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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Fossil on September 21, 2012, 07:51:40 AM

Title: hesitation and no power???
Post by: Fossil on September 21, 2012, 07:51:40 AM

I have just finished changing the rubber connectors under throttle bodys, (they were cracked). Everything is back in place as it should be and when I rode it I still had a stumble, poor throttle response, and low power and no rpm above 5K. What's next??

Title: Re: hesitation and no power???
Post by: lhead on September 21, 2012, 07:59:35 AM

Change out the fuel filter.

Title: Re: hesitation and no power???
Post by: Fossil on September 21, 2012, 10:40:51 AM

The filter was(?) new but I never did take tank off and totally empty it,just let the pump push out what was in there. I'll get the old filter out and try to get a look at the fuel pump sock. NAPA should have a match for it. Thanks for the tip.

Title: Re: hesitation and no power???
Post by: Rick G on September 21, 2012, 07:48:54 PM

Make sure you have a good seal at the cylinder head junction. I have a friend here who had to try 3 or 4 times to get a seal and not for a lack of experience either.

Title: Re: hesitation and no power???
Post by: frankenduck on September 21, 2012, 08:03:31 PM

I assume you replaced them with new ones, correct?

Easy to test for leaks.  Spray some starter fluid on them at idle to see if that increases the idle.

Title: Re: hesitation and no power???
Post by: Fossil on September 21, 2012, 09:30:00 PM

I replaced the orings as well as the rubber sleeves. The propane thing helped me get started on this hesitation problem. Thanks 

Title: Re: hesitation and no power???
Post by: frankenduck on September 21, 2012, 09:38:45 PM

Have you done this yet?

Renewing Heat Sink Compound on Ignition Module (http://www.motobrick.com/index.php/topic,3061.0.html)

It's one of the most overlooked maintenance tasks on the early 4Vs and causes the exact symptoms you describe.

Title: Re: hesitation and no power???
Post by: Fossil on September 22, 2012, 12:30:30 PM

I'm hoping that the fuel filter change and a very clean tank will solve the problem. I know about the ign module fix, but this hesitation comes on so quickly that the module can't heat up that fast,,,,,can it??? 

Title: Re: hesitation and no power???
Post by: frankenduck on September 22, 2012, 01:03:56 PM

You want to replace the heat sink compound anyhow as regular maintenance and its a simple inexpensive task.  It certainly won't hurt.