Recommended Spark Plugs

Discussion in '2-Stroke Engines' started by gearhead222, Jan 8, 2010.

  1. gearhead222

    gearhead222 Member

    Dear Fellow Members-I have a Grubbee 2 stroke 48cc engine and am wondering what brand and type of spark plug you members recommend. I have a spare Chinese 4 x1.25 metric plug, but understand that there are better ones out there. Also, what is the recommended gap? BTW, GREAT forum! Thanx for any info:)-Gearhead
     

  2. CaptJ

    CaptJ Member

    Welcome gearhead222, I have a Grubbee 2 stroke 48cc from bicycle-engines. I live in CA and wanted to keep it legal (Slant 48cc). I just orderd 2 spark plug from Sick Bike Parts dot com
    #1 was NGK B5HS for cold weather #2 NGK B6HS for CA. The new plugs didn't fit. I had to remove the head and rind down the three center fins to clear the plug. Good luck and have fun. :D
     
  3. gearhead222

    gearhead222 Member

    Thanx Capt. J! Do you mean that both plugs you ordered from Sick Bike parts would not fit without modification to the head? Did you have to grind the cooling fins to use your spark plug socket? Do you or any of you members know if the NGK BPM7A or BPM6A they sell would work better without any head modification? Thanx for any specific details from anyone:)-Gearhead
     
    Last edited: Jan 8, 2010
  4. Pablo

    Pablo Motored Bikes Sponsor

    I never heard of any head needing grinding on the fins to accept an NGK plug. Interesting to know. I'm assuming the wrench hits or something?
     
  5. CaptJ

    CaptJ Member

    Yep! My regular long spark plug socket 13/16 hit the three center fins on rear of the motor carb side. Very easy to do just remove top nuts (notice how tight the nuts are then put them back same way) I don't have torque wench I think it's 12 lbs. I used a rotary tool with a stone. I cleaned the head with carb cleaner total clean. I oiled the spark hole with 3 in oil. After assembly I had a 20 minute ride, up to 25 mph for 2 minutes.
    I'm on my first tank of gas.

    Have Fun Yall
     
    Last edited: Jan 8, 2010
  6. our kits come with a sparkplug remover and fits just fine with the plugs.
     
  7. CaptJ

    CaptJ Member

    Pablo, the thin wrench that came with kit will work but it's hard to fit around the plug. On my engine I had to tap down the (kit) wrench with a hammer. After the (kit) wrench is barely on, it's hard to remove. For me using my USA long spark plug socket after the grinding makes life easier. :D
     
  8. AussieSteve

    AussieSteve Active Member

    Most kits come with a plug socket, but they're absolute c r a p.
    A B5HS or B6HS are still the best plug choice for these engines.
    If you have to grind the fins a bit to use a decent plug socket, so be it, I reckon.
    Throw away those (rubbish) stock plugs.

    Pablo, thanks for your help with my studs. Also, love the slimline air filters. They make the stock ones look like rubbish.
    Used one of your metal exhaust gaskets, too.
    First test ride with billet head, 3L tank, Sick Bike Parts air filter, 'O' ringed alloy inlet, Mountain Mirrycle mirror and VELO recreational seat tomorrow. (Done 370km, so I'll go from 16:1 to 20:1 oil, too, with 8ml/litre octane booster as before to suit the hi-comp head.)
    Should be fun.
    ... Steve
     
    Last edited: Jan 9, 2010
  9. AussieSteve

    AussieSteve Active Member

    I was gonna PM, Paul, (Pablo), but couldn't attach pics. (Plus I wanted others to see how decent vendors conduct themselves.) You guys have won me.
    The thread on the studs was beautiful. I fitted both flat and spring washers with a couple of mm to spare, just as it should be. Previously, even with just a flat washer, the nut wouldn't fully tighten down on the stud.
    Once again, thanks for the help.
    For anyone reading this, Sick Bike Parts are #1 for parts and service.

    ... Steve

    I posted this in another thread yesterday:-
    (I didn't screw the studs in too hard. They started to bind a bit before bottoming. Nothing wrong with the studs, I think there was a bit of loose metal in the bottom of the holes. Didn't want to strip anything. The nearest one protrudes the furthest, the others are about 1mm closer.)

    [​IMG]
     

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    Last edited: Jan 9, 2010
  10. Pablo

    Pablo Motored Bikes Sponsor

    When I get some free wrench time, I'm ordering that head.

    NICE engine set-up.
     
  11. AussieSteve

    AussieSteve Active Member

    Thanks, Paul. And the heads do look good, don't they? I'll keep everyone posted on performance etc.
    After seeing EnFlamED's video here earlier, I wish I could add a SBP shift kit, but I need the bikes momentum to bump-start the engine, especially with the billet head. I couldn't pedal hard enough to turn it over otherwise. (50kg and bad lungs.)

