Hi I am new to this, but I really need help!!!!
I was riding my 86 trx 250r, I was riding it for a good while,
It was bogging for a bit but stopped, I kept riding it
But after a lil bit it started bogging more. The more throttle
I gave it the more it would bog, then it just died on me.
The kick start got very loose, and it wouldn't start after that. It was also leaking from the the top end cover. Can some one plz help me I really love this quad and I want to get right back on it.
Anyone got any ideas what could be wrong??????

 

Welcome to the forums.
Sounds like you have a blown head gasket (leaking).
Altho, it could be a plugged jet, bad reed, or bad piston (kickstart loose).
I'd start with the head gasket and see what's going on.

 

Okay thank you, i was thinking the same but not to sure, any idea on why it died on me while riding?

 

Yes, I have a fair idea on why it quit.

"Sounds like you have a blown head gasket (leaking).
Altho, it could be a plugged jet, bad reed, or bad piston (kickstart loose).
I'd start with the head gasket and see what's going on."

All that could be why....LOL
When it did all that on me, I squeaked a piston (boom).

 

Lol yea bro, well I took a look at the top end and the gasket was actually ok, but going to buy another one just to be cautous, but I just looked at the piston and it was busted, it looks like its been stratching, inside the sleeve, what is the process on replacing the piston? Would I need to resleeve it? Or would I just need to clean up the sleeve, and just replace the piston? Also how can I prevent this from happening again bro?

 

Lol yea bro, well I took a look at the top end and the gasket was actually ok, but going to buy another one just to be cautous, but I just looked at the piston and it was busted, it looks like its been stratching, inside the sleeve, what is the process on replacing the piston? Would I need to resleeve it? Or would I just need to clean up the sleeve, and just replace the piston? Also how can I prevent this from happening again bro?

 

I'm guessing the top end had considerable time on it. Once extremely wore, the slapping of the piston to wall finally cracks/breaks the pistons.
You'll need to figure out what size piston is in it. Then you will order a .5mm bigger piston. Then you take it to a shop that does cylinder boring and they fit the piston in the cylinder.
I prefer stock (cast) pistons. ie: honda/pro-x/Arts.
Make sure you order the 86 piston. You have the ATC/TRX short rod.


The key to logevity is a well lubricated foam air filter with a aftermarket foam pre-filter on it, and regular maintenance.
Gas sucks these days. If let to sit, sta-bil/sea-foam is mandatory. Fresh is best and high octane always.
I mix a good synthetic oil at 32:1. The tank says 20:1 but the oils have come a long way since 1986.
You need to keep an eye on the plug color (jetting). White=lean..black=rich. A light chocolate brown is best.

 

Yea lol I just traded my truck for this quad and I'm in love with it till it messed up, the person that I traded for it told me it was rebuilt, but I just found out that it was rebuilt 3 years ago lol and that he only used it twice sence he got it rebuilt.
From the way it looks like inside, it looks like its been worn out and used up.

Any idea on how much it'll cost to fix this?

 

By the bro thanks for the help I really appreciate it

 

Lt80: is your 250r stock or modified?