99superhawk_Dom

I have another question. I know im a needy b****. So after rebuilding the rear head one muffler gets hot (meaning you can't rest your hand on it, but the other side does not get hot (meaning i can rest my hand on the muffler). Shouldn't they be the same temp?

scottiemann

one side will be hotter then the other... just in the design of the thing

99superhawk_Dom

Ok thanks i thought that because of the crossover thing it would equal out. But im not sure how it works.

E.Marquez

Ive never hit mine with an IR temp gun, but I know both of mine get hot... the same temp? No idea.. but hot.

If you have a header not getting hot, you may be running on a single cylinder at times, under load, ... if it's just the exhaust can.. pffffttt, no idea....

7moore7

Here is the explanation that I've found most reasonable: The crossover and exhaust system are built in a way that when the bike is idling, most of the pressure flows out of the left side of the bike. The right side will still give pulses at low rpm/s but it won't heat up. After back pressure builds at higher rpm/s the exhaust will flow out of both sides evenly. You can tell this if you ride the bike around for a bit, both sides will be hot rather than just the left side.

99superhawk_Dom

Im going to check the headers with an ir gun tonight. I disconnected the front plug wire and it fired on just the rear cylinder which is the one i rebuilt the head on, and did the same for the front.they both fired and ran.

twist

the VTR is new to me but I do know that the front cylinder runs hotter than the rear. Same with most v twins. Harleys are really extreme since they are not liquid cooled. I never noticed it myself, both are usually hot, too hot to touch and at idle the pulse feels the same. Maybe I have a "special" VTR! HA!

7moore7

Headers should both be way too hot to touch, but the cans are what don't head up evenly at idle. That's actually another test you can do... put your hand near each of the headers and if both cylinders are firing, they will both be way to hot to touch. But what throws people off is if they warm their bike up or just dink around the block a couple of times the left can will be warm and the right can not so much. After a stretch on the highway it's much less noticeable.

And I always thought the front cylinder ran cooler on this bike (hence running a richer mix in the carb in the back to cool it down a bit). Reason being it is exposed to fresh cool air up front riding...

99superhawk_Dom

Thank for all the responses. This is not my first street bike, but is my first v-twin and the first street bike that i have opened the engine up like i had to. I've rebuilt dirt bike and car engines. Maybe i'm being paranoid/not trusting my work. (I mean it started right up after i replaced the valves and put the head on! How often does that happen.) I just never noticed ot before.

I don't know much about superhawks, but if anyone has any technical questions about apple computers or apple wireless networking just ask.

Again thanks for all the help!

HRCA#1

I think you have that backwards the rear runs hotter hence the richer jetting.

Wicky

+1 Less direct airflow onto the rear cylinder