    A couple more pics. I just changed the front engine mount to include the small curved black steel brace as shown, plus 2 x 1/8" and 1 x 1/16" layers of rubber to absorb vibration. This is an alloy frame, so the steel reinforcing brace is a must, otherwise the (high-tensile) bolt might pull through the wall of the tube, in time.
    For anyone without a decent exhaust bracket, this is one easy way to do it. Don't rely on the 2 x 6mm studs to hold the weight of the exhaust.
    I used 1mm aluminium.
    These pics also show where I added rubber blocks to the cylinder and head fins to stop ringing.
    I'm a bit ashamed of my handlebar view, see all of the junk, but I wouldn't do without any of it. (The speedo shows 218km, but I did 150km before it was fitted, total 368km.)

    ... Steve
     

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    Last edited by a moderator: Jan 9, 2010
  12. gearhead222

    gearhead222 Member

    Thanx for the feedback , guys! That head ROCKS! Really like the slim design air filter also. Is that a dry or wet filter? Kinda reminds of the K&N type-Gearhead
     
  13. AussieSteve

    AussieSteve Active Member

    Hello gearhead222, sorry for hijacking your thread. Couldn't help showing off the improvements. (The plug is a B5HS, though. I've alternated between that and the B6HS as I tuned the carb. The B5HS runs cleanest for me.)
    The filter is a dry element. Not sure what it's made of. Not paper. Really good flow and a beautiful fit. (No more leak at the base of the air filter. Also, my stock filter distorted when I did the screws up properly and leaked even more. In a dusty area.....)
    Pablo can probably tell you more about their construction. All I can say is that for $14US, they're well worth the effort.

    Do K&N still exist. I used to buy their stuff for my dirt bikes about 30 years ago. (Bultaco Matador 250, Bultaco Pursang 250 and for a while, a Bultaco Sherpa T 360. All had Mikuni carbs and K&N filters.)

    Yep, a European bike nut. My favourite was a GT850 Ducati. Almost bought a Ducati 'Monster' when they came out, but saw reason and abstained.

    ... Steve

    A pic of the B5HS after about 20km. Pre billet head etc.
    The greyish tint on the insulator is only the ceramic showing through, not a lean mix.:-
    [​IMG]
     

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    Last edited: Jan 9, 2010
  14. give me vtec

    give me vtec Active Member

    it is my experience that the plug doesn't make much difference. I guess I could say the engine feels a little smoother with the b6 or b5 ngk plug.... but it always feels stronger with the chinese plugs that come with the motor.
     
  15. AussieSteve

    AussieSteve Active Member

    Maybe you got a better quality plug with your kit. I tried mine for about 2 short rides. It ran too cold and oiled up quickly, especially with the run-in mix of 16:1. Even the B6HS ran a little dark, hence the B5HS.
    If nothing else, you can expect much better reliability with NGK.
    Not sure about the smoother/stronger bit.

    As an extra note, the stock plugs are every bit as high a quality as the rest of the kit. Ha, ha. I'd be suspicious of cracks in the insulators and other minor faults that might cause tracking etc. The more bits of these things that can be replaced by decent parts, the better. Some plugs might be good, but others.....

    ... Steve
     
    Last edited: Jan 9, 2010
  16. give me vtec

    give me vtec Active Member

    the ngk plugs are definitely better quality... no doubt. You're are right, the stock plugs are every bit as quality as the rest of the kit.

    I was just talking from a performance point of view.... what I feel in the seat of my pants if you know what i mean.
     
  17. CaptJ

    CaptJ Member

    QUOTE STEVE: For anyone reading this, Sick Bike Parts are #1 for parts and service.
    CaptJ will 2nd that! My last order took three days. Not to mention there new TEFLON COATED CLUTCH CABLE that I orderd.
    I waiting for a clutch roller from AL.Fisherman with the roller and teflon cable should be s-l-i-c-k.....
     
  18. AussieSteve

    AussieSteve Active Member

    Yep, Ron, (Al.Fisherman), is another one with his head screwed on right. Good choice.
    I've spent 3 months now, working out who to deal with and, possibly more importantly, who not to deal with.
    To improve your clutch still further, see this thread.

    ... Steve
     
  19. give me vtec

    give me vtec Active Member

    I will third that... every part I have gotten from sick bikes has been the best quality, fairly priced, and it always ships fast. The clutch roller from al is awesome... so worth every penny, you will love it. Dont even need the teflon cable, its that good.
     
  20. AussieSteve

    AussieSteve Active Member

    This stuff should really be in 'Parts and Accessories' or 'Vendor Reviews', but I'm sure that people get the idea. My SBP and RSE reviews are coming. (They may differ slightly.)

    ... Steve
     
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