Heat problem fixed!

Jamesmx5

Joined
Jun 28, 2006
Messages
14
Location
Ohio
A few weeks ago I attended a tech day in the Indianapolis area. Tons of thanks to Bill for his expert help on doing a throttle body sync, my bike not only runs better than new, there is MUCH LESS heat radiating off of the bike. Bill pointed out that my pipes were discolored from the heat caused by improper throttle body adjustment. I never would have guessed it could cure the heat problem. My '03 was an oven before. You would not want to touch the sides of the bike after a long ride. The storage pockets would get too hot for me to leave my cell phone or anything like that in them. I can't say the bike doesn't put out any heat anymore, but even after a long ride in 75 degree weather with long pants on and my usual boots, I could feel a difference.

I highly recommend this before you wrap headers and so on. I was ready to wrap my headers and install heat shielding on the body panels. There is no need to do that now thanks to Bill!!!

I am one happy :03biker:
 
I have heard these claims before and have no doubt the perception of less heat is there but can't understand the mechanics behind it but would like to.

As I understand it, the role of the starter valves in the fuel injection system is to allow adjustment of the point at which the throttle bodies begin to open which allow more air/fuel mixture into the cylinders. They do not lean or richen the fuel/air mixture by themselves or change the fuel mapping program which is PGMFI computer controlled and set at the factory. If the three starter valves are adjusted to match #1 then all cylinders are pulling the same amount of vacuum at idle and theoretically all opening at the same time and providing the smoothest increase of power as the throttle is opened. Equal vacuum at idle ensures each injector is metering the same amount of fuel into each cylinder and the four throttle bodies are "synchronized" to open as one.

It is well known that leaning a fuel/air mixture causes a rise in exhaust gas temperature up to a point but the starter valve settings and the act of synchronizing the throttle bodies does not change the fuel/air mixture at all, so how can doing this affect the amount of heat coming off the exhaust headers?

I hope that someone with a deeper or better understanding of Honda's PGMFI fuel injection system can explain this to me.
 
I really can't explain it either. What is evident is that the pipes on bikes that have good throttle body sync are not changing color like the pipes on my bike were. My pipes looked yellow/tan and would discolor quickly even after I polished them. There was also a difference in header temperature when measured on a bike with good adjustment vs. my bike. Another thing I can't explain but I did hear for myself was that there is a difference in exhaust tone at idle of a bike that is adjusted vs. one that has not been. The tuned bike had a deeper sound when heard running side by side with an untuned bike.
 
IT'S TRUE, IT'S TRUE!!! I agree with James. I also attended the tech day and had Bill also did the throttle body adjustment on mine. I took mine out the next day and did 325 miles and the temp. reached 80 degrees that day. To say there was no heat would be a lie, as every bike is going to put off some heat, but it was like a different bike. Glad I had my done! I don't know all the mechanics of it all but maybe we can get Bill to chime in and explain it.

Also why doing the adjustment we found that mice had got in my air filter and built a nest. No damage to wires on anything else on the bike, just looks like they built a home and left the rest alone.

I would suggest doing the Throttle body adjustment before spending any money on other fixes!

Landon
 
SO theoretically mice in the air box can cause increased engine temps??? lol :rolleyes:

No seriously,

interesring post. . . I see the pipes on my new '06 are discoloring badly.
sort of a purple /bronze color? is this normal?

I have not noticed any real heat problem yet but have only ridden in cool weather when any extra heat is welcome.
 
2dogs said:
SO theoretically mice in the air box can cause increased engine temps??? lol :rolleyes:

No seriously,

interesring post. . . I see the pipes on my new '06 are discoloring badly.
sort of a purple /bronze color? is this normal?

I have not noticed any real heat problem yet but have only ridden in cool weather when any extra heat is welcome.
Click to expand...

Yes, The mice in the air filter did increase the temp. The mice did not cause it from day one though. My pipes were severly discolored! I just took them off and polished them up so we will see what happens now. I would really recommend doing this adjustment first.

Landon
 
Interestingly enough though the bike that had been adjusted did not have discolored pipes. It goes back to not leaving the choke on with a carb bike because it will discolor the pipes near the headers. This is apparently doing the same thing, as running too lean or rich so it discolors the pipes much quicker.

I still have to polish my pipes after having the throttle body sync but it will be interesting to see how long they stay looking good. As it was they would turn tan and discolor after one ride if it was a longer ride.
 
This does seem to coincide with the differing opinions of a "heat issue" on the ST.

I've never really felt it to be "too much", even in Florida weather. But I dont go down town and sit at traffic lights on 100+ degree days either.

Have almost 14k miles on mine, have cleaned / polished the pipes maybe a total of 5 times. Never off the bike and always just at that one point of the juncture of the pipe and muffler. Usually take about 10 or 15 mins ea time.

And I've never sync'd the starter valves, but I do have a Carb Tune II ready if it runs / looks like it's needed.

Interesting,
 
John,

To answer your question, I'm sure a good mechanic can do it. However, what you need is a good PATIENT mechanic. It took Bill at least an hour to get mine sync'd...and I understand that the tolerance is much larger than what we were trying to achieve. Bill not only tuned it at idle, he also took the time to work on it at the typical operating RPM's so the bike is smooth at the RPM's it normally cruises at. He built his own manometer that is more sensitive than what store-bought versions are...especially those with mercury. The job itself is not hard at all, you don't even have to take the side panels off. It requires raising the gas tank, removing the air box, and that gives you access to everything you need. Taking the time to adjust everything perfectly takes more time than it does to take it all apart.
 
Cash in hand looking at an 05 w/ ABS this weekend. The heat thing scares me, a little. Sold my 93 ST 1100 about a month ago. It got hot but I could live with it. Has anyone tried Jet Coating / Ceramic coating the pipes?
 
Mikeysduck said:
Cash in hand looking at an 05 w/ ABS this weekend. The heat thing scares me, a little. Sold my 93 ST 1100 about a month ago. It got hot but I could live with it. Has anyone tried Jet Coating / Ceramic coating the pipes?
Click to expand...

Mikeysduck,

Chris has the 1300, I have the 1100...
We've ridden all around Pearblossom on them.
They're both hot... 1100+cc between your legs...

Don't sweat the heat.
Mark
 
You must log in or register to reply here.
Top Bottom