Decompression lever stuck?

7 replies to this topic
  • dezurist

Posted January 17, 2008 - 10:52 AM


Hey guys,

Long time lurker, first time poster.
I have a 04 YZ450F and upon my last ride this past fall, I go to start it one last time and I grab the decompression lever and its stuck? We were riding on a fairly muddy trail system all day and I just figured it had some gravel in the lever hinge area. After a thorough pressure wash it appears to be still stuck and I cannot depress the lever at all?

Any ideas?
Been riding for many years, but pretty green to the 4 stroke world.

Thanks for any help or suggestions.

~I accidently posted this in the WR forum.

  • King_Air

Posted January 17, 2008 - 11:15 AM


Well, we will need more information. A 04 YZ450 did not have a decompression lever. It had auto-decompresssion via the exhaust cam. Please confirm year/model of your bike.

  • William1

Posted January 17, 2008 - 11:58 AM


I think he meant the hot start lever.

By hand, disconnect it from the carb and pull the plunger out. Confirm the cable moves smoothly. If not.lean and lube the cable, disassemble the lever and clean. If the lever and cable is OK, the plunger is gunked up. Use contact cleaner, clean the plunger and carefully clean inside the plunger bore on the carb (use Q-Tips.)

  • dezurist

Posted January 17, 2008 - 12:11 PM



I bought the bike used and it has a after market lever right next to the clutch lever (just under the kill switch). I assumed that this is what it was.

Is this the "hot start" lever?

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • William1

Posted January 17, 2008 - 01:28 PM


Trace the cable. If it goes to the carb, it is a hot start, if it goes to the head, it is a ceomp.

  • grayracer513

Posted January 17, 2008 - 01:44 PM


It's a hot start. No YZ450 ever had a decomp cable. Pull the tank and pull the plunger out of the carb as instructed above.

  • dezurist

Posted January 17, 2008 - 01:51 PM


Thanks guys,
Looks like I got something to do this weekend afterall!
Minnesota forecast for this weekend looks like a high on Saturday of -3 degrees.:cool:

  • Wiz636

Posted January 17, 2008 - 04:05 PM


Use caution when threading the hot start nut back on the is a cheesy nylon nut and it strips out very easily. You can order an aluminum one from Zip Ty racing.

I put a very light coat of grease on my hot start plunger when I reassemble it to help keep it lubed.

Related Content


Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies

Chubby dad, looking at bikes , First trip to the orange/black forum ! by Slow_ride

Dirt Bike   Make / Model Specific   KTM   250-530 EXC/MXC/SXC/XC-W/XCR-W (4-Strokes)
  • Hot  28 replies

2016 YZ450 by CaptainKnobby

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies

yz400f throttle bog by yz400fmaniac

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • * * * * *
  • Hot  28 replies

100 hrs on 2014 yz450f, shim valves or replace them? by ttr230rider6

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  79 replies

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.