Jump to content

  • Do you own an ATV? Join our Forum!

    As a member, you can post in our forums, upload your photos and videos, use and contribute to our downloads, create your own member page, add your ATV events, and even start your own ATV club to host your own club forum and gallery.  Registration is fast and you can even login with social network accounts to sync your profiles and content.

Recommended Posts

Well let's start from the top. I mentioned to a family member I was wanting to pick up a few more 4 wheelers. He mentioned he might let loose of a 700cc that he had just purchased due to back problems and not being able to ride anymore. I asked what he was looking to get for it. He said $1500. So, naturally I loaded the trailer up and went to look at it. I took it for a test ride and it rode really well for about 15 minutes then overheated. I checked the dipstick and the crankcase was filled to the brim with milky oil. He said the shop he bought it from replaced the head gasket and it was supposed to be fixed. He said forget the money just take it with me and see if I could get it fixed. So, she came home with me.

686cc single cylinder, CVT transmission, 75 miles on the odo, 750lbs dry, 33.5hp, liquid cooled, electronic 4wd with electronic locking front diff, 4 wheel independent adjustable suspension, winch etc. etc..

This bike is modeled very closely with a Yamaha Grizzly 700.



The teardown begins


Winch, horns, and radiator



Looking from the passenger side, header, cylinder head and water outlet. The black cover at the bottom covers the CVT section of the trans.


From the rear...interesting, it has a single pinion brake on the rear where the front has brakes mounted at each wheel.


From the driver side, oil fill cover, cylinder and head, coolant overflow, and pull start


Share this post

Link to post
Share on other sites

The front diff


Pulled the valve cover. The contraption bolted on the front of the cam sprocket is the compression release. How it works is simple: The weights on the front pivot and are held in place with spring tension. They are connected to a shaft that runs inside the hollow cam. When they are in a "resting" position, the shaft activates a knob on the backside of the exhaust lobe. When this knob is raised, it blips the exhaust valve open during the compression stroke relieving some of the cylinder pressure. At the point the rpms raise above cranking, the spring force is overcome allowing the weights to pivot which pulls the knob back flush with the exhaust lobe's smooth side thereby preventing the compression to be released.


You can see the holes in the cam for oiling here. The pressurized oil is carried to the cam journals by a hard line that is on the exterior of the engine. The brass lines at the top are EGR. It has a frame mounted pump.


With the camshaft removed, you can see the freeze plugs. Typically these would exit the engine but these exit into what is essentially the crankcase. These were replaced with new ones in-case these leaked.


I pulled the cylinder head, the black thing sticking out is the adjustable timing chain tensioner. In this pic you can also see the oil filter, starter, and front driveshaft.



I pulled the cylinder and it got a new base gasket. I wanted to fully inspect it for cracks/issues.



5 valve cylinder head. 3 intake, 2 exhaust. It has an MLS head gasket.


Share this post

Link to post
Share on other sites

Each exhaust valve gets its own port and header pipe. They merge into one later down the line.


One carb, splits into two runners, then the larger of the two splits again to feed the 3 intake valves.


The bottom side of the rocker cover. The rockers are shaft mounted to the cover. One of the intake rockers actually opens two of the valves and it is controlled by one really wide cam lobe. So, 4 lobes total to open 5 valves. Interesting.


MLS headgaskets getting the copper treatment


Reassembled, fresh oil, cleaned the entire cooling system and whaddya know. Same exact problem. Open her back up and what do we see:


So she ended up getting a new cylinder head.

To ensure I can keep close tabs on the coolant temp I ordered a Summit gauge, and used a Glowshift universal pod.


The original sending unit fed a dummy light. So I exchanged it with the sending unit for the Summit gauge. It's located in the thermostat housing. Ironically they do not fit these engines with thermostats. This engine likes to run 170-180 from what I've seen.


I've put a few miles on it since being back together the last couple of weeks and I can say without a doubt, this is the nicest and fastest chinaman 4 wheeler I've ridden. With the CVT trans, it's like having a big ass torque converter. From a dead stop, it stalls up quickly to 4200 rpms, and that seems to be the "variable" section where the gearing expands, you accelerate quickly and the top end really comes alive. It tops out around 55mph and probably 6500rpms.

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Tagged Content

    • By SG082279
      my quad stalls and cuts out ..
      and i just put a band new carbarater what else could it be
    • By Bajarider
      Just happened to find a Can-Am BRP dealer in town, so you know I had to check it out! They only had Outlanders, and some Jet skis, and you better believe they weren't cheap. I don't think that just over 28,000 USD for an Outlander is a good deal! After chatting with the sales people, they let me know that they had only sold two of the quads so far. They had no idea where someone could ride them and since there are not too many pickups or trailers, there is no way to get them from one place to another without hiring a rollback truck. Seems like a little too much trouble for me.

  • Similar Topics

    • By NathanFisk
      I have an 2003 Kodiak 400 Automatic and for some reason the starter not engaging I’ve replaced it still nothing it spins freely but not engaging. It was running fine the day before I am no expert so can someone please help me
    • By Susan Makowski-DeGraw
      My quad runs,  it starts up runs for about 10 minutes and then it dies if you let it sit for 10 minutes it’ll start back up ride for another 10 minutes and then die again, trying to figure out why it keeps stalling
    • By Randel1
      I'm having a problem getting a CDI unit that works. The parts list calls for a  4XE-85540-00-00 CDI unit. The one currently on the ATV works but there seems to be a problem with the spark advance curve. It will idle fine an rev. to about 1.5K then  starts bogging down sputtering, popping and basically running poorly. If you can get it above 2200 RPM it runs better. I have ordered and returned about 5 replacement modules that will not work at all. The unit currently on the bike has no part numbers or identification other than a Mitisibuchi logo. I am wondering if anyone else has experienced similar problems with replacement CDI's and if so what is the fix? So far I have not found a replacement CDI that will supply an pulse to the Ignition coil.
    • By Metusela
      Hello everyone,
      I am new hope am welcomed.
    • By NoahJakavi
      Hello i have a linhai 300 of the 2004+- era. I had a cluch problem so we changed it. After changing it has a hard time to start going. When you pop it into gear and press the gas it barely drives but when it starts going about 20km/h it start driving well the acceleration is normal and everything do you have any idea of what could be the problem
  • Recently Browsing   0 members

    No registered users viewing this page.

  • Create New...