Big Gun Rev Box

2 replies to this topic
  • motodawg

Posted February 18, 2005 - 03:21 PM


Just slapped a Big Gun Rev Box into the 450 and it does make a noticeable difference in overall performance. In fact, I'm not sure the beast really needs that much HP. What am I saying? Anyway, being the only thing that I changed, and BG not providing any tuning/jetting/whatever tips (nada) with the unit, I'd have to say that installing the Rev Box has made it extremely difficult to start. Like they bumped the initial advance a little too far? Warm or cold, fast kick/slow kick, full kick/short kick. It just won't start until your leg is about to fall off. Any suggestions? :)

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed

Posted February 18, 2005 - 08:00 PM


Hmm...maybe its not the Rev Box? How are you sure?


  • motodawg

Posted February 18, 2005 - 09:47 PM


In this instance, it was the only thing I changed. Previously, the 450F was the easier starting bike of our 250F/450F pair. If it's above 50 degrees I could pull the "choke", wick it twice, bring'er up to TDC and fire it in one swift kick. The only other time it was this hard to start was the last arenacross we were at. It was below freezing all day and if it sat too long I had to give it a shot of fuel for every kick until it fired. The cold had taken it way lean.
This time though, I tried all the cold start tricks I know and it wasn't until I pulled the hot start and aired it out a bit that it acted like it might start.
I remember from the muscle car era that when we would physically advance the timing on car engines by rotating the distributor, if you advanced it too far it was hard to start. It might run good at full throttle, but starting it was a pain. Conversely, if you retarded the timing it would start easy, but not run to it's full potential. Anyway, it reminded me of the advanced timing problem.

Related Content


Megabomb Fitment by 288yz450

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info

  • 0 replies

James Stewart back on a YZ450F by YamaLink

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies

YZ450F 03 Sparks driving me crazy by SirAttard

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 5 replies

Michigan Motocross Tires by 288yz450

Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.