Synthetic in 2/stroke

[geebt48cc]

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?

 

[Dave C]

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

 

[geebt48cc]

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......

Glen

 

[Dave C]

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

 

[geebt48cc]

compression

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.

Glen

 

[Dave C]

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

 

[geebt48cc]

Picture of 28" Schwinn

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

 

[buzbikebklyn1]

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.
BBB

 

[Dave C]

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.
BBB

LOL!!

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

 

[geebt48cc]

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