What is the tunin deal goin on here?

[spottedsquirl]

Hi everyone. I have an '85 Max. K&N air filters, DJ stage 7 jetting, 165dj mains, both pj's 170 and 90. DJ needle on the last clip with out shim. F/A mixture screws 2.5 turns out. Slides are drilled from what I can tell, I bought it that way. And DJ slide springs. Super Trapp exhaust with 6 discs on each side.

Hopefully, I got all my info there. Before I did a complete carb overhaul everything above was the same except the needle clip position was third down with shim. And stage 7 vboost eliminator tubes installed. Bike ran ok. Doesn't want to idle down when close throttle for a second or two. Oh, and I'm getting like 47 miles before reserve light comes on and around 60 miles before it runs out.

After complete overhaul, includin complete disassembly and boilin lemon juice acid bath to all parts. All new seals includin throttle shaft seals. New diaphragms on slides. Needle clips on last leanest setting. Floats are closely balanced between 16 and 17 mm as directed on this forum. Vboost butterfly reinstalled. Vboost servo does not appear to be workin but I don't mind that at the moment as long as the vboost stays closed for now. Otherwise bike acts the same as before. Doesn't want to idle down for a second or to from throttle close, at any idle or throttle position and still getting 47 miles to reserve and 60 til empty.

What am I missing? No vacuum or air leaks around the carbs or manifolds. New throttle cables installed and throttle moves freely. I just don't understand the fuel consumption issue. It seems to me that the idle issue and fuel consumption is somehow related. I don't want to take it to the stealership or the shade tree rip off artist. Please help!

Sent from the open road using Vmax

 

[[email protected]]

I have 2 questions concerning the hanging idle:

1. Did you synchronize the carbs? This is a necessity after R&R the carbs. Even more so if you tear them down for a rebuild.

2. If you're running stage 7 filters did you double check that air correctors have been installed?

 

[[email protected]]

Stage 7 carb mods are recommended to be used with a full, aftermarket exhaust system. Sounds like you have stock head pipes and supertrapp slip ons. You may have a hard time tuning that in.

Another question for you:
Where did you find throttle shaft seals?

Any vmax owning friends near you? If so, you could swap carbs to see what happens.

If you're looking to farm the job out to the pros, both Dannymax and Sean should be able to help out.

 

[spottedsquirl]

I have 2 questions concerning the hanging idle:

1. Did you synchronize the carbs? This is a necessity after R&R the carbs. Even more so if you tear them down for a rebuild.

2. If you're running stage 7 filters did you double check that air correctors have been installed?

They are synced but I will recheck that this weekend.

The correctors do appear to be installed.

Sent from the open road using Vmax

 

[spottedsquirl]

Stage 7 carb mods are recommended to be used with a full, aftermarket exhaust system. Sounds like you have stock head pipes and supertrapp slip ons. You may have a hard time tuning that in.

Another question for you:
Where did you find throttle shaft seals?

Any vmax owning friends near you? If so, you could swap carbs to see what happens.

If you're looking to farm the job out to the pros, both Dannymax and Sean should be able to help out.

I was concerned about the tuning difficulty after some of the research I've done and it has proven to be just that.

The shaft seals I got new off eBay from another mikuni carb. The seals where same i.d. and o.d. but half as thick so I double up on them and worked great without any binding or sluggishness.

Sent from the open road using Vmax

 

[Nubicon]

Make sure the flat stamped throttle bar that links the left bank to the right bank is installed correctly. When I first put mine back together I had it flipped around and managed to bend it a tiny bit. That caused exactly the symptoms you are describing.

 

[sdt354]

+1 to what Mike mentioned regarding exhaust. With stock pipes, I'd not bother putting a stage 7 or similar kit in. Just a main jet change to 150 or 147.5. it all starts with a better flowing exhaust system IMO.
Steve-o

 

[caseyjones955]

Those are pretty big mains. DJ and MK jets are not numbered alike, conversion charts are a google search away, I cant seem to link one here. General consensus is that installing a DJ kit according to the directions will leave you with one rich running mofo. I had the stage 1 DJ kit installed by the book at a local shop by PO, undoing that piece by piece was the right move to get it right. I was not only getting lousy MPG but it had rich stumbles and I was constantly being followed by the smell of unburned fuel. Im at MK 147.5 mains @3300' with Kerker and Morley filter lid.

 

[Ted Drum]

Bad gas mileage and poor idle on older VMAX is caused by the rubber around the choke jet, holding the the jet open and the weak choke jet springs. Start the bike, select choke off, with your finger push the choke jets in on each carb, if any jet pushes in you have found the problem. A little lithium grease on the rubber boot will free up the jet (check that the nut holding the jet in place has not come loose. Caution the choke linkage should not push the jet in as it could damage the jet. Before you sync the carbs ensure to push all the carb jets in or you will have wasted your time. # 4 jet was stuck open 1/16'' and the bike that would go 200 km to reserve empty ran out of gas at 150 km. Ted drum [email protected]

 

[thunder]

Th DJ needles, drilled slides will cause an excessive rich mixture. It's hard to beat a well tuned stock set up. The mains are rich from the factory, 147.5 me would work well with stock needles and removal of the air restrictors.

 

[sdt354]

Bad mileage? Float levels- critical. Overly rich A/F screw settings too. Idling and low RPM burn lots of gas too. Stage 7 & Morley carb kits can be very fuel efficient. Your flowing much more air than the OEM air box. +40 mpg set up correctly. It does take time and some trial & error.