Yamaha TRX850 Enthusiasts Forum

Can´t find it, is the standard cams 105/109 as the kent cams??

Don't have the figures to hand but I know my Kent cams have different duration to standard.................

dandywarhol wrote:Don't have the figures to hand but I know my Kent cams have different duration to standard.................

Yeah but lobecenters should be same as you use same sprockets right!?

it was my understanding that all they did was grind some off the base of the lobe ,, so you need a bigger shim and you get more lift ,, but i cant see how the timing would change

Yeah, but if you grind off the base and fit a different shim the valve will open earlier/close later........................

dandywarhol wrote:Yeah, but if you grind off the base and fit a different shim the valve will open earlier/close later........................

Yeah duration is longer on the kent´s

Does this mean that I can have the standard camshafts reground to become a performance enhancig set of cams ? And in changing shims I would still be aiming for gaps recomended in workshop manual.

trxster wrote:Does this mean that I can have the standard camshafts reground to become a performance enhancig set of cams ? And in changing shims I would still be aiming for gaps recomended in workshop manual.

That´s the way it´s done by kentcams, tornado, megacycle....where kentcams is the only one´s you can just put in without slotted sprockets...
...wich explains my poor top power results, slotted sprockets going in....

Ok - I don't know what you mean by 105/109 killer

Cam timing, as I know it, is - degrees of inlet open before TDC/inlet closing after BDC and exhaust open deg. before BDC/exhaust close after TDC.

That' s 4 sets of figures. There will be a corrolation between your figures and my "old school" technology - I just can't work it out.........................

Any cam thats been reprofiled will benefit from having the sprockets slotted to enable the individual timing to be set accurately - especcially if the head/barrels have been skimmed.

My reprofiled Kents are on slotted sprox

dandywarhol wrote:Ok - I don't know what you mean by 105/109 killer

Cam timing, as I know it, is - degrees of inlet open before TDC/inlet closing after BDC and exhaust open deg. before BDC/exhaust close after TDC.

That' s 4 sets of figures. There will be a corrolation between your figures and my "old school" technology - I just can't work it out.........................

Any cam thats been reprofiled will benefit from having the sprockets slotted to enable the individual timing to be set accurately - especcially if the head/barrels have been skimmed.

My reprofiled Kents are on slotted sprox

105 & 109 is the degrees of lobecenters, inlet and exhaust. Inlet is at center on valve at 105 degrees and ....yeah you get it....

Meaning the inlet valve is fully open at 105 deg. past top dead centre and the exhaust fully open at 109 after BDC?

dandywarhol wrote:Meaning the inlet valve is fully open at 105 deg. past top dead centre and the exhaust fully open at 109 after BDC?

I don´t know all the tdc bds ot at and dt.....but yeah....
All it means i have to get my cams + 0,5 degress on inlet and - 2,6 degrees on exhaust....
...any feeling on what that is on mm???

Hello I'm Italian and a new friend of the forum. I am writing to ask if you can improve the performance of my TRX 850 of 1997 changing the camshaft, if what is on the increase in performance (in HP) and if possible I need some web address, to make an estimate of expenditure for the purchase. Greetings to all members of the forum and thanks to everyone for the help.

amiciangelo wrote:Hello I'm Italian and a new friend of the forum. I am writing to ask if you can improve the performance of my TRX 850 of 1997 changing the camshaft, if what is on the increase in performance (in HP) and if possible I need some web address, to make an estimate of expenditure for the purchase. Greetings to all members of the forum and thanks to everyone for the help.

You can have your camsprockets slotted for other timing but you only will be changing where you have your top power. Greater overlap is more top power and less overlap is more tourque.....and less top...

Thanks, I think I understand, but I wanted to know who sells the camshaft and if you should mount them, also because I think that changing the timing of the originals, the power gain is relative.