We got the 4wheeler from someone that said the infamous line "It was running fine and just stopped" We got it for $100. Most of the wiring has been removed, enough was left behind that was required for the atv to run. The only thing still working is the kill switch. Anyhow, we got the thing running just fine the other night after putting gas into the carb and starting it. Anyhow, while I was putting the skin back on, I accidentally put the battery terminals on backwards. They were on there for a solid 3 mins before I realized there was slight smoke coming from the stator cover. I immedietely realized I put the terminals on wrong and took them off. I put them back on normally, and she started right up with no problems. We drove the atv for about 2 hours and it was running perfect. Then all of sudden she cut out in the middle of riding it and now it won't start back up. Does that stator on these atvs give trigger spark for the coil or however it works? Or does the stator only charge the battery on these atvs? Would it cause it not to start at all? Not even try to start? I tested for spark and we still get a good spark from the boot and from the spark plug when putting in near engine block. We took apart the carb completely and cleaned all the jets as well. No difference. It won't even start when putting gas directly into the carb with a spray bottle. CDI seems to be ok after going through some tests I found on this site. Kill switch still working after doing continuity test on switch. Im at a loss for what it could be. Its getting fuel "me putting it in", and its getting spark.. This thing should start right up! ugh

Any help will be greatly appreciated.

 

Update - Even tho we had a decent spark on the cylinder block, we went ahead and went a bought a brand new spark plug and put it in. It fired right up. We rode it ALL night for about 4 hours with no issues.

Put the 4wheeler in the garage and the next morning it wouldn't start. I went and bought another spark plug to see if that was the cause, but it wasn't this time.

However, now while cranking over I can hear/feel air pumping from where the cylinder connects to the other piece. Basically if you are looking at the spark plug, the air is coming from the left side of the head. Is that the head gasket? I feel like we blew it while riding it last night. I thought we was good to go!

 

So I realized it is indeed the head gasket. So I will be ordering a gasket kit to replace them.

Main questions

Does the engine have to come off to replace the head gasket?

Is there anything special I need to do before tearing it apart ex Bringing it to TDC etc?

Will the timing be ok?

Anything else anyone can think of while doing this job? Thanks!

 

I shall be crossing my fingers and digging into it tonight. Wish me luck! haha

 

So I answered most of my own questions. Motor is torn down and I got it TDC with both marks. From what I see, as long as those lines stay there.. ill be fine during the job.

Surprised I'm not getting any help here, but ill try again.

Question is, should I use gasket sealant on the head gasket? Or put it on how it is? THanks!

 

I have done both. There is a copper/gold head gasket spray or just dry. Either way worked for me. If you think you'll be rebuilding it again at some point, I would go dry.

 

Thanks for the reply! I MIGHT have to tear it down again later on, so I will install it dry just in case. It comes with a red line/seal already around it, so I was thinking it would be fine as well.

Another question if possible. I am worried that the starting problem might not be head gasket related. I have seen videos of quads running with blown head gaskets. Is it possible that a blown head gasket will cause no starting issue? Quite a bit of air blows out from around one side of the gasket. Thanks in advance!

 

Do a compression check. I can't remember the min psi, but I think below 80 it will no starty.

 

Yea it blows out all of the air on compression stroke, so that answered my question.

Last question and I will be set.

I am unable to find the timing mark near the flywheel. I see the T on it, but see no mark in the casing to line the T up with. I do see the timing groove behind the cam cover.

All the videos I've watched, there was a groove in the casing. Mine seems to be missing that.. or am I missing something?

Thanks in advance!

 

So the crankshaft has been turned both clock wise and counter clockwise while I was trying to find TDC. When the piston is at the top "looking through spark plug hole", the mark on the cam sprocket isn't lining up.

I need an expert in timing these quads. It's very hard when there is no timing mark on the flywheel side of the case.