sputter #1 plug wet

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

genecarroll

Well-Known Member
Joined
Dec 2, 2013
Messages
72
Reaction score
8
Location
daytona beach
Im not sure where to post this I have a dillema. 1998 vmax 15000 miles was sputtering under load about 2500 to 3000 rpm then seem to clear when opened up so I pulled apart carbs yesterday everything looked good but I still blew through everything. Put It back together and it was running great yesterday. Went on a ride today was running great for about 50 miles then I decided to jump on it once to show off you know how it is and I now have the same symptoms so before I tear into the carbs again I pulled the plugs they all looked great except #1 it seemed wet so I put a new plug in it and away I went know change I switched coils to see if symptom would go to another cylinder and it didnt. still #1. Let me hear your thoughts please. This bike is driving me crazy
 
How far did you break down your carbs? Does it idle without the choke? Does it stay smooth above 3K? You might have a plugged idle circuit (pilot jet). Shine a flash light into your gas tank and see if there's any rusty looking stuff in there. Take the black plastic part off your fuel pump and see if there's any rust in there especially on the little metal sight-looking things. any rust from the tank will get past the fuel filter and plug those things up super fast.

Posted with my thumbs.
 
I broke the carbs down to the jet blocks pulled pulled jets out and cleaned them the bowls were spotless the tank is spotless it does seem to run well above 3000rpm and idles smooth at 1000rpm I just did the shot gun and took it for a quick spin I think it's better but I got cold and couldn't pay enough attention. Will take out again in the am. I did pull the plug when I got back and seems to be firing at the moment.
 
Pump some gas into a white cup or glass jar. You'll be able to see if any junk settles.

Sent from my Galaxy Nexus using Tapatalk
 
Have you done voltage checks? Could be a weak battery that once you get up above 3k RPM you're getting enough power from the stator to get better spark.

Batteries loose a lot of their capacity when it's cold which could be compounding the issue.
Make sure you have at least 12.0 Volts when idling.
 
I had the same problem only at a little higher revs, more like where the slides start to open at 3800, one or more were slightly hanging up and it doesn't take much. pull the slides and polish really well with a rubbing compound along the length of the slide. Clean up any remaining compound really well and reinstall with a little WD40.
 
I was thinking that was where the problem was because it seems like its a transition point and if it were a plugged pilot jet wouldnt my idle suffer? and yes checked voltage. I'm pretty sure it's in the carb
 
Idle would get worse as more of the pilot jets got plugged. That slide check sounds like a good idea.

Sent from my Galaxy Nexus using Tapatalk
 
Start with the carbs then check the electrics, it could also be a cracked coil or some bad wiring connections

attachment.php
 
I had a similar problem with Skullduggery when I was in the process of restoring everything. It turned out to be the carb in question. Make sure you have an o-ring on the Air Fuel Screw. Make sure the float isn't sticking. I would suggest using the rebuild kits that you got from me and then syncing at a higher RPM. I sync my bikes at 3000 RPM with fans running on them from the front. Most of the guys won't agree with that but it's worked for me on about 25 of the bikes I've owned. I was offered a job as a tuner after a dealer rode an old XJ-1100 I was trading in. Check the slide of the questionable carb to see if it sticks. I spray mine with WD-40. This kind of a problem is a RPITA to isolate so make certain that everything you check is spot on.

Dave in Florida
 
I did rebuild them. Used everything but the seats. Like I said was spot on running great then sputter after I opened it up. I did look at the air filter better and the foam seal at the top is deteriorated im wondering if when I pulled all that air in if it pulled some foam from the filter through air jet. Possible or wishful thinking???????
 
Well I blew the pilot air jets out all around and that seemed to do the trick. Rode most of the day and it's running great again. Went ahead and ordered a new filter so hopefully not have this problem again. Would be nice just to ride it for a change.
Thanks for all the input hopefully this can help someone else. Obviously these air jets are very sensitive.
 
Cool, Congrats. Ride Safe and don't have too much fun.:clapping:
I was going to take all of my bikes out today just to run some gas through them but it's raining really bad on this side of Fl.. It's coming your way so you may get some later today.:confused2:
 
Back
Top