moneybags Posted June 1, 2007 Report Share Posted June 1, 2007 Ok, so I am concidering rebuilding my 421 cub since it is down right now. Do you just put new pistions in and go. Or do you have to have the cyclinders replaited every time. Can they be bored out? I did a search but dident find what I was loking for. If they need to be replated, who does it, and how much. $$$ Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted June 1, 2007 Report Share Posted June 1, 2007 Ok, so I am concidering rebuilding my 421 cub since it is down right now. Do you just put new pistions in and go. Or do you have to have the cyclinders replaited every time. Can they be bored out? I did a search but dident find what I was loking for. If they need to be replated, who does it, and how much. $$$ If nothing is broke in the top end, you would be fine with just a hone and new pistons. Nicasil is a pretty hard material and will stand up to some abuse. Might not even need a hone, but its always a good idea when you put a new top end on. - Jared Quote Link to comment Share on other sites More sharing options...
moneybags Posted June 1, 2007 Author Report Share Posted June 1, 2007 Would it be posible to burn the Nicasil off the cylinders walls by running the bike lean or out of gas? I ran my cub out of gas about 3 weeks ago in a drag race (WOT) up sand mountion. Somebody said that it is posible to burn the Nicasil off doing that. I put some more gas in it and if fired up. Cupple days latter after I got home. I checked to compression. Had 185 in both. That has been in the back of my head since it happend. That is why I ask. Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted June 1, 2007 Report Share Posted June 1, 2007 Would it be posible to burn the Nicasil off the cylinders walls by running the bike lean or out of gas? I ran my cub out of gas about 3 weeks ago in a drag race (WOT) up sand mountion. Somebody said that it is posible to burn the Nicasil off doing that. I put some more gas in it and if fired up. Cupple days latter after I got home. I checked to compression. Had 185 in both. That has been in the back of my head since it happend. That is why I ask. If you have 185 in each cylinder, no sense in tearing it down unless something else is broke. Quote Link to comment Share on other sites More sharing options...
moneybags Posted June 1, 2007 Author Report Share Posted June 1, 2007 If you have 185 in each cylinder, no sense in tearing it down unless something else is broke. I believe I have a blown reed floating around in the bottom end. Also my crank is not looking so hot since the RS flywheel problem. You can see a pic of that in the product revew section. I would like to get your input on that one. Quote Link to comment Share on other sites More sharing options...
blowit Posted June 1, 2007 Report Share Posted June 1, 2007 Would it be posible to burn the Nicasil off the cylinders walls by running the bike lean or out of gas? I ran my cub out of gas about 3 weeks ago in a drag race (WOT) up sand mountion. Somebody said that it is posible to burn the Nicasil off doing that. I put some more gas in it and if fired up. Cupple days latter after I got home. I checked to compression. Had 185 in both. That has been in the back of my head since it happend. That is why I ask. Ride it my man. The Nicasil will not melt off the cyilinder but can be beat off by detonation. The melting point of Al is much lower so the piston will melt and transfer to the coating first and lock the motor before the coating melts. Detonation percussion waves will break the coating and flake it off. Brandon Quote Link to comment Share on other sites More sharing options...
dajogejr Posted June 1, 2007 Report Share Posted June 1, 2007 With 185PSI in each cylinder, unless you see obvious signs of cracking or peeling, I don't even think I'd hone it...just let it rip. If anything, hone and rering it....I don't think I'd go that far, though. The reason your ran out of fuel is another issue...though. As in a WOT run and the carbs emptied...or the tank ran out??? I'd focus on fixing that first...Nikasil is about 250ish to get it stripped, cleaned and replated. Quote Link to comment Share on other sites More sharing options...
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