15 mile round trip too much for new build?

GoldenMotor.com

sneekypete

New Member
Oct 22, 2015
16
0
0
Lawrence KS
I have a PK80 motor in a schwinn legacy, on its second tank of break in gas (5oz of mix per gallon).. I've put a New fuel line in it, NGK B6HS spark plug, and New muffler gasket.. I wanted to take it into town this afternoon, but wasn't sure if it was too early in the break-in process for a trip that far. Mostly flat, paved terrain the entire distance.. I'm 230 lbs, not sure the elevation but I'm in Lawrence KS... Any help or suggestions would be appreciated!!!
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
No problem. Check stuff for tightness once you get there.

Be sure to vary throttle and speed.

Perfect for a break-in run.
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
Ditto: You don't want to abuse the engine but there's no need to baby it either. Let it wind out a few times but just don't hold it there for too long. 15 to 20 second bursts will suffice alternating with some half throttle cruising. Your engine will love you for it.

But as Joe said; check the critical things for tightness, especially fenders if you have them. Engine mounts, intake and exhaust manifolds, (don't over tighten them) axle nuts, steering gear etc. You'll be good.

Report back and let us know how your first solo cruise went.

Tom
 

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
bummer, was busy today - too late now to mention to look at how many fins of motor are showing on each side of frame as you look down, so you'll spot right away if it starts to lean left (as new builds sometimes do)
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
264
63
living the dream in southern california
If it's a round trip, that means you're stopping halfway, right? That's nothing for these motors.

I put a brand new engine on and rode it flat out about 70 miles one way to a motorcycle show, hung out all day, then flat out all the way home with no problems.

(You're experience may vary... :) )
 

sneekypete

New Member
Oct 22, 2015
16
0
0
Lawrence KS
Ok, just got back from my cruise.. Aside from me pedaling and separating the wires once, the motor performed excellent!! I let the bike reach top speed about 5-6 times on the open road to town.. It seemed to run smoother on the way back, with even acceleration and sustained pull from the motor without bogging down.. I'd guess that I cruised it about an average of 15-20 mph and topping out at 25-28 mph... Over all I'm pleased with it's performance, but throttle response still seems a bit slow with some bogging during re-acceleration.. Any tips or adjustment suggestions appreciated.. Also, I moved the float pin in the carb to the last setting on the c-clip before the trip-- after which the bike was able to idle without me giving it gas...
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
The Chinese 2 stroke will perform better with some miles under its belt. Don't worry too much about tuning or top speed until you have a couple of hundred miles on the engine.
You'll notice an increase in performance as the miles build.

This is because the rings are seating and the compression goes up. I'd leave the 'C' clip in the second from the top position until you've put some miles on. Even after that the second groove from the top seems to be about the right place.

Later you might want to experiment with main jet size but leave that until later. There is a lot of information here on carburetor tuning, soldering jets, replacing them with smaller ones, etc. But you shouldn't worry about that for now.
Congratulations on your first two way cruise. That's always a fun time when you realize you've done it on a bike you've built for yourself.

Have fun and ride safe.

Tom
 
Aug 26, 2015
472
6
18
Overgaard AZ
Never gave my motor a chance to argue. I live 15 miles from town. Fifty miles from work. Read my review for more info on that.

After a few hundred miles start tuning, till then, just check everything.

Watch your rag joint, I replaced the bolts with grade 10s, the nuts with grade 8 nylocks, and double up on the lock washers. Put one under the head of the bolt, and the usual one under the nut. I did this, and haven't had to retighten since, although I check before every ride. Before, I had to retighten every 10 miles or so, just to keep the sprocket straight.