98 fc600 max potential? problems to watch for?

dale wanted my question posted here

ok lets discuss some of the things i should do if i do go through with the atv drag project with the 98 600fc

replace cranks bearings??

true and weld crank??
(there are some montana hillclimbers spraying on bergs and they are twisting the cranks)

is there a stronger conecting rod than stock. I am looking at going into the cases to weld the crank so if there is a better rod than i should look into it

and that would cover the bottom end from what i can tell

now ignition is there a replacement ignition that guys are retrofiting into the older bergs??

are you guys getting stronger clutchs or clutch springs?

what compression pistons are available for the 600?

head stuff, i will want a preformance cam for top end preformance.

are stock valves good preformers?? are there aftermaret ones for the 600's that dont require new seats. and cam chain is the 98 a good one. i should problay replace it with atleast a new one

I will have it ported for sure.

i need to get this thing making 60hp all motor and then spray 20-30hp on it

do the old fc motors have a lighting coil that i could power my nitrous??

if it is going to be to much trouble i think i will just sell the motor and move on. but if it is something i can do I would love to do it. I have a pasion for 4 strokes and wanted to play with a new motor.

how close are the 650s and 600's in mounting. if i dedicate a chasis to a 8 year old motor and i lose the motor I would like to be able to replace it.

are there other things I am overlooking on the engine for durability or preformance???

thank you very much for your time. if i can get the engine plan done i will start on the chassis stuff which is going to be alot of work.

thanks Dave

PS i know the big stroke motors wont rev but i am looking for 8-9rpm and from the dyno graphs i have seen that doesnt seem to be a problem

replace cranks bearings??

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Insure proper axial main bearing bore alignment, properly fit cylindrical roller bearings as opposed to ball.

true and weld crank??

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Install a new OEM rod kit, true and weld.

is there a stronger conecting rod than stock.

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Yes, however the rod has never proven to be a problem.

ignition is there a replacement ignition that guys are retrofiting into the older bergs??

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The SEM should perform well on race fuel. Go Methanol and / or Nitro and you will need a home brewed total loss system or Mag.

are you guys getting stronger clutchs or clutch springs?

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Several options exist.

what compression pistons are available for the 600?

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97 mm flat top with the deck set to .045"

head stuff, i will want a preformance cam for top end preformance.

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Lineaweaver LRX1

are stock valves good preformers?? are there aftermaret ones for the 600's that dont require new seats. and cam chain is the 98 a good one. i should problay replace it with atleast a new one

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One piece SS 37 Intake / 32.5 Exhaust. Copper Beryllium seats.
Solid roller / solid pin cam chain

i need to get this thing making 60hp all motor and then spray 20-30hp on it

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Done deal providing you are willing to spend the money.

do the old fc motors have a lighting coil that i could power my nitrous?

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Yes.

replace cranks bearings??

Click to expand...

Insure proper axial main bearing bore alignment, properly fit cylindrical roller bearings as opposed to ball.

COST on bearings and can a standard mechanic install or is this more adavanced tooling needed

true and weld crank??

Click to expand...

Install a new OEM rod kit, true and weld.

COST for oem rod kit?

what compression pistons are available for the 600?

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97 mm flat top with the deck set to .045"
And this requires a bore job and sending the cylinder off to be plated??

I was curious on compression #s as i dont want to push them to high to keep it safe for nitrous

are stock valves good preformers?? are there aftermaret ones for the 600's that dont require new seats. and cam chain is the 98 a good one. i should problay replace it with atleast a new one

Click to expand...

One piece SS 37 Intake / 32.5 Exhaust. Copper Beryllium seats.
Solid roller / solid pin cam chain

chain sonds like a good plan

installing thoose valves require the new seats??
valves are around $400ish right what about getting the seats installed?
if that price is high than stock vavles might have to stay in

the only wrenching i dont do on the 450's is the actual porting. I have been into the cases many many times on a yamaha.

if i could keep a budget of $1000-1500 to get the bottom end up to snuff, rebuild it with some preformance parts in the head(porting not included). i could easily justify that on this project.

Allow yourself a minimum budget of $3500.00

Likely plan on spending $4k plus.

Dale

New Rod, New Bearings, New Oem stock piston.

upgrade cam chain and upgrade camshaft

that is the must do's in from what i can tell

bigger valves and seats are optional depending on $$

cant see how that adds up to $4000 but maybe i dont know the swedish math.

if i am seriously going to be $3500 just for the standard upgrades
I guess i would be better off selling it

If you want 60 RWHP as a base you will need big valves, proper camshaft, valve springs and porting.

You will spend $2K on the head alone.

The OEM valves are two piece friction welded items that will not take kindly to Nitrous.

Dale

if i am seriously going to be $3500 just for the standard upgrades
I guess i would be better off selling it

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If you do decide that, and haven't had Bill ship it to you yet, let him know soon. He already has me in line for it.

bill has shipped it already and it will be here thursday

if i decide to let it go i will let you know first

so can you replace the valves with bigger ones without replacing the seats

or even just get stock sized SS valves

porting isnt a big deal for me as I have a sponsor for that

the valves and seats are the expensive part when it comes to the head

so how much on lower end stuff?? bearings and rod and piston.

i will be doing all the wrenching myself just need to get the parts only.