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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

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.

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.