86´ bike -carb hybrid.

[gavicool]

Hello everybody:
I would like to know your opinion about what is the best way to "set up" my bike,because now,I not happy with the way is running,but that is because,I think is assembly like an "hybrid".I´m really confussed and I would like to know your opinion about what it will be the best way to make this bike run "decently".
I bougth the bike with the next extras;
Bike Model 86;
+No V-boost-Dinojet manifolds
+4:1 Kerker
+Full Kit Stage 7
I was happy with the performance of the bike,but because I´m given a "city use" to the bike,I have to be changing/cleaning spark plugs very often(I think that was to rich..),but I keep my bike like it is and I was changing/cleaning the sparplugs regularly,every time that I feel the bike run in 3 cylinders.
Well,I sold the bike to my friend,and I get it back a couple of yeas ago,anyway,my friend change/install next things;
+Cange of K/N air filters set up and install the Original Air box
+Main jet smaller,the rest carb parts of the stage 7 kit are installed,but other issue is that new vacum pistons(original Yamaha part) were installed(craks..) without knowing that with the stage 7 you enlarge the slide lift hole of the slides´s.Right now I have new vacuum slides installed with Dino needless but without the slide hole enlarged(and I do not not the diameter of the drill to enlarged in case I have to do it....)
+Carnburator floats set up to 1.117"= 28,5/29,0 mm
+V-Bost tapped(dinojet manifolds no comunicate 1 and 2 eather between 3 and 4,a tap is installed)
+4:1 Kerker still installed
Well,the bike runs like %$¿=& it..and ,at least in the "worst case" I want to get the bike run like before.
I think,the best "option" is go back of how I have it in the past before I sold it and try to adjust the carburation.,what do you think?
Best regards

 

[[email protected]]

Sounds like your running a DynoJet Stage 7 carb setup with the OEM airbox?
I'd look into getting a new airbox lid from Sean Morley. It will fit the OEM airbox but allow use of a large, flat, air filter. You need more air to continue with the stage 7.
Not everyone feels the need to drill out the hole in the slide. Try to tune everything before you do. If needed, it takes a #19 bit.
Check out the carb setup threads for ideas on where your jetting should be.
https://www.vmaxforum.net/threads/oem-carbs-post-your-setup.16981/

 

[Traumahawk]

With the stock airbox installed (stage 7 kits also have air correctors installed in the carbs.....as part of the kit), your starving the bike for air. Either get a muscle jet kit lid from Sean Morley ([email protected]).....(best choice), or you have to go back to the pod filters.

 

[gavicool]

Sounds like your running a DynoJet Stage 7 carb setup with the OEM airbox?
I'd look into getting a new airbox lid from Sean Morley. It will fit the OEM airbox but allow use of a large, flat, air filter. You need more air to continue with the stage 7.
Not everyone feels the need to drill out the hole in the slide. Try to tune everything before you do. If needed, it takes a #19 bit.
Check out the carb setup threads for ideas on where your jetting should be.
https://www.vmaxforum.net/threads/oem-carbs-post-your-setup.16981/

Hello and thank you for your replay.
The OEM air box has a KN filter installed on it,but my big concerns are next;
As I just find out from the last owner;
*New MAIN JET was installed(smaller than the Stage 7,he does not know the size)???????I think are the originals size...but I´m not sure...
*VBoost manifolds tapped(NO comunication-blocked- between cylinders 1 and 2 and between 3 and 4)..WTF!!!!!!????

Thank´s again for your help.

Best regards.

 

[gavicool]

With the stock airbox installed (stage 7 kits also have air correctors installed in the carbs.....as part of the kit), your starving the bike for air. Either get a muscle jet kit lid from Sean Morley ([email protected]).....(best choice), or you have to go back to the pod filters.

Thank´s Traumahawk..what do you think about Factoypro Kits?

 

[Fire-medic]

You do not need to use the K&N pod air filters with the Stage 7 Dynojet kit. I run full VBoost and a replacement K&N element in the stock airbox with a UFO 4/1, a DJ Stage 7, and the bike runs well throughout the rev band. If you already have a Stage 7 kit, I don't see any need to switch to a Factory Pro.

Drilling the slides is a good idea as it allows them to be more-responsive for the DJ jetting you have. Way-back when, people used to tie-together a few coils of the throttle slide springs, to shorten them, so they would react more-quickly.

Remember that the Dynojet #'s are higher in # than the Mikuni #'s. I am not sure where you are, but unless you're at 5,000+ ft. your jetting changes for altitude really-aren't much of an issue. Many people find that leaning-out the main jets 1 or 2 sizes helps, the factory keeps the jetting rich to keep from someone harming the engine with extreme-use.

