[DeeBee]

When I built my motor (~30hp), and since I had been using dual stage reeds, I decided to remove the center support of the cage, since the back Reed goes all the way across, it seemed to just be in the way.
This worked fine for a while with around 140psi cranking compression. A thinner base gasket to bring the transfer duration down, and thinner head gasket yielded 155psi, with .87mm minimum squish clearance. The first time it got somewhat flooded (some fuel run from the Carb to the intake when turning the Carb to rejet) and backfired it absolutely shredded a set of 2 stage boyesen fiber glass reeds.

I wrote it off as a fluke and put a set of 2 stage vitos reeds fiber primary, carbon fiber secondaries ( I was thinking the primary was cf).
Went for a few rides and was careful not to leave the fuel on, as the nedle valve would bleed out fuel causing a little fuel to show up in the overflow hose if left overnight. Had no problems for a couple weeks, until i left it sit out in near freezing weather overnight. When I fired it up it ended up backfiring blowing the carbon petals on the bottom back through the primary Reed.

Quite obviously removing the center support was not a good idea. I ordered a cage of of Ebah and plan to leave the majority of the center support this time around.

Has anyone else had any experience with modifying the stock cage and would care to share their experience, what worked what didn't etc.

i realize there are other options such as vforce, rad valve, 88-96 CR125 cage and spacer, etc. I actually ordered a CR 125 cage and may well install it when I step up to a vm32 from the vm28 I am currently running.



Thanks
db

 

[Larry's Shee]

First thing is fix that carb !! Clean the seat with Q tip & tooth paste, replace float needle if grooved.

As to the reed cage, you may have answered your own question. Look at the CR cage, slightly larger but has two ribs, so .............

When I did the Blaster cage I just followed what I found online.

 

[DeeBee]

Yeah I got the cage (and Carb) taken care of, I went with a second .020" over forged piece ( hand selected for being .0005" larger than average spec) in that cylinder, and after about 8 hours of putting around the house and yard , basically spinning every time I was on the pipe. I finally took her out and same as last first time it hit peak rpm under power it started slapping, when I finally got a good measure myself I realized that my cheap caliper was off by.005" , and the machinist I took it to to measure was telling e cylinder was .005" oversized for a 66.50 bore. Not .005" clearance. So that's how I was getting .007"+ skirt to wall clearance.

Basically starting over, and running everything through port calc., (porting-programs.com)