90cc w/c porting

[aimo007]

I got a 90cc w/c kit for a a/c drx 90 let a buddy port cylinder minor work done but he did open up exhaust port from about the size of a quater to about the size of a fifty cent piece took out the lip in the port, Now my problem is it seemed to be stronger lower end then it is now I havent done any clutch work yet should I just keep moving forward do the clutch work and try to fix it that way. I never ran the w/c cylinder so I dont know and we only ran the a/c cylinder once so I dont have a good comparison. I had my other sons 50cc, ported, and clutch work done and i dont know if maybe Im comparing it to that anyway will clutch work wake it up looking for holeshot....

[raidernut]

porting on these minis, is best left to the Rich hetricks, Billy holts of the world, the margin of error is too small on these motors.

[bulldogfallon]

That sure is a small list?

CGR :)

[ecmini1]

There is a lot more to porting than opening the exhast.

You can hurt the performance in some cases.

[raidernut]

Originally posted by bulldogfallon
That sure is a small list?

CGR :)

just meant that it is best left to the mini experts

[bulldogfallon]

I was just teasing


Your message is all too right!!

[tireman43]

I would have to agree. Leave it to the experts. There is a big list of people who do good work. Not so big a list for great work though right Gary? :D If your buddy knows port timing and has a wheel to figure everything out then I would go with clutching and see what happens. If he just took a Dremel tool and thought it looked better if it was a bigger opening, which I'm guessing he did, then you may need those experts to help fix the mess. Good luck.

Kevin

[markvette]

sounds like he got the exhaust port to big. opening the exhaust up some will help most of these engines but not too big.

Mark

[wrhracing]

Originally posted by aimo007
I got a 90cc w/c kit for a a/c drx 90 let a buddy port cylinder minor work done but he did open up exhaust port from about the size of a quater to about the size of a fifty cent piece.
Now my problem is it seemed to be stronger lower end then it is now.
I havent done any clutch work yet should I just keep moving forward do the clutch work

Bust out some 4.8 gram roller weights and see what that does for you.
And get some compression in that thing, and it may come alive.

He basically increased the blowdown timing and increased the exhaust duration.
Narrowing the peak horsepower, and moving the power up in the RPM Range.

It should still run however.

[aimo007]

the gentlemen who did my porting isnt a rookie for sure he just never has done a drr 90cc every thing he does is over 500cc and all sleds he reasured me on the work I ve just read so much about drr being so touchy just alittle paranoid about it he said that we were in a differant rpm range and we need to get clutch work done now. Ordered clutch kit from koolkidz hopefully it arrives soon. thanks for info definitly will hear back from me soon thanks again.

[wrhracing]

I visit some of the technical sled forums, tell him i said hello from Billy Holt.

Did he disclose the durations or time areas to you? It doesn't matter.... You'll be happy. If you need any more help I'll be glad to be of assistance.