Questions about hot days and about engine braking

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Ironhorse5.1

New Member
May 11, 2014
20
0
1
Norman, Oklahoma
I have a rear mounted friction drive using the Tanaka PF-4000. I read that one con of a 2-stroke engine is that they're not good for long rides on hot days. Where I live the summer temps get to be around 100F. I thought I read somewhere that the engine is forced cooled by the fins on the fly wheel. So would that help it any in hot weather as opposed to engines that rely on ambient air around the cylinder head?

Next I read that engine braking is bad because of oil starvation during closed throttle at high RPM. When I release my throttle from speeds of 25-30 MPH the centrifugal clutch doesn't release until around 18 MPH or slower. So I notice the engine actually slows the bike until that point. Should there be any concern and maybe take caution to slowly release the throttle to that point when possible?

Sorry in advance if these are silly questions. Thanks.
 

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
I cannot speak for the Tanaka as I have no experance with one. I have been running 49cc Morini's tho. My clutches have always had engine braking to them. Some clutches set ups were even better in the dirt for traction for certain riders. Smaller than me lol.

About 20,000 miles coming up on one motor. 14,000 mile tear down inspection showed cross hatch still intact in the bore.

Had carbon to scrape out of the exhaust port. prolly 10% blocked or more, don't remmember.

I run good oil and jetted for it. Most important thing to do IMO.


They say not to clutch these Chinese two strokes in going down hills. I kind of agree there.

I tend to mix my throttle up tho when riding as I think I'am oiling better if that makes any sense?
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
22
0
memphis Tn
Any premix oiled engine should not be used as engine braking with throttle closed. Simple common sense. Closed throttle=little lubrication+engine braking=potential damage and/or wear.
But consider MX bikes: They need no special riding style to prevent damage...it all evens out unless you ride multi-mile downhills and are brakeophobic.
But your specific case is different because you have no control of clutch engagement so there's not much you can really do.
I doubt the rpms you mention are going to kill it.