when i bought this bike i didnt know how it was supposta run so i started doing some maintnance, i changed out the fuel filter and it woke up, unfortunatly all that rust in the filter passed on to the carbs. i removed the tank and had it redone and replaced the enw fuel filter and rebuilt the carbs. after that it ran great for a while then started fouling plugs. the main jets that were in it were 175 its got individual k&ns with 4-1 kerker. i took the carbs off and changed the main jet to 165s and pulled the needle out 1 space. still fouling plugs. found that my regulator wasnt working so i wasnt getting a hot enough spark. replaced that and then the bike seemed to run great but the plugs are still very black not that cocoa brown color they were when i first got the bike. it still seems to foul out the plugs after a few passes at the strip, i even went to drp7 to help burn the fuel and no luck. please help, sorry this is so long just wanted to get the whole story out there.:bang head:
Help Support VMAX Forum:
With Stage 7 and Kerker 4-1 152.5's work best. DJ 165's are a bit richer than stock so you can either try DJ 160's or even DJ 152.5's.
For your needles did you move the clip towards the blunt end or pointed end?
When you rebuilt your carbs what did you set your floats to?
For your needles did you move the clip towards the blunt end or pointed end?
When you rebuilt your carbs what did you set your floats to?
moved the clip towards the blunt end, it is now setting at 1 from that end. i dont know what the float levels are at unfortunatly, are the 152.5s gonna lean it out i thought stock was 154. ill try and provide as much info as i can i dont know a whole lot about carbs and i just ordered some nitrous so i need to get the bike running right before i blow it up. the at the strip it felt like it was running lean on the top end, thats why i moved the needle to richin it up, please correct me if i was wrong in doing this. it felt alot better on the top after this but fould out the plugs after just 2 passes.
So you can lean the needle out anymore?
Stock is 152.5 and the jets go in increments of 2.5...for Mikuni anyway. DJ jets go in increments of 5.
Is it possible you have sticking floats? How does your spark look?
Stock is 152.5 and the jets go in increments of 2.5...for Mikuni anyway. DJ jets go in increments of 5.
Is it possible you have sticking floats? How does your spark look?
ok i just went to the garage and looked at the spark, from the plug to ground it has about an 10mm ark looks to be strong but thin blue/orange. if moving the clip towards the point is leaning it out then yes i can lean it alot more. i dunno how i can tell if the floats are sticking. i thought the aim of a stage 7 was to put in more fuel and air?
Moving the clip towards the point richens the midrange.
CV carbs work a bit differently. With four individual filters you lower the intake velocity. Plus, Vmax like the mixture on the lean side. Shoot for 12.75-13.25:1 a/f ratio. If the floats are sticking open you might see fuel come out of the main air jet up top and/or float bowl vents.
What's your compression? Have you done a valve adjustment lately? Is your vboost stock or open full time? I'm assuming you are using DJ slide springs? Try using stock springs instead.
CV carbs work a bit differently. With four individual filters you lower the intake velocity. Plus, Vmax like the mixture on the lean side. Shoot for 12.75-13.25:1 a/f ratio. If the floats are sticking open you might see fuel come out of the main air jet up top and/or float bowl vents.
What's your compression? Have you done a valve adjustment lately? Is your vboost stock or open full time? I'm assuming you are using DJ slide springs? Try using stock springs instead.
with the filters off i can see fuel spitting out of the top of at least one carb and a little out of the rest but mostly the left rear. to my knowledge ive never had a valve adjustment, never checked compression, no vboost, and most likely dj springs, the kit was on the bike before i bought it and from the looks of the header, has been on there a while. i found a tech here in town that claims he put the kit on 6 years ago, ive had him doing the carbs since i got it about a year and a half ago, it has 35,000 miles on it.
ok update: i took the carbs off and checked the floats they were fine, put the stock main jets(152.5) back in the bike, syncronized the carbs and the thing still is running rich as hell can tell if its a low end issue or a top end issue as i dont have a wideband o2 or a dyno to strap it to without paying 150 dollars. tommorow im going to pop off the valve covers and do a valve adjustment as to my knowledge it never been done. anyone have any other suggestions short of buying new carbs? thats not gonna happen.
Is your vboost closed at idle? Are all four of your choke plungers closed? They operate finger looking things. The plunger is on the left side of each carb.
KJShover
Proud Vmax lover
TURBOVMAX
Well-Known Member
Before you go pouring juice to the thing... I would do a leak down test to see where you stand with that engine. A simple plug check at the track will tell you if your running the right mains. Do you know how to do that?
"Is your vboost closed at idle? Are all four of your choke plungers closed? They operate finger looking things. The plunger is on the left side of each carb"
the vboost isnt connected, wouldnt it be closed at idle? i dont reeally know how to check that. ill check the choke plugers tonight, last night i checked the valves and only had 1 intake valve that was a little tight, the rest were fine. i dont think im gonna be sprayin this thing anymore, now im just more concerned with getting it running right. how do i know if the plugers are closing all the way? they are all operating and seem to be, is there a way i can be sure? tonight im gonna put the valve covers back on and do a compression check and a leakdown check along with the other suggesions made. thanx for the the replies.
the vboost isnt connected, wouldnt it be closed at idle? i dont reeally know how to check that. ill check the choke plugers tonight, last night i checked the valves and only had 1 intake valve that was a little tight, the rest were fine. i dont think im gonna be sprayin this thing anymore, now im just more concerned with getting it running right. how do i know if the plugers are closing all the way? they are all operating and seem to be, is there a way i can be sure? tonight im gonna put the valve covers back on and do a compression check and a leakdown check along with the other suggesions made. thanx for the the replies.
Your vboost is unplugged? It could be unplugged in the open position. Only way to know is remove carbs and feel for the valves in the intake crossover tunnels.
Choke plungers are closed when the center pin is pushed in all the way. Sometimes the forks that pull the pins bind and don't allow the pin to be pushed all the way back in thus causing richness problems.
Choke plungers are closed when the center pin is pushed in all the way. Sometimes the forks that pull the pins bind and don't allow the pin to be pushed all the way back in thus causing richness problems.
there is no v-boost at all the pipes between the intake runners have been replaced with straight pipes that have no butterflies in them. the valves were good. put the bike togther last night. im really just getting tired of messing with it. im about to leave for the air force in a few months and i dont need it just sitting around while im gone so i think its time to pass it to someone who enjoys messing wtih them more than i do...
