Hi

New BB351 owner here and i also bought a Bill Blue modified TM33-34 Mikuni pumper carb.

Only done 30miles so far on the initial break-in. Bike fires right up, and seems to be idling sweet. cos i'm only doing half throttle on the initial 100miles, i've not really noticed a huge difference yet on power. Certainly not lifting the front like i was half hoping in 1st on power alone. Which were some of the initial reports i read about with others making the changeover. But again, it could be just that i've not opened the throttle up enough yet.. I'm showing great patience here. Waiting till 100miles and oil change

Anyway, one thing i am noticing is the bike is noticeably holding back around 5-6k which unfortunately is where most of your gear changing takes place.

If i open the throttle there, it really chugs back. Only done this once or twice mind, as mentioned above, i'm still in the breaking in stage.

Not called Bill yet. Was wondering what any of you carb experts may think ? Lean up top? Not sure what needle i should be meddling with. Not really ever tuned a carb before. But learning !

Oh I'm at sealevel, and have no other mods other than an FMF Q4 end can.. And i did drill the airbox pipe to 1/2" at the airbox, which leads to the crankshaft.

 

Not sure how many of us have the BB351 w BB TM - but not many...

Best to finish the break-in and start conversing with Bill.. He is a fantastic person..

 

Is the lid still on your air box?

I'm not sure but I may be running a 140 main jet, and it definitely lifts the front with throttle only.

 

Hey Oldad, is your BB TM set up well? I would expect your setup to be capable of really big power 6k - 10k - like about 30hp..?

 

Yes, seems sluggish, and i've just come back from a ride (trying to get my 100miles done and dusted) and i ran out of gas around 55miles on the tank... When i was on the 250, i used to get about 85-90mpg out of a tank.

This suprised me a lot, considering i've not given it any full throttle. But i have been doing a lot more accelerating and de-accelerating than usual, as one would expect for a breakin.

I'll give Bill a call... By the time i get home tonight i should have put 70-80miles on her, so as from tomorrow, i'll get some new oil in her and give it some.

 

Yes lid is still on. Bill said to me leave it on, otherwise it'll be very hard to get the jetting right. Also what mileage are you getting from a full tank ?

 

Never have nor likely will have it on a dyno, but it definitely has more horses than my KLX250 had. I rarely ride WOT. Most of my riding is in the woods and that is where I really enjoy the extra torque of the 351. You can chug up the steepest hills without worrying about stalling out, and if you encounter a log, just give it a blip and up and over you go.

Maybe it could be tuned better, but it's good enough for me. No obvious gas odor at the exhaust and the spark plug color looks about right, so it does't seem too rich.

 

I want to think it's about 45 MPG, riding a mix of trail and backroad.

I'd be very interested to hear BB's recommendation. Maybe my tune could better.

 

When considering gas mileage, keep in mind that every time you open the throttle, you're pumping in extra gas, something that doesn't happen with the stock CVK carb.

Ride on
Brewster

 

It outta be a crime to make a 351 suck through the airbox lid..


But if no one knows the proper carb setup for lidless running, your stuck with what is known..