that if I wait a month and a half til after my birthday, and don't be impulsive & impatient to put just  atop end kit I'll be able to do a full rebuild. 

You can inspect the thrust washers and the big end rod bearing by rotating it slowly and using a flash light......But.If you have the funds and patients then by all means do a full rebuild. 

You can inspect the thrust washers and the big end rod bearing by rotating it slowly and using a flash light......But.If you have the funds and patients then by all means do a full rebuild. 

I'm going to, and I would take a looksie, but the bike is 20 minutes away at my uncles and he's barley ever home.

If it seems ok. Then I would just run it. From what I understand you're saying, it's just a fun play bike for right now. Besides, if the crank does fail, eventually, there's a 99.9% chance it's not going to be catastrophic. The crank locks and that's it.

Or who knows, it may last 200 more hours. I've seen worse and refuse to break. I say just run a good oil and mixture, have fun and do it all right when the funds are available.

rinse bottom end with diesel, install new piston, go ride. Carefully jet the bike and run 32:1 if you are the main jet often, 40:1 if not. 

rinse bottom end with diesel, install new piston, go ride. Carefully jet the bike and run 32:1 if you are the main jet often, 40:1 if not. 

Thats exactly what I was going to do, along with hone the cylinder. I plan on running it at 32:1.

DON'T hone the cylinder!!! Unless it's not coated.

If it is coated..

Unless you have the proper hone and if you want to clean it up, Just use a Green scratch pad available at your local walmart, dollar general, etc, in 5 packs. Soak it in WD40 and scrub out the bore a little.

DON'T hone the cylinder!!! Unless it's not coated.

If it is coated..

Unless you have the proper hone and if you want to clean it up, Just use a Green scratch pad available at your local walmart, dollar general, etc, in 5 packs. Soak it in WD40 and scrub out the bore a little.

There is a tiny tiny tiny nick in the bottom of one of the ports, dad just wants to eliminate any edges, and the cylinder is really shiny

Use a very fine piece of wet/dry sand paper. Probably 3200 to 4000 grit and smooth out the edges of the nick. If you use something more coarse and get into the plating, it will start to flake off pretty quickly.

Use a very fine piece of wet/dry sand paper. Probably 3200 to 4000 grit and smooth out the edges of the nick. If you use something more coarse and get into the plating, it will start to flake off pretty quickly.

Thanks man! Saved me a trip into the dealer and having to hear them refuse to do it and tell me how it needs to be replated and they can send it away so they can get more money :p

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