So riding my 250 yesterday; 85 degrees, 78% humidity. Rode about 40 minutes. When I got back to my shop I noticed the first bend on the pipe was blueish and the rest of the pipe was really hot. I checked the plug color after the motor cooled down and I found it to be a real nice light brown, perfect burn. So my question is, if my jetting is right why did the motor get that hot? Yes I was riding hard, but I didn't think I was pushing it that hard. Any thoughts?
1976 250 MC5 Original Owner
1976 Penton 175 XC
Make sure your pipe isn't plugged up.
Ron Carbaugh
thanks Ron, pipe is clear...
Quotequote:Originally posted by firstturn
Make sure your pipe isn't plugged up.
Ron Carbaugh
1976 250 MC5 Original Owner
1976 Penton 175 XC
Check your timing.
Ron Carbaugh
Too far advanced, yes? My thoughts too.
Quotequote:Originally posted by firstturn
Check your timing.
Ron Carbaugh
1976 250 MC5 Original Owner
1976 Penton 175 XC
Is your head pipe sealed with high temp RTV at the cylinder exhaust manifold?
Mike
No. I have never sealed my 250 or 175 motors. I just slide the pipe into the slip joint of the exhaust manifold. Have done it that way since the bike was new.
Quotequote:Originally posted by Mike Rosso
Is your head pipe sealed with high temp RTV at the cylinder exhaust manifold?
Mike
1976 250 MC5 Original Owner
1976 Penton 175 XC
Retarded timing could cause exhaust header overheating (ignition firing closer to top dead center). Fuel still burning when exhaust port is open.
So, the piston is set at less than the standard 2.55 BTDC, right? I am going to check the timing this week. Thanks for the input.
Quotequote:Originally posted by Richard
Retarded timing could cause exhaust header overheating (ignition firing closer to top dead center). Fuel still burning when exhaust port is open.
1976 250 MC5 Original Owner
1976 Penton 175 XC