07 650 upgrades?

Hi, the best mod to do is to port the head and replace the valves with titanium ones with the double springs for better flow and better reving, if you want to increase the compression their is nothing available on the market but you can buy a 450cc piston and machine the top for the right compression...(12,4:1) in my opinion.

Taffy does exchange regrinds so you can save the cam

hard to tell from looking but that liner doesn't look too bad? check it for ovality more than the score

I'd put in dual valve springs oversize valves (kibble whites 36/31 or Taffys lightweight ones 36/32) and port the head.

Ti valves waste of time under 10 000rpm better to save weight at the piston or piston pin.

the older 650s have big valves they seem to work OK with the fcr41 carb but im not really the person to ask yet I have a spare carb to bore to 43mm,

FWIW my 700 is fine with OS valves and the 41, bigger carb will give a boost at the top in theory the bottom and mid should still be fine with the 41. ie it should be better with a bigge carb and even the stock valves so bigger should be better but it works fine at 41

Taffy knows but hes prolly asleap or working on a hangover

Iwis cam chain from.............. Taffy he doesn't put it in the doc because that would be un tafflike but he sells all the good stuff send him a message

that liner kinda looks OK I can't really say from the pic but id be tempted to leave the piston and bottom end alone

head porting by hand takes a long time done right like 8 hours or so

cheapest fastest good way out is X-1 or X2 Taff exchange regrind of your cam, IWIS camchain kibblewhite stock size 35mm intakes and Dual valve spring kit.

cheapest performance mods match port the intake boot/head and hog out the exhaust tract a little, unshroud teh valves in the head, if you have the stock exhaust tidy up the collector 2 into one join in the exhaust and grind out the welds from the inside of the headers and open up the muffler.

the X-2 grind with the stock head brings everything down about 1000rpm peak power is down 3 hp or so, off idle tourque is increased peak tourque similar but the delivery is so much smoother its a very nice cam. I havent't tried an X-1 again talk to taffy

OEM piston is ELKO/mahle and very light, 270 -280gm, oem liner is very good also but they are a bit pricey, liner can be recoed

hello

can't agree with Johnny either. yes if you have a 450 you might go to Ti but for the 650 it's money wasted.

Damon is right and I'd just make the point that there might be a peak drop in HP of 3HP which I think is doubtful but for sure if you rocker the power down you lose 'some' top end. boy does the torque cam pull and it's smooth and quiet.

the top end cam keeps the same mid range with a whack at the top. you need to be flat on the tank and using the gearbox in a hurry otherwise it's the same bike. 2 different bikes in one!

I wouldn't worry too much about bigger valves. just port the head and work on the exhaust ports and the inlet rubber to inway to the head. the CSA here is at it's poorest.

get a good IWIS cam chain, a torque cam, do a little bit of porting, get the valve seats all cut nice, get a jetting kit and you'll be on a totally different bike.

BTW, Johnnie - I DO make a HC 650 piston and there is absolutely no way that there should be any dome on the 650 let alone be flat. My HC pistons have slightly less dish.

regards

Taffy

That is bad luck Shorty you wont forget to tighten next time.

You can check if your valves are ok if you haven't taken them out yet by pouring a little petrol, kero, turps or something similar down each port and observe if it leaks out past the valve into the combustion chamber. They probably will be bent if they have hit the piston.
Don`t worry about titanium valves if you are on a budget. Probably a waste on the 650 anyway.
You can just replace the bent ones with OME.

OR if you wont to go larger, and are not afraid of some work...Might just as well put bigger ones in if you HAVE to buy new ones.

I made my own oversized valves from ferrea wrx superflow shortened and regroved but that takes some machining.
Taffy may know if there are some oversized ones available off the shelf.

BUT with bigger valves you will need seats cut, this guy here in OZ did mine, installed new seats, valve guides (The valve guides in mine were quite worn at 100hrs) he has a program for it. Watch video. Only way to have it done in my opinion.

http://www.octanealley.com.au/workshop- ... achine.php

... And then with some porting, and blending, but do NOT remove anymore material than is necessary on the short turn radius (keep the radius large and smooth as possible) orthe port floor other than to make them smooth. You can open up the bowl and trim around the guide... IF you are good with grinders, DON`T slip . I grind plastic moulds
for a living.

Match port to rubber manifold as best as you can, it is sort of odd.

Match exhaust port to pipes.

Get a LX1 or Lx2 exchange cam from Taffy.

Double valve spring set, mine came with titanium retainers.

New cam chain DID is fine for 100hrs in my opinion.

Clean top of piston and bore thoroughly.

I would not touch the bottom end should be fine.

Good luck,

spanner

Might want to replace your rollers on the cam followers, KTM ones fit.

Cheers spanner

Hi Taffy i know about the hc pistons you sell, but what about the compression ratio??? I want to increase the compression to 12,4-5:1 .I have replace my valves with bigger ones(titanium 37/32 from xceldyne) and port the head, i think hc piston is the only way to improve the torgue, am i wrong?

I thought Ti Valves wore out the seats faster, No? I know the motocross magazines complain about Ti valves when a Manufacture puts them in a bike because if your not a Factory racer, your spending a lot of money sooner (Ti) because they wear faster.

standard compression ratio is 13.8 to 1 so what are you on about Johnny boy ?????????????????????????????????????????????
??????????????????????????????????????????????????????????????????????????????????????????????????????????????????

regards

Taffy

i was talking about my '04 650cc motor, the standard compression (elko piston) is 11.8 to 1 or not?

80mm crank with the 100mm elko CR was 11.4:1 with the OEM headgasket.

an earlier closing cam like the X2 puts the effective (dynamic) CR up but only a tad. works out about 0.1:1 per degree on the 700.

http://www.wallaceracing.com/dynamic-cr.php

What the hell
This scares me...i just bought new 08 650 and i hope they last longer than 4000km...
Did you drive it hard ? :?

If you read the link Shorty posted it seems a rocker adjustment locknut was left loose and come undone, getting eaten by the cam and breaking the camchain.
I have 170hrs/8140km on my bike with just normal maintenance. Don't be too worried.