Synthetic in 2/stroke

Discussion in '2-Stroke Engines' started by geebt48cc, Feb 25, 2011.

  1. geebt48cc

    geebt48cc Member

    Hey all,

    New 66cc slant after finishing thick 16:1 gallon of convintional. So, ran this total of two tanks at 70 miles.

    Ok, can I now follow all rules of breakin and running short rides, varying speed using Amsoil dominator synthetic 32:1?

    I've used from 70 to100 miles on the Amsoil 32:1, and plug looks clean + tan with good idle + power up hills.

    PS: After a few hundred miles on slant head , can I replace head gasket all together, using copper head sealant for a little more compression?

    What ya think?:confused:

  2. Dave C

    Dave C Member

    You could also do the sandpaper/sheet of glass thing and sand the head off. Some take it down to the flat, taking off about a milimeter or so. Pick up nearly a point of compression that way. I'd start with 120 wet/dry 3M paper. NAPA carries it. It comes in a pack of different grades if you look. I'd spray WD-40 on the paper, keeps it from clogging up and sand in a figure "8" pattern. Count like 10 figure 8's then quarter turn the head and 10 more, quarter turn and so on until you take off what you want. When your near being finished change to finer grits to make it smoother for a good seal.

    This is the cheap and dirty method for more compression. I instead got a Hi-Compression Puch head, paid $30 plus shipping. Ran into a problem with the head stud sizing in my block so I have to get a metric tap set at the begining of the month or I could tell you how well it works, or not ;)
  3. geebt48cc

    geebt48cc Member

    Thanks Dave........

    Dave, do you think it's really worth the trouble sanding the head one milimeter? Did it help your ht? How can you tell other than a compression gauge.

    Thanks for info......

  4. Dave C

    Dave C Member

    Up to a point on a two stroke more compression makes more horsepower and better utilizes any other mods you have done.

    I have a 151 Pontiac 4 banger that's full race. It started at a 8:1 compression ratio and about 80 HP. It now has 12.5:1 compression ratio and about 240 HP. Dropping the compression on this motor would mean a loss of about 100 HP if returned to stock.

    Your stock compression is very low, only 6:1. ANYTHIng is better than that. The seeming slight amount removed will help quite a bit in improving HP. You have to remember your removing material from the widest point of the head. I can easily see an improvement of 1 to maybe 1.5 points in the CR, like 7-7.5:1 CR.

    I think that's worth the effort ;)
  5. geebt48cc

    geebt48cc Member


    Wow, sounds good.

    Dave, ok, should I just sand off 1 milimeter off bottom of head? Can I sand any more? Don't want it to cause premature ware out on everything else do to upping compression?

    It's got SBP expansion chamber,NGK plug and wire,and free flow filter.

    .......but, one would think that upping compression word really help.

  6. Dave C

    Dave C Member

    From what I have been able to gather you can take it down to the cooling fin. Just keep the area cut down flat. No rocking of the head while you do it. The action is really kinda brainless once you get a pattern going, you could prob watch TV while doing it:D
  7. geebt48cc

    geebt48cc Member

    Picture of 28" Schwinn

    Not best pictures..........

    Attached Files:

  8. buzbikebklyn1

    buzbikebklyn1 New Member

    I've tried that "quick n dirty" of raising the compression, it works.
    It MIGHT be better to bring it to a machine shop for milling, but the method described works just as well.
    The bike looks good to me, I like the black n white motif.
    But then again im a retired Highway Patrolman.
    Great looking ride.
    Last edited: Feb 27, 2011
  9. Dave C

    Dave C Member


    I do have to agree, that bike does look good.
  10. geebt48cc

    geebt48cc Member

    Hey gang,

    16:1 conventional when new for first 70miles, then 32:1 synthetic Amsoil to now 125 miles. Here's the plug chop................NGK B5

    Attached Files:

  11. geebt48cc

    geebt48cc Member

    Problems with CNS

    Dave, I'll make or send some better pictures, but this is top of 2010 Skyhawk CNS carb. I think that there are different versions of this carb. There's one clear tube line that comes out of bottom of this Skyhawk CNS carb, but you can see here that there isn't any other place to mount it to anything?

    Like I said, this is poor pic, but there isn't any place to mount that one vent line to top of CNS like you mentioned? lol, you can see where I've done everything to stop any air leaks also.....


    Attached Files:

  12. Dave C

    Dave C Member

    Yep, mine's different. I have a Wabron from Boy Go Fast. It has the clear plastic from the bottom of the carb to a barbed vent up by the two cables. This is a fuel transfer for the choke. There would have to be a internal transfer passage to take it's place.

    Not suprizing there's multipul models of the same basic build.
  13. geebt48cc

    geebt48cc Member

    CNS- want to be!~

    Yeah, I'm not at all surprised. But hey, this older speed carb on the new 66cc is doing well. After milling head, it's doing great. Dave, I just might do the Puch head as well in a few hundred more miles.

    I'm going to get some new tires in 700X40 28". I was wishing in white wall in semi slick. Any ideas?
  14. Dave C

    Dave C Member