My Linhai 300 - Spark Plug Change
This is sort of going to be a 'How To' for Linhai 300 owners as I didn't find any of this info online when I sat down and searched for it. Thus this post can be added to serve those in the same position I was in when I went about what to do when I wanted to change the spark plug in my scooter. It isn't hard to do this by any means but having a how to around makes things more efficient in many ways. I have also included some other general info that I deemed to be helpful for future issues/projects.
Things you'll need
-Philips head screwdriver
(Remove the screws on the panels.)
-1 DR8EA spark plug
(Autozone. I bought 2 for under $10. Advance Auto in my area did not carry these.)
to properly gap the plug (Harbor Freight. The gap is .8mm)
-18mm deep socket
(Remove/install the spark plug. Harbor Freight.)
. I was able to use the tool set that came with my scooter. One tool can be used for removal/installing the plug.
Used to properly torque the spark plug. Not having this means you don't know what the plug (or anything else) is torqued at. I recently bought one from Amazon.com for about $25. I saw the same one at Harbor Freight for $5 bucks cheaper. I figured I got the same deal and paid shipping. Pittsburgh Pro was the name of the wrench. (Coincidentally I live in Pittsburgh, PA so this was strange and weird to me.) I never had a torque wrench before and got along just fine so don't think you need to rush out and grab this item if you don't have one. On the other hand I know every time I do something on this scooter that the important parts are torqued to the manufacturers specifications and this means that these parts are being used exactly like they are supposed to and makes me sleep better at night regarding my safety and my wallet. Tightening the hell out of a bolt that holds the wheel on to your scooter versus knowing that you tightened it to exactly what was the manufacturers recommendation are 2 very different realities. Also, after dealing with multiple instances of something wrenched down so tight and stripping screws and dealing with that because someone didn't know what torque to apply, this became a no brainer to buy. In the end it saves you time, money, aggravation and gives you safety, efficiency and piece of mind. Enough of my rant.
-Magnetic parts tray
. ($4 Harbor Freight)
This is a great optional tool imo. It keeps all your metallic screws and bolts together and stops them from rolling away and getting lost. It puts them all in one safe secure place and if you or someone else (your clumsy kid) or your excited dog (who has ADD) hits the tray, nothing happens vs. the dish or bowl or lid going flying and having to find all those pieces (hopefully). That or put them on the ground and hope you find them and don't lose them. It saves time and adds organization to the process and can be used on every project you undertake. Not having this I suppose you can use a bowl or cup or some other container to get just about the same advantages as having the magnetic tray. My days of not having this are over and I love it and the things it does for me. I'll be out riding on the scooter for that extra hour instead of looking for that screw, bolt, nut...know what I mean?
. I had no trouble seeing into where I needed to but your setup may be different. You actually may need one of these to see what you're doing. I bought a headlamp from Harbor Freight for under $5. This keeps things hands free. Just the way I want them when working on something.
Well enough of this and onto what I did to change the spark plug on my Linhai 300.
In summary this is going to be what you're going to do:
1. Remove 2 footpads on the right side of the scooter.
2. Remove screws attaching the lower panel and remove the lower panel.
3. Find the spark plug. Remove spark plug boot from spark plug.
4. Using either a socket set or your toolkit tool remove the spark plug. Gap new plug then install.
5. Put everything back together.
6. Test run.
Now onto the more detailed explanation:
1. Remove the 2 black footpads on the right side of the scooter.
This gives you access to the screws you'll need to remove the bottom panel, giving you access to the right side of the scooter engine. On mine there were 3 screws I had to remove to get this bottom panel to come out. It definitely looks like there were supposed to be more screws holding this on my scooter but those screws weren't there. They were either lost by the previous owner/mechanic that worked on it or they came out from riding. Something I'll have to replace and address. I didn't use Loctite on them but I think I will hit them up with some just to address this finding. So you may have more screws to remove than I did and I suggest dealing with the whole 'keeping the screws from vibrating loose' possibility.
2. Remove the lower panel. (See pic for screw locations)
(This next paragraph doesn't have anything to do with this project but if you didn't know where these things were exactly now you can see and take a look at where they are and what's involved in getting to them etc.)
Note in the above picture the location of the fuse box. I included a pic of the CDI (it shows 'Digital Igniter' 7500 printed on its cover). I also included a pic of the fuse box housing itself showing which fuses the Linhai 300 uses:
(2) 15 amps
(1) 7.5 amp
(1) 3 amp
3. Locate the spark plug.
It's not hard to locate so note how it looks in the picture and then look under where the lower panel would be and you'll see it. It sits back a little bit. Remove the plug boot from the spark plug.
4. Remove the spark plug.
Here I used my toolkit spark plug removal tool. I used this because there really isn't much room to work with and the tool is able to be inserted into that space rather easily. I then used the screwdriver from my scooter toolkit and put the screwdriver into the hole at the rear of the spark plug removal tool. This allowed me to use leverage to turn the tool to remove the spark plug. It wasn't wrenched in there too tight but I did have to give it some elbow grease to get it to 'crack' and loosen up for me. After it was loose I removed the plug by hand and inspected it. I'm no expert at reading these but I believe my spark plug to be in the 'perfect' category, the scooter is not running too lean or too rich. (Feel free to look at the pictures and comment your thoughts on this.)
Inspect the area the plug screws into and make sure everything looks ok. Remove any dirt etc. Open and inspect your replacement DR8EA spark plug. Everything looked ok on the replacement. Get your gauge tool and find the .8mm gauge. Insert this at the proper spot. Mine didn't fit. It was just barely tighter than the recommended .8mm gap. I didn't do anything fancy here. I stuck the gauge in there and pried it open slightly. Then tested it again. It was too wide. I put the gauge in the gap and pushed the top of it against my dresser and it closed the gap onto the gauge. The gauge fit perfectly. No damage was done to the electrode or the spark plug. Here is a link for how to gap a spark plug.
I screwed the new spark plug into the scooter and hand tightened it until I couldn't any more. I then put on the 18mm deep socket and set my torque wrench to 13 foot pounds. (The manual says 18 Newton Meters and that converts to 13 Foot Pounds.) It was a tight fit getting the socket into the small space and I was barely able to do it. Tightening it demanded 2 hands, 1 hand holding the socket and the other moving the torque wrench. Small increments were used to tighten it until it hit proper torque.