Well I went ahead and had Bubba 297 port my cylinder. I thaught I was going to be down for at least a month. But nope!! 2 weeks. Thats it. Bubba had it for only 2 days and I had it back. It was the shipping that took so long. Ok, for the first impression he was great. Bubba answered all my questions and the work looks real good. I just got it together yesterday. Started it up and it was rough for a bit but once it warmed up, it sounded great! I drove around the yard not getting on it, but even then I noticed it ran better. Untill it is broke in I am only doing short bursts with the throttle. Low end was great before the porting but after the porting, HOLD ON to the handle bars. I thaught when I first bought the TB that getting the wheels up would be a problem, but now the problem is keeping the wheels down! I give BUBBA297 an A+. Before the porting my top speed was between 63-66 mph. Hopefully now I can be a consistant 66mph but I wont know untill break in is done. For those people that doubt a Tb can be fast without alot of money. It can be! I have invested around $700 and it is one quick machine. So when people ask who did my porting I will say BUBBA297 did it. I will advertise on other forums as well as this one. THANKS BUBBA!!! I will keep you informed on the performance.

 

As Elvis would say........ ahhhhh Thank you, Thank you very much.

 

Bubba or anyone,

I did 4 hard runs today and 3 of them topped out at 66mph, 1 of them was 64. And thats without my race silencer,and bolt on K$N. I still dont have full rpm,s

Idle would be around 1200, engagement is at 2400, and when you hit full throttle it will go up to 78-7900rpm,s and go down quickly to 6300 untill full shiftout. What settings should I try on the secondary to get all my rpm,s without loosing top end. The upshift is real quick. What would the 1-1,1-2,2-2 settings do at each setting. The porting you did made a huge difference. It pulls strong all the way through and if I am crusing and hit it wide open it pulls hard also. It is great!

 

There is something not right if it jumps that high then falls down quickly. It shouldn't climb more than a couple hundred rpms above shift out and then fall back down. You actually want a little bit of over-rev on the 250's. Have you rechecked belt deflection yet? I would also like to know exactly what helix and rear spring you have. Also I would like to know what's in the primary for sure. Give me all the clutch specs and let's go from there. The factory rear clutch setting is 2-2. Start there and we might have to go a little lighter if you are running the violet secondary spring. Bubba

 

I have a red/yellow primary and I dont remember what the secndary is. Whatever comes with the agressive kit. I have the stock helix and it is set on 1-2.

 

It will either be the violet or the gold. The 1-2 setting is the second softest setting.

I had a similar type problem once but a little more severe. Mine would take off so hard from a stand still that it would about rip itself out from under you or just flip you over. My RPM's would go through the roof for that initial second then they would drop and the bike would go back to its regular thing. After about killing me numerous times, I took it apart. The problem was that my secondary clutch was slowly beating itself to nothing. The snap ring you remove from the back to separate the cluch was wearing away at the grove. This let the helix back out to far. Enough to get wedged on to the buttons. When the clutches engaged, the secondary stayed stuck in low gear while the engine would rev way up. Then once it had enough pressure, the helix would slip off the buttons and work like it was supposed to.

I don't know if that is your problem but it is atleast something to watch for. Yours still seems like clutch settings or tuning. Mine did start out as something you barely noticed and kept getting worse.

 

I took the secondary apart and it is a gold spring and set on 1-2. Everything else looks perfect.Should I try the stock HPD setting? I have never had it on the setting that they suggest. But the setting they said would be harder with a longer upshift right?1-1 is the softest,1-2 med,and 2-2 hard. Am I right?

 

OK, here's the scale from the stiffest setting to the lightest
2-1 Heaviest
2-2
1-1
2-3
1-2
1-3 Lightest
The first number is the helix position and second is the moveable sheave number. Hope this info will be good for several people.Bubba

 

Now from the lightest to the heaviest what would each position do? Oh bubba did you get my e-mail a few days ago? I also noticed that there is a check valve at the bottom of the carb on the float bowl. Does this go anywhere? There is alot of gas leaking out expecially when I go full throttle. This could be why my gas mileage is so bad. Can I plug this line? I turned the valve upside down and it seems to run alot better on the top end.If it is supposed to connect somewhere, it has been like that since I bought it.

 

That valve is to keep dirt and water out of the float bowl. The only reason gas would be coming out of it would be the float might be a little high, or maybe the needle not closing off real good. The carb bowl is not touching anything on the bottom causing it to do a dance and shaking the needle open is it? Changing the postitions on the secondary clutch will either make it upshift harder and downshift slower, or vice versa. Going heavier tension will make it upshift slower and downshift faster. Bubba