Mods complete! - - One problem though

Hey,
I have completed my modifications to my 82 750 Maxim. This is what I have done:

1. K&N Pod Filters
2. Vented Crankcase vent to each Filter
3. MAC 4-1 Exhaust
4. DynoJet Kit---Used Largest Main Jet===DJ136. DynoJet recommends this for the combo of pod filters and enhanced exhaust. I then turned Mixture screw from seated position 3 rotations. All this is per Dynojet Instructions.

The issue I have is that it seems to be choking or somthing when i give it good throttle. Plus I can make it to 110 kilometres per hour no problem but it is a litte tougher to get past 120.
I think i noticed it a little wonky at around 5000rpm.
The bike idles nicely.

Any suggestions on healing this problem?

Thanks a lot

 

just a note ont he dynojet kit,,,i also replaced the needles with dynojet needles and drilled the slide lift holes larger as per instructions.

 

I think (according to mine) that you are running rich with the bigger jets in now. I had almost the same setup in mine with stock jets and it ran like a cat on fire.
I have Uni foam in my filter box (just replaced the paper with foam) and with the 4-into-1 Mac system it ran great without any jetting. I have my mixture screws turned out 3 turns and it idles perfect. I recently changed my exhaust system to one from a 650 Maxim and use the shorty mufflers in place of the stock ones and I didn't have to change any settings.

 

Took it out for a test drive again.
Took out the inline fuel filter...no change in performance.
It bogs down when I give it good throttle until it reaches the 7000rpm range.

What to do??

 

Yup - that sounds like running over-rich.

Have you done a throttle-chop plug check yet? Are they getting sooty?

Sounds like you're going to have to open the carbs again and either go to a smaller main jet, or adjust the float heights down 1mm.

Good luck

 

Wow, 136 jets in a 750? That's way too big of main jet, let me guess, your WOT acceleration is soggy and flat, right.

About the biggest jet these old 750's could swallow gas from would be around 117. I have 117's in my 1100 with filter pods, and Kerker 4 into 1 , and it pulls about the same as when I had 122's.

You need to drop them puppies down to about 114 at sea level, if you live higher go smaller 1 size for each 1000ft altitude.

 

Hey thanks for the help, I dropped the jet sizes to DJ124, and the sparkplugs are tan in colour--no soot, The bike is running prestine!!

 

There's nothing better than havin' a nice tan.

There's some that like to have 'em wearing that "Jaundice-looking yellow" after a good while spent over at the right-hand-side of the tach.

Sounds like you got it dialed-in pretty good.
This is good.

Having another tuned-up-good Yamaha on-the-road riding past the U.S. Made V-two's, stopped, broke-down and awaiting the arrival of their "common-fog-end-gitmee" vehicles ... brings a smile to my face.

Good work.
Goodnight; Gracie.

 

Yeah no kiddin!

It's sounding pretty nice!
Hopefully I can get past my Gear Status!