my buddie p dick just bought a hmf for his fourmen 450 he sisnt jet it yet and i tried telling him to our else it would be leaned out bad and burn er up will u guys say what u think thanks alot

 

it might poop the bed...again.

 

Tell him to go ahead and write a check for a new engine. He has to jet.

 

Thats what me and pro400ex07 told him, he didnt agree.

 

well if he doesn't rejet then bye bye to the engine and will be sorry he didn't rejet...he will be running a lean mixture and will need to rejet I would get a dynojet jet kit with a needle and jets and get a few different kind just incase he is still too lean or goes too rich and make sure the mixture is as close as possible and you can also check the spark plug after riding it for a while to see wether it is lean or not.

 

I have one of those 475cc Foremans, and I was wondering if I should get a jet kit or not for it. Does it really make much more power than the stock setup? It seems to have plenty enough power for what I use it for. I'm kinda thinking if it isn't broken, don't fix it.

 

You do not rejet if you don't change the exhaust.

 

If you dont know if you need to rejet, just do what you wanted, start it and if its cold use the choke just like you would on any other day, if you dont notice a power gain and the quad stumbles when you pin it and let go right away (like your running and you almost trip but you just barely stay up and it feels really awkard/(not comfortably position) right when you catch yourself from tripping

if your quad stumbles real bad, remove the mod and drive back, and replace the mod and rejet

What does a jet kit do anyway? doesnt it only make it easier to rejet? cuz some people say they see used quads for cheap and they say "ya i wanna get that 400ex it has a jet kit and everything" Does a jet kit by itself offer more power?

 

He better jet it!!!!

 

If you change the air flow through the engine because of a exhaust swap and/or high flow air filter, then you need to change the jets in the carb to keep the correct air/fuel mix. If you dont you can have major problems. The engine can run hotter and possibly melt certain components.