Good Place for ATV Repair Info?

[Clarkbug]

Just curious if anyone here has a go-to forum that they would use for ATV questions/information.

We were given an older Yamaha Moto4 by a family member a few years back, and it needed some TLC. Its up and running again, but makes a kind of knocking or clunking in the rear when you ride over bumps or push down on the back end. Doesn't seem to be impacting anything, but I am worried there is something I need to address before it grenades and creates an expensive problem. Wanted to find a spot to ask for input instead of just starting to tear things apart and hoping to find a smoking gun.

 

[RCBS]

Don't know where to tell you to look but I used to thrash one of these back in the early 90s. They'll go up hills you wouldn't believe. lol

 

[Clarkbug]

This one was used mostly as a utility wheeler by the original owner, then passed to my BIL that was...less than kind to it. Apparently he didn't realize that the screen in the air box is just there to hold an actual foam filter... And he tried to fix an issue with the starter clutch by taking the case screws out with a regular screwdriver. So, I got a little bit of a box o' wheeler for the cost of moving it around if I wanted to try and fix it. Some eBay parts to the rescue, and it runs and drives. I will say it does NOT like to start when cold at all, so Im wondering if I have an issue with the valves, cam or if its just low on compression. Need to put a tester on it and see if I need to do a top end. But would like to figure out my mystery clunk in the rear first before I spend too much more on it. Seems like a well made, easy to work on wheeler.

 

[hacskaroly]

Seems like a well made, easy to work on wheeler.

I would say post pictures and ask questions, seems like we have a wealth of knowledge about things other than chainsaws here on the forum too!

 

[legdelimber]

Never owned any 4 wheeler stuff.
But If I were to walk up and try to find the issue, this is just what I would start with first.

Lets look at the common stuff related to suspension.
Shock absorber bushings. Cracked or Broken mounts for the shocks.
What sort of linkage or swing arm caries the axle?
Is there a differential housing that could be cracked?
Any chain guard or cover parts that might be loose?
Again, look at all pivot or flexing pieces.
Do any bearings seem to be sloppy?
Wheel hub and bolts or lugs, etc loose?
Perhaps a cracked rim.

Broken exhaust mounts letting something bump?

Where are you pushing on the machine?
Any body panels, fenders or seat loose, etc, that might be moving and clunking.
Heck even handlebar mounts and such.

Then look around for something that might be loose or bent and possibly touching as the suspension goes through its travel.

edit: If need be, get a friend to help push things while the other person looks at the machine.
Just be careful and don't get your fingers or your head pinched while anyone pushes on the machine.

 

[legdelimber]

One more that I missed.
apply either the front or rear breaks, separately and the while you push the machine
Take notice of if the sounds, each time you change from or rear breaks.
Also try it with both front and rear applied together and notice if things change.

does having it in gear Buyt not holding the breaks make a difference in the sound?

 

[Bill G]

What year is it? Post a pic of you can.

 

[bucketofguts]

My 2003 Kawasaki Prairie 650 , 633 cc. I have a Warn winch on the front. Many internal mods. Back in the day. Have a look.We would drag race one weekend, ride 100's of miles around Welch WV with the locals the next. Mostly trails where we would not see anyone else. Glory days!

 

[RCBS]

This one was used mostly as a utility wheeler by the original owner, then passed to my BIL that was...less than kind to it. Apparently he didn't realize that the screen in the air box is just there to hold an actual foam filter... And he tried to fix an issue with the starter clutch by taking the case screws out with a regular screwdriver. So, I got a little bit of a box o' wheeler for the cost of moving it around if I wanted to try and fix it. Some eBay parts to the rescue, and it runs and drives. I will say it does NOT like to start when cold at all, so Im wondering if I have an issue with the valves, cam or if its just low on compression. Need to put a tester on it and see if I need to do a top end. But would like to figure out my mystery clunk in the rear first before I spend too much more on it. Seems like a well made, easy to work on wheeler.

They built them simpler back then. Honestly the Moto 4 is just a TriMoto with a different front end on it. Suzuki also used this approach in the early years. I consider late 80s and early 90s quads to be nearly bomb proof. Big Bear, Honda 300 and King Quads are some of my favorites. Wouldn't hesitate to buy a well kept one today if the need arose.

 

[bucketofguts]

You need a true guru that works on ATV's. One that can fix a Honda's auto styled tranny, or a CVT w/o batting an eye. They will be backed up weeks or better. I still have my ATV guru, but lost my chainsaw main man that would drop what he was doing and take a look at mine. He was only 87. Fell in the bath and was hurt pretty bad and gave it up. Good luck to ya! Cool vintage ATV by the way!