Hello from Ed209-Superbyke RMR200 owner

[forchetto]

Carl and Ed, see my dire warnings and advice on removing the rocker cover on the thread in the link below, post Nº9...(I haven't been called a prophet of doom in another forum for nothing...)
http://www.mychinamoto.com/forums/sh...=3468#post3468

To reply to your post Ed, I have blanked off the air filter hole as it's placed downstream of the filter element and any air and dirt that gets in there goes straight to the engine unfiltered. Just found a suitable bung and fitted it.

After my failure to improve things by dumping the airbox, I did try to run the bike without the airbox lid with no improvement, but I have heard about the compromise solution of drilling the holes in the filter box lid, and in fact have obtained some various sizes of blanking plugs in case I do it and it doesn't work.
So far I haven't had the courage to do so...What size holes did you use?. Do you cover those holes when washing the bike to stop water getting to the filter element?.

Just to give you an idea of how critical airbox design must be with CV carbs, note the photo below. It shows the "snorkel" end of our air intakes. The portion just under the nose of the seat. It has been cut-off by someone seeking to "improve" on the factory's airbox arrangements. Did they not think that the hidden from view, internal "cones" that took a lot of design by a competent airflow engineer and brings with it production and moulding complication, could just have been 3 plain holes?. Why go to all that trouble?. Those cones speed up the air stream as it enters the airbox. CV carbs are critical of not just air quantity, pressure differentials, etc but air velocity as well.

Of course they will say "hey, it runs farking great now, wheelies, blah, blah, blah...", but then again you would say that after hacking (and irreversibly wrecking) that component to pieces and finding their low and mid range torque disappeared, wouldn't they?.



What I have heard is that some tuning shops install a better type of foam filter on similar-engined Suzukis, which have a similar element inside, although their airboxes are a slightly different shape.

The screw you talk about is indeed the mixture adjuster. Mine came 2 1/2 turns out as standard. As it's a CV carb, Turn anticlockwise to richen the mixture. On mine I found that no amount of adjustment made much difference an had to increase the size of the pilot or idle jet from 32.5 to 34. The idle screw is now at 1 1/2 turns out and has plenty of adjustment range.

On CV carbs this idle jet/mixture screw set-up adjusts a far greater range of speeds than just idle. It affects a huge portion of the throttle range. This is why idle jets on CV carbs are so big compared to idle jets on slide carbs.

It's reckoned that the idle circuit affects up to 3/4 throttle, the engine is getting most of its mixture from the pilot jets, not the jet
needle/needle jet combined orifice. Compared to the pilot jets in an older slide valve carburetor, the CV carb has a huge orifice. Whereas a slide valve carb might have a Nº17 pilot jet ( the hole is 0.17 mm in diameter ), a CV carb might have a Nº30 to Nº45 pilot jet. As I've said before our comes with a 32.5 jet.

We all learned to calculate the area of a circle in junior high school. The Nº45 pilot jet has SEVEN times the area as the Nº17 pilot jet.

With a freer-breathing set-up such as yours with an opened airbox and freer exhaust you might have to increase the main jet size by 15% or so. The standrd one on mine is a 1.225. Perhaps take up to a 1.34. Keep an eye on the colour of the plug insulator to see if it runs very white, rather than a greyish-brownish tinge, which would be about right.

From your description it sounds as if you've found TDC on the compression stroke allright. I imagine you have lined up the "T" mark on the magneto rotor with the index mark and felt the compression through the plug hole as you say. I've doing tappet adjustments for years but found this engine particularly awkward. You have to break off bits of the feeler gauges and then bend them into funny shapes to fit in. Even then, tightening the nut causes the setting to go tight and we start all over again...A few days with a bit of a rattle shouldn't damage anything, though.

By a dealer I imagine you mean someone used to working on Suzukis. This engine is identical to a DR200, so they shouldn't have any trouble working on yours.

Hope you find that 3rd gear on your VFR800. It may be only a fault with the selector mechanism, and not anything that has to have the engine split.