KymcoForum.com
Motorcycles => Venox 250 => Topic started by: capthmm on June 24, 2013, 02:21:00 AM
-
First of all, glad to see there is a forum out here and it looks like a really good community!
Now for the problem - I bought a 2003 Venox a few years back, rode it quite a bit, but eventually garaged it more and more due to the insane Texas heat. Yes, riding in August fully armored up is like riding in an oven and not very enjoyable. After being parked for a while with a low level of gas in the tank, it began to run rough, so I assumed there was moisture in the tank, so I pulled it, cleaned it out and put in fresh gas. It ran great after the cleanup - so good that for whatever stupid reason, I decided that it was idling a bit higher than before, and I made the poor decision to turn down the idle by using what I assumed was the idle speed adjustment screw/knob on the right side of the bike. The idle dropped and the bike was still running great when I shut it down for the day.
A week or so later when I went to go for a ride, the bike cranked right up and ran while the choke was fully engaged, but began to run rough even after being warm and would only run with the throttle applied and never idled again. From there over the next few years (yeah I know) I've mildly tinkered with the bike (new plugs, attempts to use the adjustment screw) but it's only gotten worse. Strong battery and good spark, but now the bike turns over runs for only a few seconds and then dies.
From my experience restoring cars and a 1977 Kawasaki KZ750 and looking around the posts here I'm guessing something in the carb is blocked or gummed up. If there's anyway to avoid tearing it apart, that would be great to know since my rebuild of the Kawa's carbs wasn't 100% successful and required a trip to the shop to get everything sorted out. If anyone can give me some good advice on where to go from here, it would be greatly appreciated. I'm looking for the shop manual, and noticed on some other posts that some users are willing to zip it up and email it, so if you're offering, I'm more than willing to take you up!
Thanks,
Eric
-
Welcome to the forum capthmm...
I don't have the V-nox... but have you tried browsing the Venox 250 threads here.. they're loaded with information about Venox engine problems and solutions... I think you can get some information there...
-
pull the plugs, if they are fouled... first thing is to change the air filter if it was more then 2 years since you last changed it.
running good before and suddenly fouling plugs and wont idle is most probably air filter.
But if you pull the plugs and it looks clean without fouling and dry then you might have a clog on pilot jet.
hope thats the problem.
-
And from my own previous fouling experience, the venox can not idle on only one firing cylinder, they both have to fire to sustain idle.
Guys another thing to look out for, if your engine is starting to gallop on idle and you do not remember the last time you changed the air filter then its time to change the air filter.
Venox runs lean on idle saves fuel and does not foul plugs. the venox carb has this thing called idle vacuum valve which gives extra fuel on high speed snap shut throttle, and running on high revs the air box restricts air flow making running on high revs richer.
So again if your bike was running good before you stored it and after like half a year of storage it fires up nicely but after a few rides it starts fouling plugs then your best bet is the air filter. thats if you have drained the bowls and filled up the tank before you stored it.
Depending on fuel quality, additives, storage temperature and duration, bowl draining before storage is still like an insurance. you might be able to get away with it, but if you are unlucky that means a carb pull... as that being said check plugs first, if they are fouled then you eliminate that the carb has a blocked jet.
-
Is it possible to drop the fuel bowl(s) without removing the entire carb assembly? I'm unfamiliar with the Venox carb.
-
you can drain them while on the bike but to get them off is impossible without getting it off the bike, too tight without enough space. when you take them off the bike you will still have to take the two carbs apart to release the bowls.
try a new air filter buddy. it costs 10$ they are made out of a paper element which will expire even without the engine running. my bike came with only one hundred km from a show room, ran for a week then will not idle and started to miss fire and foul plugs. cleaned the carbs 3 times till i understand the paper air filter age issue, new air filter and never looked back.
-
OK, I'm going for the path of least resistance first - a new air filter has been ordered. I guess we'll see in a few days.
-
clean the spark plugs with a blow torch and burn off the carbon on the ceramic or get new ones as well while you are at it.
-
OK, so I finally got the the air filter and some time to devote to the bike and met with moderate success. I pulled the tank, drained the old stale gas, cleaned the plugs and checked the gaps and replaced the air filter.
The bike now runs, but only when choked and tolerates some throttle variation, but will eventually die with too much/too little throttle and too little choke.
I found a shop manual online, but the pictures and diagrams of the carb are almost useless, so does anyone have a picture of the bowl drain screws - the manual doesn't show or label it? I'm hoping I can drain the carbs and that will take care of the idling problem.
-
I would try some Sea Foam (gasoline additive) in the gas. This may clean the gum out of the pilot jet /main jet with out a tear down. Put in the correct amount for the tank size. Get the thing running and go for a cruise even if you have to run with the choke on. Then do it again after sitting overnight. It is cheap and often successful.
-
SeaFoam is good but we have found Berryman's B12 to be a lot cheaper and somewhat better at cleaning the carbs.
It never hurts to use 1 for 2 or 3 tanks and then try the next. Techron is different from the other two, and we use it also.
Scoot safely,
-
After sitting overnight and just adding the Seafoam to the gas, the bike now refuses to idle under choke.
Can someone point me to a link or post a picture of the bowl drain screws?
-
Never mind about the screws, I found them by process of elimination and drained the bowls. Now it looks like I'll have to pull the carbs anyhow since gas is draining out of one of the carbs which I'm pretty sure means the float is stuck. :)
-
To anyone that might have been following - the heart of the problem was actually a bad fuel petcock. Somehow or another the diaphragm had gone bad - even at when shut off and no vacuum, the bowls would fill and gas would leak out.
Bike runs great now.
Thanks for all the input.
-
that happend to my as well. but not as bad. just leaking into the rear manifold. good to know you are problem free!