84 Vf1000f Power Loss When Warmed Up??

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mswarrior
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84 Vf1000f Power Loss When Warmed Up??

#1 Unread post by mswarrior »

Hi all, I need a little help on this one before I start throwing parts at it.

The bike is a 1984 VF1000F Interceptor with 45KM. The problem just started on a 2000 km trip I just took. What is happening is after the bike has been run for a while 5-30 min and I twist the throttle I get a throaty sound and no power and just yesterday while in the garage I started it up and warmed it up for 5 min and she backfired?

The oil is up, coolants are good, chain&tires in specs, k&n filter clean & oiled, battery fuids are up, new fuel filter, and I put 3 carb cleaning products in the fuel during the trip.

I have the official honda shop manual and I went through the trouble shooting. There is spark, yet the manual says the coils when tested with a multimeter should show a reading of 2.8 Ohms. When tested I get 000's on both coils which shows a short/no resistance, yet she starts up fine. The 1100 Sabre has the same coils so if anyone can test there own VF or Sabre and relay the reading it would be great.
I also whatched the fuel filter when warming it up and the delivery through it seemed a little intermitent. There was a air bubble in the filter and as fuel was going through it it seemed to flow in spurts which could be seen by the air bubble moving a bit in about 5 second intervals. Should it be a steady flow?

Any help would be great. Thanks in advance.

John
Many say live to ride, I say ride is to live.

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mswarrior
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#2 Unread post by mswarrior »

Unfortunatly it's not the spark unit. I let it idle in the garage for 10 min and all pipes did get hot. I also took out the #2 and #1 plug and put it in the plug wire and turned it over. There was spark and the plugs didn't seem that bad. There was a little oil on the threads though. I'm leaning towards a carb problem, any ideas?

EDIT: OK I took all 4 plugs out after another 10 min run and the front two are wet and the rear two are dry. There is spark at all plugs but I do not know if the front is getting enough?

The tach is reacting normal, no jumping in any way. I have noticed these last couple runs that the rpms are taking longer to come down after reving it up.
Many say live to ride, I say ride is to live.

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flynrider
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#3 Unread post by flynrider »

Most everything you've mentioned points to a lean condition. Backfire, no power when you twist the throttle (but normal idle), funky fuel flow and rpms taking longer to return to idle. If I had to guess, I'd say you have some sticky carb floats or a fuel line blockage. The bike runs normally when you start it, but as the floats empty, they don't seem to be getting replenished with enough fuel.
Bikin' John
'93 Honda CB750 Nighthawk

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