My friends 99 Warrior has a strange klunking in it when you try to start it after it has set for a while or when you choke it. It sounds like someone is hitting the front with a hammer. Once it starts it goes away immediately. Occationally when it stalls (for whatever reason) it will klunk again one time. I have no idea what the noise could be.

maybe the lifters, but im not sure

Mine does something similar ocassionally. I think that it is kick back on the starter. I havent torn it apart to check it out yet though so Im not sure about that. If you find anything post it up here, Im sure that more people have this klunk than just your buddy and I.

Mine does the same thing when I'm cranking the motor over or if it stalls, it sounds to me like it is coming from the starter or flywheel, possibly it is the kick back. I don't know what else it could be.....

I got a 2000 Warrior and it does it some times if it dies while trying to start it.I just figured it was in the starter.Does it occasionally!

I have a friend that has a'97 with the same problem. I also had a Wolverine do the same. Eventually the starter bushings and brushes died on my Wolverine. The dealer told me there was too much strain on the starter because of the 435 kit. Come to find out there just wasn't enough power in the battery. I ordered a harley davidson battery from a sportster and with a little modification to the battery box it has never occurred again and cranks on the first push of the button. If anyone wants the battery stock number from H.D. it is part #65989-97. Expensive but it may solve your problem. (Cutting of both sides of battery box plastic is necessary for installation.) .......Also not a sure fire guarantee.