View Full Version : C.A.S. remote site testing

03-21-2003, 12:47 AM
the College Area Skunkworks team packed up my RS250 race bike sans the front bodywork into the van for remote site testing at an undisclosed location, in an industrial complex remarkably near my "shop". i had disconnected the cables to the power valves and used safety wire to hold the pulleys open.

i found that the "mid range" from 5000~8000 is pretty weak. it's hard to say if it's any worse than normal. but hit 8000 in first gear and the front wheel comes off the ground! HOO-YA. unfortunately, where i was "testing" only allowed a run fully through first gear and a shift into 2nd then it was on the brakes. the CAS team is now investigating a more proper venue for further testing tomorrow night.

at this point, it would seem that locking open the power valves is something to fully consider for racers.

:) chris

micah apriliaforum com
03-21-2003, 09:57 AM
I have been saying that for years because of all the heavy stuff that you can remove once the valves are wired open. I have an RGV set up this way in the shop right now so when I dyno it I will compare results to the RS250 (stock setup) that is also here now.

03-21-2003, 02:04 PM
hey micah, i noticed that there is a cable attached to the PV actuator... do you think the electricals controlling the PV motor also provide control to the oil pump to open ?

my point is this: is it safe to remove the PV actuator assembly as well as all the other shite associated with the PVs?

i'm looking into going to a drag race venue tonight to practice race starts. it is 1/8 mile, so i should get at least two gear changes. i really need to ensure this is not goign to hurt the power before going on with the project... the last thing i need to do is make a modification that could hurt my championship. (i'm currently leading by 3 points)

:) chris

Roswell Rat
03-21-2003, 03:31 PM
Just kill the oil injector and go pre-mix. Just think of the weight savings and you have guaranteed lubrication.

03-21-2003, 04:07 PM
you'll guarantee oiling to the crank bearings? the same ones that are shrouded with seals and have injector passages directly to them? oh, sorry, rules require that the oil injector stays intact.

ok, back to subject... does anyone know how that all works and can provide actual, factual feedback? well, anyway, i'll probably end up really having to figure it out for myself. (only way to do @#%$ anymore, it seems)

:lol: chris

Roswell Rat
03-21-2003, 04:52 PM
Rules? If you are racing some sort of stock class then I would doubt you are able to remove the power valves either. Better quit while you are still ahead. (Points-wise, I mean).


03-22-2003, 02:28 AM
PVs stay in place, else the exhaust would flow into the area behind the PV cover plate. rules specifically say that oil injection must be intact and operational. you're talking about my rules? so you're racing at willow? <img src=http://www.ezboard.com/intl/aenglish/images/emoticons/ohwell.gif ALT=":\">

Roswell Rat
03-22-2003, 09:52 AM
No, thankfully I don't race Willow. Good luck on your project.


03-22-2003, 02:07 PM
thankfully? what do you mean by that?

03-23-2003, 09:09 PM
Hey Chris, sorry to get kinda stupid and basic here, but I want to see if I understand what you did:

You mean you just disconnected the 2 cables on the pulley wheel, and turned the pulley clockwise and wired it in that position (open)?

I saw your post on the cup challenge about testing it in an actual race. Definitely keep us posted, as I'm curious to see if it works and how it performs in actual race conditions.

If it works, I'm assuming that you can then remove the actuator cable from the splitter box, the actuator, and the valve pulleys?

Is that what you mean Micah, you can remove all that stuff?

03-23-2003, 09:58 PM
hi Michael,

yeah, for the drag races, i removed the cables from the PV pulleys and simply safety wired the pulleys in the high speed position. i had to remove the radiator to get to the LHS cylinder. note that safetywiring the pulleys will probably lead to damaging the pulleys, as i'm sure the wire will cut into the metal. i used twisted .035 wire from the cable bracket's center "hole" around to the pulley then back to the "hole".

the real issue with removing the actuator or PV motor or whatever it is called is that there is a cable running from it to the main cable junction box. i suspect that this may be a mechanism for opening the oil pump at high rpm / low throttle opening conditions.

:) chris

03-23-2003, 10:54 PM
OK , easy enough.
I always thought the carbs, and the whole splitting box was controlled by the throttle cable 'pull', but now I'm reading the manual, and it doesn't look like you can remove the (actuator)motor, b/c part of that assembly is controlling the oil pump.

OK I've re-written this post 3 times now, as I read the manual and keep finding out more info...

P. 3-18
<strong>Operation of oil pump</strong>
When the actuator motor pulley turns, the lug (A) on the actuator motor pulley pushes the oil pump pulley groove (B) (the oil pump is operated by the pump pulley when the exhaust valve is over half opening condition).

The splitter box is 1 big pulley with 5 cables connecting to it, however, if I remember correctly, I believe that it's actually 2 separate pulleys side-by-side. I think how it worked is the throttle controlled the right side splitter pulley, with the 2 carbs cables, and the actuator motor/assembly controlled the left side splitter pulley with the oil pump cable.

I'll pull the splitter box top and check it tomorrow.

Of course.. if you do go premix, you CAN ditch it all :)

Stu Jones
03-24-2003, 03:48 AM
Two points -
First is the oil pump is held open at high revs even when the throttle is closed. It is done by the extra pulley and cable you are talking about, when the exhaust valves are open then it holds the oil pump open.
Second point leave the exhaust valves standard you will lose drive with them lockwired open. I mistakenly went out in a practice session with my valves forced open last year on my RGV and it was a dog. Flew at the top end but did not want to come out the slower corners. If you did not need some sort of exhaust valve assembly then the proper race 250s like the RS honda and the TZ Yam would not have them.
Oh and a third point you can safely run premix the bearings do get oiled.

03-24-2003, 01:37 PM
Hi Stu,

i am the one doing this. where i race, the slowest corner is about 65 mph. i am reasonably sure that the revs will never be under 8000 rpm, so i think i can get away with having the PVs locked open, much unlike your situation. anyhow, i am doing this in such a way so that if it doesn't work, i can easily switch back in the pits after the first or second practice session.

:) chris