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Cheetah Cubs?


RNBRAD

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Yea there are several porters out there porting these plated cylinders and have ported plated cylinders for years with no problem. I'm hearing their is some horsepower to gain with porting but minimal, something like 6 to 7 ponies, of course nothing like the gain from stock cylinders. I need to contact Dan at patriot and see how soon he can get some to me. I always hate sending stuff out somewhere after it has been polished, that should be the last step. Fireman, you have a number for Nate? If so PM it to me. Thanks. I'm also debating a 7mil, :shrugani: but man those cranks are high, about a grand. :cry:

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theres some interesting info on planet sand on this matter, porting a Nikasil jug is kind of iffy ,you have to use carbidew/ a good lubricant and be very careful not to flake around the edges,it can be done. the big names who sell these are wholesalers and will port them before they are plated i n alot of cases for fear of nickle coming off, a 6-8 hp gain is possible on the cubs. the transfers areset in the low 130's and the ex timing comes in around 194-196 on most cub monos from what ive heard. Most dune ported bikes(drag shes) have alot higher timing than that. :bolt:

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Brad your inbox is full.

And loco wheres the super wallpaper pic of her on that nice red thing.

401802[/snapback]

 

Sure was, try again. :cheers: Those things need a warning buzzer or something when they get full. :D

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I just got a bare 7 mill cub last week and the porting is very close to where I would like it. I'm suprised if people charge more than 3-400 as there's not much to do. 196 exhaust would be getting too much on some of the smaller cub motors, IMO. As for porting, I would have it done before the plating. I have done porting on pre-plated cylinders (snowmobiles) with diamond tipped cutters with sucess, but everyone always worries about the flaking. I wouldn't guarantee porting on a pre-plated cylinder either.

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Maybe I'm missing something here but I've seen countless plated cyl's ported on MX bikes without a second thought about the plating flaking off. I've never seen it happen and I've peeked inside more than my share of cylinders. Do the cubs have some sort of Nikasil plating that no one else uses or what? I'm under the assumption that Nikasil is Nikasil, no differences between what Yamaha uses on YZ250 and what is being used on cubs.

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Porting plated cylinders is huge in the motorcyle world. Big named companys like FMF, procircut, RPM, Hickman, White Bros., Forward motion, ect., ect., you will never see them replating a cylinder after porting. I don't see what the big deal is?

 

Someone, please shine some light on this subject.

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If you port first, then plate, the plating wraps around the port chamfers and in to the transfer tunnels, etc. If you port after the plating process, the port chamfers are no longer plated and the nikasil becomes exposed on a sharp edge. The sharp edge allows for an area where a piston ring can start to chip away at the nikasil. Again, I've never had an issue either, but have heard of certain Kawi's having this issue, especially when the nikasil is a tad thin on certain sides of the bore (exhaust side w/larger ports promotes shorter plating life). Hope this helps.

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so does your wife!  hmm3grin2orange.gif

401873[/snapback]

OH CHRIST

I just spit coffee on myself....

 

ARE CUBS PORT FRIENDLY?

 

and a grand for a 7mil crank? Holy shit. Those things must really work! Is that 7 mil all at once (move the pin 7 mill), or 3.5 mil (move the pin 3.5 mil) for a total of 7mil swing?

 

I need to get into the 7mil crank building business. :huh:

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Yeah, you should start building cranks, cause everybody else is rippin poeple off. How can a crank that uses all of the exact same parts as a stock crank, only difference being the pin holes in crank webs located differently, cost $500 more than a stock crank?

 

I would really like to know!

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In response to machwon...I don't know if they've switched to Nikasil, but Kawi's used to use a plating called Electrofusion. This type of plating was prone to flaking off and not only at the edges of the ports. If you encountered any type of detonation the plating would start removing itself frome the top edge of the bore.

 

Let the good times roll!

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