I just bought a 88 LT80 for my son, and one of the first things I did was change the pipe from a DG back to a stock pipe. I bought a new one from ebay, the old pipe is LOUD and my son was kinda scared of it.

After replacing the pipe, everything ran fine for several days of yard riding, until we drove it 100 miles away to ride. It would not crank (boy was he disappointed!). When we got back, I started checking and found that the new pipe and muffler was FULL of fuel. I mean a lot. I took it off, and changed plugs and tried to crank it (without a pipe). The carb is blowing fuel from the exhaust port.

I am thinking I need a carb rebuild kit. The guy who had it before me had rebuilt the engine better than stock and changed jets in the carb. My question is, should I be able to get a stock carb kit and put it back stock? Is this most likely my problem (or something else in the carb)?

Since he rebuilt the motor previously, is there something he may have done in there that requires the rejetted carb and exhaust, or will putting it back stock be OK?

Thanks for any help!

 

My best guess is that with the stock pipe on the bike the jetting is now way too rich...but the odd thing is that it ran fine for several days...usually that problem would manifest itself immediately upon start up and the first few minutes of running.....

Here is a question for you....

When you transported it did you tip it up on end to save space??....if so you could have loaded it up on fuel and/or the float could be stuck....try opening the drain on the bottom of the carb bowl and tap the bowl slightly while the fuel is running out.

 

It was sitting flat on all 4 wheels while transporting it. I have turned the screw to let gas out and tried tapping it to see if the float is stuck, but cannot tell anything. I think my next step is to take the carb off...

While it was running, it was smoking white pretty bad, but I did not take to much notice of it (computer guy here, not engines). Now that I think back on it, it was probably pushing way too much fuel out.

 

Well that is really wierd that it ran fine for a while...

So yes...rejet the carb back to stock and see what happens...and also make sure to dump your oil and change it before running it as the crank case is probably full of fuel which will break down the oil.

Good luck!

 

Surely you will need to clean the carb. Should of been done when you got it IMO.
My question would be: what position was the petcock in? It is a vaccum operated petcock which means that off is on, till the motor turns. In the prime position, it runs fuel constantly.
BTW,, this happens. I call it the "great debate" as ppl think it's the petcock, float needle in the carb bad or plugged open, and/or too much hydraulic weight of the fuel allowing the motor to fill w/fuel.

The fix:: A simple on/off valve from a autozone. About 4 bucks I think.
The carb kit may be a good idea as it will give you a new gasket plus a new needle/seat. I'm unsure if jets are included.
Stock jets are 17.5 and 92.5 If he put a smaler main jet in, (87.5 or a 90) it's OK to leave them in. If bigger, then go back to stock.

Stand the machine up on end (with the petcock off) and empty the motor/pipe of fuel. Remove the spark plug and allow to dry a lil bit. Hold throttle wide open till it starts.
Hope that helps. [img]i/expressions/face-icon-small-smile.gif[/img]
Motor better than stock eh.. I'm guessing that this guy put a Wiseco piston in it only. Some ppl think this is a big deal.
IMO: there is nothing he did that required a jetting change.

 

I have learned a bit more since taking much of it apart. The petcock is stuck open (flows all the time) with an added fuel valve. My son left the added valve open all night, so that may have caused the problem, this will be something we will have to watch, or replace the original petcock (expensive though).

I am ordering a rebuild kit today and will let everyone know how it goes. Thanks for the help!!

 

just put a inline shut off off a lawnmore in the gas line that goes from the petcock to the carb that will fix your problem. dont spend the money for a petcock. unless you like wasting it.

 

<div class="FTQUOTE"><begin quote>Originally posted by: Xeller8





and also make sure to dump your oil and change it before running it as the crank case is probably full of fuel which will break down the oil.



Good luck!</end quote></div>

while your at it change the air in the tires. it might have mold in it!!!!

 

Do I need to remove the tires to get all the moldy air out, or just let the air out and refill??

I kid, I kid... :-)

 

Your bad ZJ. [img]i/expressions/face-icon-small-happy.gif[/img] [img]i/expressions/face-icon-small-happy.gif[/img]