well Matt, anything... leaves are gonna be falling soon. better get that bike fixed.

You know one thing Matt's bike and my bike have in common... MHR

Oh no you di int!!! lol   

Well my problem was definitely jetting dropped down to a 400 main second clip position on the needle and for the first time since my rebuild I had power from 3/4 throttle to wide open... Holy **** this bike moves like crazy now!!! I got off and my hands were shaking from the adrenaline!!!

It's all in my build thread except jetting but my setup is 9" k&n with outerwears no airbox 40mm tm38 mikuni (had it bore gauged and MHR didn't bore it all the way to 41.5) v2 reeds 88 small reed top end touch up port job if that, 87.5mm bore rechambered head squish corrected Q v1 pipe. Was running a 42.5 pilot and a 450 main needle clip 1st position. Dropped the main to a 400 and the needle clip to the second position. Now I have to take it out to our property and do some plug chops. Thinking the 400 and 2nd clip position may be a little lean and I'd rather lose a little bit of power to protect my top end.

Now I have to take it out to our property and do some plug chops. Thinking the 400 and 2nd clip position may be a little lean and I'd rather lose a little bit of power to protect my top end.

If you think it's lean on the mid circuit then change the needle.  If not try a 420 main in there without changing the needle. 

I know they say mains only affect 3/4-WFO but I've changed my main and it made a difference from off the pilot all the way to full throttle.  Of course I'm in the 600+ range on a VM44 so I'm not sure if that has something to do with it or not.  But from what I've seen a main change will affect clip tuning as well.

And on your 44 you don't run the UFO slide piece do you? I know it allows a lot smaller jetting and better throttle response from the few people I know that use it.

Sorry I missed this Buckeye, not I don't run a UFO they're crap and don't make a difference.

JH has ran some test on them and the only thing they seem to do is shrink you wallet.

Well....
Brand new slide and brand new needle valve. Still happening. Seems like it cuts out a lot less now though, and it only affect WOT. I'm gonna ride it til the wheels fall off

Hello Deebo.
I have had a similar situation but discovered that when I turned the headlight switch on, my problems went away. If you still have a light mounted and a stock switch, turn it on next time you ride. I would be surprised if we have the same problem but you never know! It is an easy test to try.

Nate

Ride for a couple hours today. It doesn't do it when your wind out 4th and 5th gear. Only 1-3

I still say the main jet is too rich for your set up.  The big question is why is it rich when other guys with a similar engine package use the same or larger jets???

Air filters, pipes and the type of fuel have the largest influence on the main jet size.

Change the pipe and silencer and take it for a test ride.  Mix up some fresh NEW fuel and take it for a test ride.  If it still misfires at the higher RPM in the lower gears lean it down 2 to 3 jet sizes and take it for a quick test ride.  If it has a stock 87 reed valve and petals, it will often misfire at 7600 RPM with some porting schemes and exhaust systems. 

Air filter oil as well as the age of filters especially foam filters can have a major influence on main jet size.  Removing the air filter for a test run is not always a valid test for testing the restriction of the air filter.  I done a lot of flow bench testing and many times an air box/intake system will flow more air with an air filter than without any filter.  I have seen engines run richer on the dyno without a filter than with a filter.  Unfortunately a lot of stuff that happens in an engine does not seem to fit what common sense dictates.

Different silencers can change the back pressure slightly, making the engine need a smaller main jet without affecting the power.

The inside of the stinger and muffler accumulates a very thin layer of carbon as the exhaust system accumulates miles on it.  Over time this layer of carbon WILL AFFECT the exhaust flow and back pressure at the exhaust port.  I have seen exhaust systems with less than 50 hours accumulate enough carbon inside the stinger to cause the engine to act very rich at wide open throttle while driving the engine into detonation with a rich misfire.

One of the most critical welds on the whole exhaust system is at the junction of the stinger and tail cone.  There should not be ANY weld boogers protruding into the flow path where the flow area is at a minimum.  One of the most critical areas of flow is at the junction of the stinger and tail cone.  There should not be any mismatches in diameters as the flow goes from the tail cone to the stinger.  There should not be any sudden changes in direction as the flow goes from the tail cone into the singer.  These are areas that are overlooked and special attention must be given during the manufacturing of an exhaust system.

The above mentioned areas must be inspected and corrected especially if you are having trouble with piston seizures and or holes being burned in the top of your pistons or jetting being very temperamental.  I have seen hundreds of engines with recurring piston overheating problems because the pipe manufacture was sloppy and in a hurry when making/designing/welding this critical junction of the stinger and tail cone. 

Well?

Well....  she's a garage ornament. Haven't rode it since early spring last year.  Time to get to work?  I've got a new aftermarket ladder style swinger to install, just need to get a new chain.  I honestly can't remember how she ran last time out. Must have not been too bad or I would have remembered!

Been running non resistor plugs with the resistor cap.  Thanks for the heads up though...  Sucks what happened to your motor!!  Been there, done that

Matt. What's going on.
HF trip in April you ready. 13 to 17th