Honda vf500 engine question

[coasterrob]

I have a 1986 Honda Vf500 Interceptor. The engine has some issues and i would like to change it. Will a 1984 Honda Magna vf500 engine fit on the 86 bike? The engines look identical, but i am curious if the pipes and the carbs will fit on the 84 engine.

[ddeford]

I've been wondering the same thing. I'm sure someone here will know.

[tjwor]

i'm about 90% sure that they will work... the only change between vf500f from 84 to 86 were the heads, the magna engines are slightly different but as long as you aren't trying to interchange main parts from the 86 into the 84 it should mount up in the bike fine.

[coasterrob]

Its really stupid but here is the problem. The 86 engine runs perfect and has about 23,000 miles on it. The problem is overheating caused by slow coolant flow. I have replaced the water pump and the original pump turned out to be ok. I had all of the head gaskets replaced. The pipes were replaced because the pipes on the bike were rusted through. The pipes were Vance& Hines, replaced with Supertrapp pipes. I got several thermostats to check the problem. The cooling system was checked for blockage and flushed. The coolant was changed and replaced with Honda coolant. I got a used radiator that was 100% clean and installed that. The fan runs all the time when the bike is on. I wired it to do that. The sparkplugs were replaced with the numbers listed in the clymer rebuild book. Most of the rubber hoses were replaced. My regular mechanic told me to try it without the thermostat, with no change. He came up with the idea that it is not moving coolant like it should be. I know it starts to run bad when the temp shows over 3/4 on the panel. I have also had it go that far when i was going through slow traffic in 36 degree weather. The only other thing i can say is there is a lower compression on the front left cylinder, but it was only off a little bit. Any ideas?

[tjwor]

If i remember right the problem with overheating often comes from valve problems. I'd say check the valve clearance and see if there is a problem there...

[loopsandlogic]

How could valves from the engine cause overheating problems with the water temp?

Cause I'm having the same problem in 65 degree weather and my bike sounds nice and quiet!!

Sorry to chime in....I'm about to start my own thread.

LL

[Vidar]

Add me to the list of weirdness with temperature. My 85 VF500 remains at normal temp if moving, but once I get into stop and go traffic, my gauge climbs to the 3/4 mark before the fan comes and and stays there. I am not sure if the 3/4 mark is normal for this model or of there are other things to address. I have flushed the coolant and I am going to buy an infrared thermometer today to verify what exactly the 3/4 mark is in degrees at the sensor/thermostat. It never boils over, but it always worries me. While flushing the coolant, I had it running at 3000 rpms while on the center stand in 58 degree evening weather. It still does the same thing. Any original 84-86 VF500 owners that can validate if this is stock behavior?

[harry.hastur]

+1 on hitting 3/4 on the thermo in traffic. The fans usually stop as soon as I start moving at a decent pace.

This is my first Interceptor ('86 VF500) and I just assumed this is normal behavior for this bike.

[Vidar]

Dont worry, its normal. I had the same concerns as well. See:

VF500 cooling issues/questions...