1985 Honda 250sx Questions.

[feo_nuts]

Hello everyone. I just have a few, ok a lot of questions to askk. 1st off when I bought this 3wheeler the dude said it bored up to a 300. Is that possible/true. 2nd and most important is. The airbox on it has 2 tubes, the short fat one,and the longer tube that sucks air out from the frame up under the forks. When I bought this it didn't have that hose (i dont think) I drove it around like a stolen car for about a week. Its got pretty decent power and is fairly fast. After a day of riding the engine started boggin out. It wouldn't even start unless it was on full choke. It will idle. I was dickin with it yesterday and had my fingers around the airbox. I dumped the throttle and it took off (it was chokin itself out) Well that led me to think that I was having a air/fuel mixture problem. I dicked with it some more and put a sock over it and it would rev up real high like it was supposed to. Of course it wasn't like it should. So I guess the questions are..... how important is that hose (i will call it the intake hose)? Why would it have worked before without it and it wont now? Is my carb screwed? Either way let me know please. Talk to yall later :D

[tri again]

aww shucks, you'll be ok.

When I get a trike, I usually start with cleaning the gas tank first.

screaming Hot water and solvents or muriatic acid. depending on how bad they are.

There is NOthing like getting dirty gas into a carb that took a couple days to clean properly and the wrestling match it takes to get them off and back on.

They honestly should run great with the carb open to the air irrespective of the airbox and funky tubes.

I guess people drill holes in airboxes and re route intake air to compensate for bigger exhaust pipes.

I have enuf trouble keeping the honda engineered stuff running so I dont usually modify, personally.

sounds like you got a great machine.

alcohol free or less than 10 percent ethanol is recommended.

alcohol, burns, yes, but it tends to break loose crud and rust that is perfectly happy where it is and has been for 20 years.


I've been thru at least 20 carbs in the last few months so I'm neurotic about clean fuel supply since I do not ever want to do another one.
My new rule is to spend more time riding than working on them


ps

there is a screen on the petcock under the tank\and I'vve also had 2 TWO gas caps that would not vent properly to allow gas to flow.

If you do take the carb apart, make sure you pull the hidden emulsion tube from under one of the screw out jets and make sure the internal passages are clean.

if it ran as well as you said, you are very close to happy trike land

[feo_nuts]

Hey hey awesome! Thanks for the reply. I was messing around with it some more today and I got it to fire. Not all at first though!!!!! It was running fantastic without a problem at all. I noticed that in my carb my "throttle piston" (the big piston looking thing that raises up and down when you throttle) was stuck/sticking up. I cleaned all the crud out of it and it seemed to work great. I think some of my issue is in the choke. On mine, the choke uses something what looks similiar to a needle & seat set up. Anyways the spring on it is all smashed up and stretched out and now I dont think that it is working properly. I mean come on, you sit in gas for 25years and tell me if you ain't gonna rot! Well after a day of playing I got frustrated when I discovered that I didn't have no spark. It was bright as hell so maybe I was just seeing things. I pushed down on the coil terminals and got a loud ass POP! then it ran. like there was nothing wrong. So that leaves me lost, I just kinda put it up for the night. i didn't remove any jets or anything just the throttle linkage cover and the float bowl. Well anyways if you all have any hints on the choke just let me know. I think/hope thats it.