I called Bill up tonight to check on the status of my cylinder head that he was checking out and talked with him a little bit about the camshaft mod. He informed me that he had a guy with a klx250 put a 300 cylinder/piston in and did the camshaft mod and the same thing happened to him, except the damage wasn't as severe. He told me that the valves were hitting the piston. Main point being, don't do this mod to a aftermarket piston. Bill went as far as saying that this mod shouldn't be done to a stock 250 either. He said that it completely changes the dynamics of the engine and you lose horsepower by doing it.

I'm just conveying the information to you guys. I may have muddled some of what he said just because I'm going by memory, but it was very clear that you should not do this mod. I don't want to discredit marcelinos work and appreciate what he was trying to do.

It should also be noted that I sent Bill the new cylinder head and my cam shafts with the mod done to them.

 

hmmmm....

 

Wow imagine that......

 

It sounds like your speaking on bills behalf. If it were me I would not do that. Does bill know that you are basically quoting what he is saying. I think bill has alot of respect from people here. Maybe he does feel that way but I think I would only post what I'm thinking. If you ask 10 people what they think about the cam mod, you will almost get 10 different answers becasue everybody thinks they know more than the next guy. I don't plan on doing the mod myself, but I do thank marcelinos hard work and trying to come up with something new.

Johoffy22, I'm not going to speak for everybody here, but I'm waiting to see how your project is going to turn out. I hope you get things figured out and can start riding. Keep us posted on what's going on.

 

I told him that I would mention it on the forum. I am the polar opposite of an expert in regards to anything relating to this so I'm not speaking what I think. I'm simply passing on knowledge that I feel could save a lot of people trouble down the road. Everyone is entitled to there own opinions and if they wish can still do this mod.

Would you rather I keep it to myself when it could possibly save someone a lot of money down the road?

He blatantly told me that he disagrees with it. I have a lot of respect for him and his mechanical knowledge so I figured I would just put it out there for everyone. This is not to start a flaming war between members of this forum or to cause anyone to lose any respect for Bill that may disagree. I hope you understand.

I should be back on my bike next week. Bill said the cylinder head was in very good shape and just had a little bit of rust on one of the intake valves. It was also missing a couple shims but aside from that everything is fine.

 

Well, I think you may have mistaken whan I was trying to say, or maybe I didnt' say what I wanted to say correctly. I don't think this is going to start a flaming war between members. I only think that if bill feels this way, why don't he post his own statements. Thats all.

 

I don't see him post too often or else I would have left it alone. I even emailed him a link to the camshaft mod thread.

 

Thanks for passing along the info, I feel that this is very important and if it keeps one person from suffering thru what you are going thru then then it's all good.

 

Marcelino had the dyno run charts for his changes. I remember reading a lot of documentation being done.

His work was done on a stock engine, not a modified one. He was experimenting to gain knowledge and putting forth his results, probably a lot like how Bill got his knowledge. You know, change it up and see what it does. The Marcelino's work was documented for a stock engine and he clearly had a good thought process in doing it. So it seems it isn't a negative on a stock engine.

But as pointed out, when different pistons and other mods come into play the work and documentation from the rider who did the original cam timing modifications is not valid. In other words, what may have worked on the stock 250 may not work on a high comp 250-351. Piston valve pockets may be shallower, although I'd find that hard to believe considering a hotter set of cams would probably have higher lift. But clearly in Jhoffy's case there was a definite problem. It clearly ain't plug and play like the stock set up is.

I've seen this on the KLX650s when things done on the R model are attempted on the C or vice versa. They don't always interchange.

As for Bill vs Marcelino, I've read and seen where hot rodders disagree on things all the time. It's just hard to beat the actual documentation when expressing opinion though. Facts talk... and they seem to tell a different story than the opinion. At least with a stock engine.

 

It is nice to get an update on your progress. But, I think you should have just added this to an existing thread instead of creating a new one. Some one that is searching for more info on the cam mod would not necessarily look in this one. Although I saw the title I opened it only because I knew the Author has had Engine problems and I was curious has to what happed now.