tromo01

hey guys i can really use some help here, i just recently rebuilt the rear cyl when the cct went out. at the same time i also took out the pair valves( i didnt bolck them off really i just removed the valves and pluged the hose), and added a factory pro +4 advancer, and also added some vacume lines to make the carb syn easier..the problem is now that when i am riding the bike and snap the throtle it will start to sputter and bog down when it hits around 6 grand..so far i know it dose it in 1st and 2nd gear, i havent had enough time to get it up there in any other gear..but if i just sit there and it revs just fine all the way to 9 or whatever it redlines at, the problem is only when i have a load on the engine..any ideas?
thomas

gboezio

There's a lot of varaibles, I'll get hard on it, kill the engine, coast and pull a plug, snap a picture if you can.
Is cam timing right on ?? One tooth off mean headache.

tromo01

as far as i know the timing is correct...had the cams and sprockets aligned exactly as stated in the service manual...

gboezio

Check those plugs then, might be a carburetor setting problem.

JamieDaugherty

Dude, this is your problem - guarantee it. Your rear cams are 180 degress out from where they should be. It's going put-put-put at idle I bet and has tons of bottom end, because it's running like a big single dirtbike. I did the same thing to my bike once, it's so easy to do. I even checked the cam timing TWICE and it looked fine. What you need to do is pull both cam covers and then go back through the Honda manual procedure and I think you'll see the problem.

I'm 99.999% sure this is your problem. I'm leaving 0.001% only because the bike isn't here for me to check!

gboezio

I always wanted to try and turn them 180° (90° fire angle for the hell of it), got to sound funny, but I would not run this WOT.
Having both carbs breathing at once got to mess up the pressure in the airbox big time and cause some headache.

JamieDaugherty

It actually runs great on the bottom end. HUGE torque, lots more than a stock VTR and tons of engine braking too. It's like riding a 1000cc supermoto bike if you can imagine that.

I'm impressed that you mentioned the airbox, that's exactly why it won't rev easily past 6-7000 rpm. Both cylinders are trying to draw from the airbox at the same time which is why it has trouble, basically it's choking out. If you could force more air through the airbox it would be ok, I think.

I ran my bike for two days around Mid-Ohio this way and it was a pain but it made it just fine. I just kept the revs down and railed through the corners at 5000rpm at full throttle and peddled it down the straights. The last couple of years have been a lot nicer with the firing order being correct. Laying darkies out of turn 1 was nice.

tromo01

ok i will check it out as soon as i can, but should i pull BOTH covers, i did replace the front cct but i did it very carefully...but it wont hurt to check it also...as for the low end torque its about the same as it was before..

HondaJim

Too many variables. Reverse the easy stuff first one at a time, starting with the vacuum lines, especially the one to the petcock. Then unplug the PAIR hoses and disable the advancer. See what you've got then.

JamieDaugherty

Yes, checking both cylinders is absolutely critical. You need to have the cams timed to each other and not just to the crank. It shouldn't take you long to see that you are out of whack.

gboezio

Yeah I figured out that the difference of jetting of both carbs was from the odd firing sequence, both intake and exhaust should choke.

JamieDaugherty

Yep, it's the fact that both cylinders are trying to draw from the airbox at the same time (actually, they 'overlap'). This means they are also pushing out the exhaust at the same time too. That contributes, but the airbox is where I think the biggest restriction occurs, at that RPM anyway.