LOS ANGELES (AP) _ When Ray Bateman Jr. presents his paper on fighting colon cancer at a clinical research conference next month, he might raise academic eyebrows. Not at his findings, but at his being only 14.

Bateman's co-researcher and next-door neighbor, cancer specialist Dr. Glenn Tisman, said even if the adolescent's voice cracks a little, few will doubt his competence by the end of his presentation.

''Working with him was like working with a (post-doctoral) fellow,'' Tisman said. ''His abilities are remarkable and he was full of knowledge about chemistry even though he hasn't ever taken a chemistry course in school.''

Bateman, a high school freshman and computer whiz, spent more than 1,300 hours researching the project, Tisman said.

''But he's still a kid, basically,'' Tisman added. ''My lab technician used to complain that Ray would leave his candy wrappers laying around.''

Bateman will travel with Tisman to New York City to present their research Oct. 7 at a American Federation of Clinical Research conference. Rules dictate that if two authors submit a paper and one of them is older than 41, the younger author is the presenter. Tisman is 46.

''His being so young will surprise some people,'' Tisman said. ''But I have confidence in him.''

Bateman's father, Ray, said his son's accomplishments don't surprise him.

''When Ray Jr. was 3 years old, the vacuum cleaner broke, and by God, he fixed it,'' said Bateman, a retired civil engineer. ''Age 3. I'd never seen anything like it. ''Now he's a whiz at computers, anything electronic or mechanical. And now medicine.''

Bateman, a ninth-grader at Marina High School in Huntington Harbour in Orange County, said he isn't losing any sleep over the presentation.

''There's still quite a bit of work I have to do before then,'' he said. ''So I'm not really nervous, just thinking about it and preparing.''

Bateman was 13 when Tisman asked him to help research a new method for chemotherapy.

''I knew he had so many astonishing capabilities in electronics and computers, and that he was interested in medicine,'' Tisman said. ''And he was a natural.''

The boy became interested in the subject when he visited Tisman's son Terry, also 14. ''But before long,'' Bateman said, ''whenever I would go over there to see Terry, I'd end up talking to his father a lot more.

''But Terry's understanding, luckily.''

The method Tisman and Bateman developed will need further testing, but Tisman said it has been effective at his private clinic in Whittier.

The new therapy is a twist on existing treatment of colon cancer, Tisman said. It combines two drugs, 5-Fluorodeoxyuridine, or 5-FUdR, and Leucovorin, which kill cancer cells by inhibiting replication of DNA, an essential element in all living matter, Tisman said.

A similar drug, 5-Fluorouracil, or 5-FU, has been used with Leucovorin to treat certain types of cancer since researchers discovered a few years ago that Leucovorin increased 5-FU's effectiveness.

But Tisman and Bateman said their research suggests 5-FUdR may be more effective than 5-FU when used with Leucovorin.

Dr. Youcef Rustum, a noted cancer researcher and deputy director of the Grace Cancer Drug Center at Roswell Park Memorial Institute in Buffalo, called the research an ''important concept in cancer chemotherapy.''

The project has already won Bateman seven awards, including first place in the California Science Fair. The teen-ager is already making plans for college.

''I would prefer to go to Stanford,'' he said. ''And I want to practice hematology and oncology.''

Hematology is the study of blood and its diseases; oncology is the study of tumors.

''I've wanted to be a doctor ever since I was 2 or 3 years old,'' he said.

Bateman, an only child, said most of his free time is spent with his computer. When he was 11 he attended a computer camp at Stanford University aimed at high school seniors. He has $23,000 in computer equipment including a Macintosh II and laser printer in his bedroom, the fifth computer his father has bought him since he was 9.

''He just keeps outgrowing them, I guess,'' his father said.

''I've been very busy with this research so when I do have free time, I spend it at the computer or playing with friends,'' the youth said. ''But I really don't have that much free time, as you can probably guess.''

The elder Bateman said his son assembled the family television from a kit.

''And he builds robots and fixes everything around the house,'' he added. ''It's great. He's a great kid, you know, a remarkable young man.''