I think you need to remove the carbs and to see what's going on with the VBoost manifold. The DJ way is to remove the butterflies system, and to run open tubes between the front and rear cylinders' intake passages, where the butterflies were. Totally-blocking-off the front-rear passages? That's crazy-talk! I can honestly-say that I've never-heard of that unless you're speaking of a Japanese-market VMax, which I am pretty-sure doesn't come with any VBoost hardware. I think your prior owner was clueless about what was done, and the only way to be-sure, is to open the system and see if in-fact the VBoost passageways are connected front to back, or are plugged-off, front to back. That would be a first for me, and I've been on mine 27 years.

 

[gavicool]

[email protected]

You do not need to use the K&N pod air filters with the Stage 7 Dynojet kit. I run full VBoost and a replacement K&N element in the stock airbox with a UFO 4/1, a DJ Stage 7, and the bike runs well throughout the rev band. If you already have a Stage 7 kit, I don't see any need to switch to a Factory Pro.

Drilling the slides is a good idea as it allows them to be more-responsive for the DJ jetting you have.

Remember that the Dynojet #'s are higher in # than the Mikuni #'s. I am not sure where you are, but unless you're at 5,000+ ft. your jetting changes for altitude really-aren't much of an issue. Many people find that leaning-out the main jets 1 or 2 sizes helps, the factory keeps the jetting rich to keep from someone harming the engine with extreme-use.

Hi and thank you for your comments and recomendations.
What about the VBoost?.It was removed in the past..and now the original Stage 7 manifolfs were "manipulated" by tapped it,like the VBoost was close all the time,isn´t it?
BR

 

[gavicool]

...and I live "at sea level"...and I agree with you about the jetting issue...thank´s.

 

[Traumahawk]

Thank´s Traumahawk..what do you think about Factoypro Kits?

I like the factory pro needles (needles are what really makes a kit). I use FP needles and MK jets. The stage 7 needles work pretty well though, and can be tuned for the street.

The problem with using the stock airbox and air requirements is the plastic piece on top of the airbox. With it bolted in place, it will limit the amount of incoming air.....to what a stock motor needs. If a full stage 7 kit was put in, then air correctors were put in as well. I remember Dave "Spec ops" having issues with tuning, because on a set of carbs, 1 carb had an air corrector installed.....and the other 3 didnt.

You can still retain the factory airbox with a stage 7 kit if you take the Y off, and widen the hole in the to where it is equal with the rubber lip for the K&N filter. Its easier with pod filers or swapping the top to the muscle jet kit top that Sean Morley sells.

Take some pictures.....of the top of the carbs looking down, and of the Vboost, and quite a few people on here can help determine if you have the Vboost elimination tubes (which come with the stage 7 kits) and whether or not you have air correctors installed. To actually tune the carbs, you will need to get into the carbs and see what the jets are. Please post pics.

Here is how to get into the carbs.

https://www.vmaxforum.net/threads/how-to-change-main-jets.3570/

Please post what you find.

 

[gavicool]

I like the factory pro needles (needles are what really makes a kit). I use FP needles and MK jets. The stage 7 needles work pretty well though, and can be tuned for the street.

The problem with using the stock airbox and air requirements is the plastic piece on top of the airbox. With it bolted in place, it will limit the amount of incoming air.....to what a stock motor needs. If a full stage 7 kit was put in, then air correctors were put in as well. I remember Dave "Spec ops" having issues with tuning, because on a set of carbs, 1 carb had an air corrector installed.....and the other 3 didnt.

You can still retain the factory airbox with a stage 7 kit if you take the Y off, and widen the hole in the to where it is equal with the rubber lip for the K&N filter. Its easier with pod filers or swapping the top to the muscle jet kit top that Sean Morley sells.

Take some pictures.....of the top of the carbs looking down, and of the Vboost, and quite a few people on here can help determine if you have the Vboost elimination tubes (which come with the stage 7 kits) and whether or not you have air correctors installed. To actually tune the carbs, you will need to get into the carbs and see what the jets are. Please post pics.

Here is how to get into the carbs.

https://www.vmaxforum.net/threads/how-to-change-main-jets.3570/

Please post what you find.

Hi,thank you for your information and recomendations about it.
I will post pictures and acurate information about my carbs set up as soom as posible,in that way it will be easy to fix the problems.
In this moment,the carbs are installed in the bike,I was thinking to remove then and inspected,the bike was stoped for 2 years in the garage...and I would like to inspect/clean the carbs,and at the same time take notes about what really it´s install it.
About the link that you post(by the way..very helpfull..thank´s),a menber
VmaxVboost post this .pdf file that it is not aveilable any more;
http://www.djbaparty.com/file_uploa...l, float bowls, and main jets, March 2009.pdf
Do you have this info. available?
As soom as I get all the information I will post it,in the mean time ,thank you again for your help.

Regards

 

[Traumahawk]

I dont have that exact info available.

It looks like this. https://www.vmaxforum.net/threads/how-to-remove-carbs-and-access-float-bowls.12556/

Also in the carb section, is anything that you want to know about Vmax carbs.

https://www.vmaxforum.net/forums/carb-tuning.6/