604e Project

[Bunker]

Im about to put a 180 into my CV carb on my high compression 500 motor. Be careful when you buy them, you need to ask for the 7mm slotted heads, not the more common 6mm.

[MT Pocket]

Bear in mind the 604 is NOT cam safe (ref Rotax cam list from club files, Pt No. 237-865)

Or just as safe as leaving your spare keys in the airbox (Sorry Roey, I don't know why that came out!)

[mustaphapint]

Bear in mind the 604 is NOT cam safe (ref Rotax cam list from club files, Pt No. 237-865)

It depends what cam is in it. You're right an 865 fast road cam isn't safe, but most others are. Mine has a 670 which is safe and I think most of us who have fitted the larger engine regard this as a good cam to use.

[woodruff]

I can confirm the 670 cam is safe as long as all other components are standard.

[MT Pocket]

So how do we tell whether our 604s have the safe cam or not, I presume the 670 was fitted later? Is it stamped on the cam itself? I think mine was from a 2001.

[woodruff]

Ady,

If you remove the pulley retaining bolt/washer the number is pressed into the end of the cam, so easy to check (be carefull removing the bolt they can be tight).

[MT Pocket]

Such a wealth of info on here, cheers guys - I'll check at next opportunity.

On the original thread, I couldn't believe how easy the change was to do.
My biggest difficulty was modifying the silencer so it wouldn't be too restrictive yet still be neighbour friendly ish. The end result is part original baffle but mostly perforated tube with soundproofing, a nice sound I think.

[Mr Shiney]

Cheers Craig. Sounds like a plan!

S

my 604 is more or less just sitting and you are more than welcome to come over and spend a couple of hours going over it to help you with the process of doing yours i dont think there are 2 the same when it comes to the 604 /640 variant
and is often the topic of a ruck in my house you dont use it enough Bla Bla Bla

I have seen a lot of posts on carbs and jets but not to many on Dyno results
mine was putting out 70lbs of tourque at the wheel and something like 46 BHP but that is off the top of my head.

it has been set up to run in the 12-14 fuel to air ratio through the range and is returning something in the range of 45mpg this dose go up to 50 when you cruse at 60mph ish
so refuel is about 110mile range

I have a crank case with the top hats still in it so you are welcome to them i will just need to drift them out

I will say if I was to do it all again I would build a 500 version
so if anyone has the cash sitting for a concourse 604 I may well do it
you will also be able to drop your exhaust
Im not back from China until next week i will PM you my number

[digger]

Cheers Craig. Sounds like a plan!

S

my 604 is more or less just sitting and you are more than welcome to come over and spend a couple of hours going over it to help you with the process of doing yours i dont think there are 2 the same when it comes to the 604 /640 variant
and is often the topic of a ruck in my house you dont use it enough Bla Bla Bla

I have seen a lot of posts on carbs and jets but not to many on Dyno results
mine was putting out 70lbs of tourque at the wheel and something like 46 BHP but that is off the top of my head.

it has been set up to run in the 12-14 fuel to air ratio through the range and is returning something in the range of 45mpg this dose go up to 50 when you cruse at 60mph ish
so refuel is about 110mile range

I have a crank case with the top hats still in it so you are welcome to them i will just need to drift them out

I will say if I was to do it all again I would build a 500 version
so if anyone has the cash sitting for a concourse 604 I may well do it
you will also be able to drop your exhaust
Im not back from China until next week i will PM you my number

Craig does that mean what I think it means?
Does Mrs Apophis know