Have a 2001 warrior. I’ve put 4 new intake manifolds on it over the life of the bike. Haven’t ridden it in two or theee years but when it’s running it runs great. But it backfires every now and then . Sometimes it will be just sitting there idling and will backfire through the carb and blow out the manifold. I’ve adjusted the valves. Some said it was running to lean at idle. I’ve put larger pilot jets in it . Adjusted the air/fuel screw and still having trouble.