Anyone tried after market camshafts?

10 replies to this topic
  • tk421

Posted September 03, 2002 - 06:17 PM


Hey, before were blessed with the next generation YAMAHA 4 strokes what about after market camshafts for our generation 4 strokes?

Has anyone tried them yet?

[ September 03, 2002, 09:19 PM: Message edited by: tk421 ]

  • Taffy

Posted September 04, 2002 - 03:44 AM


the only ones i heard of were the stroker cams. for two years if not three they were advertised yet nobody could buy any.

they couldn't give any info either. if you're at all interested get yourself a spare set of cams and go get a base grind. anyone who tunes production racers will know what this is.

can't go wrong and worth 1-2 horsepower.


  • MN_Kevin

Posted September 04, 2002 - 04:15 AM


Tell me more about your Adjustable Cams (sprockets).

Theoretically, what would be the benefit?

You purchased them from Florida?

How difficult to set them up properly?

  • SFO

Posted September 04, 2002 - 05:09 AM


Here are a few different cam manufacturers.

Hot Cams... http://www.mxsouth.c...cams/hottoc.htm

Tornadoe cams...

Web cams...

Stroker or white bros repackage web cams.
Web can sell you adj. sprockets as Taffy uses or just go to Falicon.

I have yet to try any of these, I also just adjusted my cam timing via adj sprockets.
Will report back with any news of my tests.

  • Hick

Posted September 04, 2002 - 06:32 AM


SFO, what cam timing did you end up with?

Any hints on where to mount my dial indicator base?


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  • SFO

Posted September 04, 2002 - 07:44 AM


I used 106LCA on the exhaust and 105LCA on the intake.
I used a stud mounted to the head stay engine mount. I also made a curved indicator extension to hook around the cam to reach the bucket.
I used .040 as my base lift or zero for open and closed and I didn't shim the clearance to zero, I was in the middle of the clearance range.

Here is a good cam degreeing link, BTW.

http://www.factorypr...obe center.html

  • Taffy

Posted September 04, 2002 - 09:05 PM


i think the above have said it for me. as for the timing of the cams well i'd rather trust that i wrote it correctly the first time so you need to go into the search and try and find "more ooommmpphh" or something like that.

i really can't remember now. i think i meant to go for 109d on both cams but by the time i tightened the head down it had changed to 107d -i think. if you find it could you provide a link?

yes it was definately worth it! i could feel the difference so to feel it you must gain at least 1 BHP i would have thought. it produces more grunt. you can rollit on in third and just wrench your arms off.

i can't see the point in timing them at 106d BTW but there you go. i always said that RR was a winker. i know more than him any time and i haven't had 6 zillion on a rolling road just to get it half cocked either.


  • tk421

Posted September 04, 2002 - 11:58 AM


Taffy: I know your cam setup works for you, I think it’s probably the best way to go as opposed to just buying new cams.

SFO: Thanks for the links and good luck to you on your cam setup. Let us know how it turns out.

Back in the eighties NASCAR racers were playing around with titanium valve spring retainers, it helped on acceleration and valves from floating.
It would make a nice addition to the YAMAHA.
Posted Image

  • SFO

Posted September 04, 2002 - 01:07 PM


I heard Ty Davis lived next door to Don Ricard the owner of R&D springs.
Every one in the industry that I have talked to loves Ty Davis.
I believe the weight difference of ti retainers vs steel retainers is minimal.That difference creating more hp or throttle reponse is somewhat suspect.
The oem stuff has decent seat pressure and free travel for any cams that are being made today for consumer use.
If I wanted more seat pressure I would run a pre-ti valve spring for another 5lbs on the seat.
The track record of R&D springs is kinda shaky in my experience.
I have seen their springs break on my rfvc motors, f-2 motors, and ex500, not to mention retainer pull through on rotaxes.
I would stick with stock springs and retainers and I believe the hotcam to be the set-up.
They don't require your core, they come with degreeable spockets, and you can buy just an intake or just an exhaust.
Just my 2cents, sorry for running on.

  • tk421

Posted September 04, 2002 - 02:23 PM


Thanks for the heads up on the R & D springs. It surprises me that the titanium retainers would pull through.
Maybe stock springs with the titanium retainers and skip the heavier R & D’s? Just thinking out loud.

Have you tried the Falicon Wheels, or do you use something else?

  • SFO

Posted September 04, 2002 - 04:26 PM


If the taper is machined improperly on the id of the retainer the keepers only contact on a single point instead of the width of the keeper.
This leads to retainer failure.
This was a few years ago I noticed this on a rotax I was working on then I checked my rfvc and it had 2 broken springs and the 3retainers were pulling through.
These are just my experiences and I am just sceptical about their hard parts now.
Not my intention to flame.
Falicon sprockets are pretty much it, don't think you can buy the hotcams sprockets solo.
I think they are 175$ installed.

[ September 04, 2002, 07:29 PM: Message edited by: SFO ]


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