Stock Porting, Results and Questions.

So, my 2hp open transfer port job (transfers and exhaust only at this point) finally got some road time today. After fucking with the jetting and timing I am hitting around mid 40's (not gps'd, but based on the gps speeds of the bikes I was riding with).

However, and I knew this was going to happen I am just looking for other peoples thoughts, my low end is total shit, to put it lightly. I am willing to sacrifice all of my low end when I make the final push to a 50:50.

For those who have ported cylinders and still ride in an actual city (sorry suburbs!) what have you done to retain your stop light forward motion? Lowend pipe? Lower gearing?

I don''t know if this will become a daily driver or anything, but just kicking around ideas.

Iust for some idea of this rat rat awesome bike, haha. Far Left. Champagne Maxi.

Re: Stock Porting, Results and Questions.

Erm, specs..I guess.

Techno Boss

14 Bing (haven't touched my intake ports yet, they kind of scare me! any tips?!)

18x38 (this is why I have some form of lowend, but once I find a 36 it'll be all gone!)

e50 - rebuilt (DMP Stuffed, etc, etc. case matched to cylinder)

2hp (ported exhaust, widened transfers)

Re: Stock Porting, Results and Questions.

compression and a pipe that hits at the same rpm your clutch does that tops out at 50 i would try a dirt bike expansion chamber should get you some more bottom end.

not actual knowledge just read junk

Re: Stock Porting, Results and Questions.

See, the way it's running now (the needle is lean, and the jetting is spot on) the pipe is hitting around 30mph, but I don't feel like the clutch could engage that late.

I could be wrong. It's a 2-Shoe, just tightened springs, and full synthetic ATF.

Re: Stock Porting, Results and Questions.

A 15mm carb or drill yours with a 19/32 drill bit or more radically a 5/8ths. You don't need such high gearing. How do you get on the pipe? You can get the speed through higher RPM. Those high gear sprocket combos do best for a high torque cyl. Assuming you have the all aluminum nikasil cylinder widen the transfers in the cyl and raise them only 1mm. If you put a stone wheel on the dremel and put the tool in the cylinder with the stone perpendicular to the cyl bore you can do it. Raise the exhaust port 1mm and go as wide as possible minding the ring gaps. A 6P Homoet would be better. 16X45 sprockets will get you there. A Simonini pipe is a bit better yet. You will probably be too rich at the bottom if you have the right jetting at the top. You could get a 16 PHBG to remedy that. I f you have the double number cyl it will all be different

Re: Stock Porting, Results and Questions.

Oh yea mill your head to get about 225 compression number

Re: Stock Porting, Results and Questions.

You must be doin' something wrong... I ported a stock 1hp cylinder, and got up to 38mph gps with a stock pipe and 12mm bing. I had decent low end with 16/45 gearing.

Your gearing might be too tall. Actually lowering your gearing will give you better low end, and the top end will be nearly the same. I think your problem is that you are hitting the point where you can't put out any more hp and therefore your bike will only go so fast no matter how tall you gear it. Try 18/45.

Re: Stock Porting, Results and Questions.

) Cupermcnewbster ( /

its in the gearing. Go closer to stock to really see what the cylinder is doing. Its hard to gauge if your porting had much effect because simply gearing out like that with a boss would yield equal results (some speed, but overall meh).

SO yea, go like 14x38 or 13 if you have it to see what it pulls, then start really working the intake, exhaust and transfers to go fast. Also make sure, as noted, you get crazy compression running.

Re: Stock Porting, Results and Questions.

what are the port maps for the #22 cylinder?

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