This quad has reached a point where.... when there is a cold startup .... it runs on only the front cylinder when it is started.

I used to change/clean the rear plug ....but I have discovered that if you rev it up ..... hold it steady at about 5000 rpm ..... for a minute or so.. the rear plug with heat up ?/ clean up? and start firing. Then all is well until the next time it has set long enough to cool off.

Any thoughts ?????

 

I bet a lot of people would say stuck choke. Not the case if it runs fine hot.

Almost sounds like the cylinder is filling partway with gas before you start it.

Possibly about defective choke dumping gas in when it is on, but then turning off when the choke is off.

However, if it is just rich at startup, the plug wouldn't be dirty the next time you go to start it. What do you mean when you say you clean or replace the plug, when did you do that, and what did it look like?

 

NYRoc ... I hadn't thought about this being connected to the choke problem.... hummmm...


It runs fine for awhile ......... but after a while it acts like the choke is part on ....... I have been
told to put a new set of choke springs at the carbs to fix that. Will do that this week.

If I start it ... and it is missing .... I can shut it down.... change or clean the plug .... (always black)
and it will run like new. ( untill it sets overnight .... then the same things happens again)

If I forget to shut the fuel valve off ...... sometimes it will fill one of the cylinders with gas ..... and
hydro lock. ( then I have to change the oil ... etc )


By the Way ..... thanks for all the help you supply to all of us. It has been very helpful to read
through you web site.

 

Nyroc, is it possibly that lovely thing about turning off the gas valve each time you stop the engine to avoid "gas" locking (similar to hydrolocking). Would it only do it in one cylinder though?? I had the problem with both of my cylinders and had to basically rip her apart to drain and clean everything. It only had trouble turning over of course (both cylinders were full of gas), so this is a weird problem.


and yes it is nice to have someone like nyroc and others who know their SH*t to help us poor old chumps out every once and while.

 

I used to be a mechanic. Sometimes that experience comes in handy.

Yeah, I had the fuel lock too. Vforce's second post does suggest a choke spring. His plug is fouled since he says he cleans it, gotta be dark. Plus he says it runs crappily when hot at times too.

Choke Springs.

 

Thanks NYRoc .... I will proceed with changing the springs .... and hope it cures both problems [img]i/expressions/face-icon-small-smile.gif[/img]

 

Yep, choke springs!!!!!!!!!!!!!!!!!!!!

 

Hey Guys,

I had trouble with mine getting gas into the oilpan one time and the dealer adjusted the floats in the carbs. Seemed like it helped some but I had to tear them down and readjust them later. I have the same problem with plugs fouling out though. I'll betcha I have gone through a hundred plugs in almost 2 years time. I tried a hotter plug and they worked better but more money. Any advice on the springs for the choke? I know my dealer replaced my choke cables with a newer one saying that was the problem.

 

i have never had any hydraulic problems, ever. and i never shut off the fuel. "gas locking" or "hyrdolocking" is the same. any liquid in the cylinder, be it fuel or water, will lock it up.
I was a mechanic for 6 years, and for my sprint car. if i spun out, we would pull the car backwards
for about 10 feet to clear the cylinders of unburned fuel. 36 dergrees advance+ methanol alcoholl=
BENT VALVES. quoting my freind forrest.. thats all i got to say about that....

 

Just a thought. Wouldn't a worn float valve needle or a small piece of dirt under the float needle cause the fuel to siphon through the carb while sitting. I would think that this would allow enough fuel overnight to hydrolock the cylinder.