Received wrong engine

[gray horse]

Well, I got my engine about a week ago (supposed to be a 420cc Predator), opened the box and it turned out to be a Predator 346cc instead. Contacted the people and after a few e-mails they said they made a mistake in the ad and that it should have said it was a 346cc not a 420cc. They said I can keep the motor and they will give me a partial refund or I can send the motor back for a full refund. Thinking of keeping the motor and taking the refund, only paid $123.00 for it. Do you think it will be big enough?

Also meant a new neighbor yesterday that races go karts and runs the Predator 6.5. Got to talking with him and he said he would be glad to help me go through the motor and beef it. Said he knows how to rejet the carb to get the best performance out of it. Sounds like it might be the way to go. Any opinions on this motor?

[sho305]

Is that the 11hp? The 420cc is 15/16hp the 390cc is 13hp and there is an 11hp all with the same block. The 5.5/6.5 are a smaller block but similar. Honda never made a GX420, it is a stroked and bored 390.

Some here have used the 13hp 390 and they said it worked pretty well, has more power than stock as it should. One said the 420 was nearly the same as a 390, and it might be similar because a stroker usually only gives you more torque not much hp increase. But it would be hard to tell seat of the pants with no direct comparison. The 390 actually will rev higher with no governor, I think the 420 uses the same head and cam/etc, so it may run out of air sooner. The 420 seem to die out 500 rpm lower.

Most stock carts are about 9.5hp except the newer yamaha 357cc that is 11.4 iirc. So to answer your question it should work as well or better than the stock engine if it is 11hp. Certainly a good deal on the price you got there. It you want more power then get the larger clones, but they don't really go any faster due to having the same gearing.

[gray horse]

Thanks for the advice. I decided to take the refund ($40) and keep the motor. Will be talking to the neighbor and see about beefing this thing up. Buddies want me to put one of my spare HD motors in but I'm not quite ready to do that build yet. Save that for the next build.