440 questions

[mineralgrey01gt]

i know this is probably a beat question but i didnt see it in the sticky's. Im new to 400ex's. Owned a 250r that i built my self from the frame up and it was a blast, had to part it out because i needed money. I found a 400ex dirt cheap and am looking for maximum power. I know it will never hit the power my 250r had but im not looking for that right now. What is all needed for a 440 kit? I found the complete kit on ebay from L.A.Sleeve for $400 which isnt bad considering what 250r ones are. Now what else is needed besides the kit? Another cdi? Do i need to run a higher octane fuel (ill only run 93 in mine)

[biggun132]

you will need hd head studs from gt thunder, if you dont already have one it is best to run a full exhaust to get the most out of the 440. and depends on what comp you run determines what octane gas to run.

[mineralgrey01gt]

Originally posted by biggun132
you will need hd head studs from gt thunder, if you dont already have one it is best to run a full exhaust to get the most out of the 440. and depends on what comp you run determines what octane gas to run.

the kit im looking at is 12.5/1. I plan on a full HMF exhaust. The guy said the motor has a higher compression piston in it now and when they cranked it it blew the head gasket, i think a valve is stuck myself but thats me. Also said the shifter fork is bent but im going to adjust the clutch and see if that helps any.

[biggun132]

well while your in the head you should go ahead and put kibblewhite valves in. and you will need to go at a min of 93 octane. just better remember to do the head studs if you are going to run that. a 450r carb would make everything go together just nice also.

[mineralgrey01gt]

Originally posted by biggun132
well while your in the head you should go ahead and put kibblewhite valves in. and you will need to go at a min of 93 octane. just better remember to do the head studs if you are going to run that. a 450r carb would make everything go together just nice also.

thanks for the help. Im strongly considering doing this since its not such a bad price.

[sab24711]

best power overall is a port and polish in the head and +1 intake valves. better flow= more power

[mineralgrey01gt]

thanks. I just picked it up today and had it running in about 30 min. It sat up for a while so i changed the plug out and cleaned the carb it runs but backfires and doesnt want to idle without the choke on, needs a little tweaking