I have a Linhai 300 4 x 4 that has about 34 hrs running time on it, and I've had it for about 3 years. The problem is that it starts up fine and runs good for about a half hour or so then it shuts down. The engine will crank but will not start until it sits for about 45 minutes to an hour. I have replaced the stator, coil and regulator on it and it still reacts the same. Anybody out there with a similar problem or any suggestions? This machine has been a bad investment for me so far. I would like to get it going so we can use it.

 

after it runs for a while, then dies, and then you crank it, did it lose spark? have you checked for spark while it cranks after it has ran? just wondering if something is overheating and killing spark or if it may be a valve issue. does it die on its own after a 1/2 hr of riding? does it bog down slowly or just kills itself? are the handlebars in any particular position when it dies? (crossed wires scenario-short circuit?)
just thinking out loud.

 

I want to second all of Jaster's suggestions.

We really need to separate mechanical issues versus fuel issues versus electrical issues. So checking for spark during the 45 minutes or so after the quad quits that seems like the best test to do first. If you have spark during the recovery period after failure, and the quad still doesn't start after you put the plug back in, then we need to focus elsewhere than on electrical issues.

The long warm up time to failure, and the equally long cool down time to recovery suggests that the problem is connected to something thermally massive such as the engine (if this is heat related - which is a good first guess). Something small like a CDI or a regulator would heat/cool in a minute or so.

 

I have never really checked the spark between the cool off time because in the time it took me to tow it back it was always startable again. I'll run it and check the spark right after shut down

 

are you still using the "off brand" spark plug? if so, please take it to your local parts shop, autozone, O'Reilly's is satisfactory, and have them compare it and replace it with the NGK brand. it may not be a spark plug issue, BUT, for $3, it's a fairly cheap fix. now i'm not saying that this'll fix it right now, BUT, in the past, this has fixed several other quads. it is a step in the right direction. but please get back with us with detailed information concerning your test for spark after the shutdown has occurred.

 

HI guy's....have the same problem..
LINHAI 300, 4x4 , engine quits suddenly once it get hot enough for the cooling fans to come on.....
new NGK plug etc fitted...carb ultra sonically cleaned and rebuilt.....
once the engine quits, used a second spark plug to test for spark and with the ignition on the plug sparks twice per second with just the ignition on...once u crank the engine it sparks what I would say was about the correct amount/timing....
any idea's please...have seen similar problems on the sight but no answers....
I need this machine to round up sheep, I'm dead without it....
many thanks Frank clogs

 

Sparking without the engine turning seems wrong and would point to the CDI but always check the fuel cap vent first by loosening the cap when the fault comes on, a sucking sound and the ability to re-start right away, indicates a blocked tank vent.

 

Hi Thanks 4 the reply…..
actualy the tank was loosely fitted and no cap on at all……have fitted an in line fuel filter (see thru) and the carb prime's with fuel real quick….and whilst I was at it I flushed out the fuel tank and system with fresh fuel…..

tomorrow plan to check the electrical switch under the base of the carb (it has 2 wires) before I run it and then when it stops…not sure if it's a fuel solenoid valve…will check the earth to this valve at the same time…and perhaps after that if all's well I'll disconect the cooling fans for a min or two, perhaps they are robbing juice….
not sure if I said that the engine starts first hit of the button and runs sweet untill it get hot then just stops suddenly…..if u try to start it after the problem it just spits back thru the carb (the air filter is new and all fitted correctly) and the starter motor suffer's with the backfire (thru the carb) there is no backfire from the exhaust…….
the machine is as new…
probably 200 hours of running….still on original tyres, not even 1/2 worn…..
I live in a very rural area and there's no place to check any electronics….if anyone suggest electronic test to carry out please be easy on me, I'm no sparks….hahaha….
I don't even know where there is another machine that I can substitute parts with….

many thanks Clogs

 

Have u looked at the fuel line after this? Could be possible the line is boiling and causing a vapor lock and will not start till fuel cools down and trickles back to the bowl.

 

Hello
I have just joined this forum to fine an answer as to why my linhai quad 300 4x4 shuts down after 30 minutes and won't restart until at least 3 to 4 hours later.
Here is what I have done so far to check.
1.0 Before starting the engine I have checked that there is a spark
2.0 I run the engine until it shuts down - around 30 minutes.
3.0 I check for a spark - there is none
4.0 around 3 to 4 hours (long after the engine has cooled) the quad will restart

Any ideas?

thanks