M900 dry plugs no start- Success

Started by beethoven, March 06, 2014, 09:46:43 PM

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beethoven

Hi
Went to start my usually reliable Monster today and no go. Been sitting for 3 weeks, nothing dramatic. Ran strongly last ride and no signs of lameness. Cranked strongly. Checked plugs and they were both dry as! Both cylinders not getting fuel. Checked fuel and added extra just in case. Still no go.
Pulled carby line off vacuum pump and cranked. Fuel pumped out of pump outlet. Blew through rubber hose to carbies. No blockage and could hear it in carbies.
Put fuel into carb bodies and started and ran til fuel exhausted. Repeated three times to see if this would pull fuel through. Always died after using dumped fuel.
What is left.
Any suggestions
Thanks for any feedback.

Al
97_M900                                                     07_Triumph_Sprint

Speeddog

Try bypassing the vacuum petcock.
I've got a carbie M900 in that would run for a while, but then die.
Vacuum petcock would work OK to begin with, but eventually pinch off the fuel.

If that's the culprit, install a manual in-line petcock so a bit of debris in a float valve doesn't fill your cases with fuel.
- - - - - Valley Desmo Service - - - - -
Reseda, CA

(951) 640-8908


~~~ "We've rearranged the deck chairs, refilled the champagne glasses, and the band sounds great. This is fine." - Alberto Puig ~~~

beethoven

#2
Thanks for this. I have ordered a Motion Pro petcock as I have always thought this a good idea regardless.


Regards, Al
97_M900                                                     07_Triumph_Sprint

seanster

I'm interested to hear more too bc my m900 would not start either and plugs are dry. I can see that fuel are I'm the bowls but somehow doesn't get to the heads.
2001 Supersport 900 Yellow!!! (she's just so much fun)
2000 Monster 750 Carb Dark!!! (Sold and still full of regrets)

Speeddog

Try a direct gravity fuel feed to the carbs, see if it'll run that way.

You can open the float bowl drains to confirm they're getting fuel.
- - - - - Valley Desmo Service - - - - -
Reseda, CA

(951) 640-8908


~~~ "We've rearranged the deck chairs, refilled the champagne glasses, and the band sounds great. This is fine." - Alberto Puig ~~~

seanster

Quote from: Speeddog on March 07, 2014, 09:57:01 AM
Try a direct gravity fuel feed to the carbs, see if it'll run that way.

You can open the float bowl drains to confirm they're getting fuel.

Speeddog,  I did direct feed from the tank to the carbs (with only fuel filter and manual petcock in-line)  and open the drain screws to confirm that there are fuels in the bowl.

I did this:  I drop a little bit of fuels into the air intakes and tried to start the bike....it did try to catch though.  Some how the fuel is not passing the carbs to the engine?  I cleaned the carbs and install new jets with factory pro kit.


@OP - sorry I didn't mean to thread jack.
2001 Supersport 900 Yellow!!! (she's just so much fun)
2000 Monster 750 Carb Dark!!! (Sold and still full of regrets)

Speeddog

When you cleaned the carbs, did you physically remove and visually confirm that the pilot jets were not plugged?
- - - - - Valley Desmo Service - - - - -
Reseda, CA

(951) 640-8908


~~~ "We've rearranged the deck chairs, refilled the champagne glasses, and the band sounds great. This is fine." - Alberto Puig ~~~

beethoven

Well I got time today to check system again. As suggested by Speeddog I bypassed the vacuum shut off and the bike fired up immediately. Just waiting for Motion Pro petcock delivery to install.

Thanks Speeddog

Al
97_M900                                                     07_Triumph_Sprint

seanster

Quote from: Speeddog on March 07, 2014, 01:12:35 PM
When you cleaned the carbs, did you physically remove and visually confirm that the pilot jets were not plugged?

yes i did...i even use a small electrical wire and feed it though the holes and such to really making sure that it was not clogged.
2001 Supersport 900 Yellow!!! (she's just so much fun)
2000 Monster 750 Carb Dark!!! (Sold and still full of regrets)