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What can you tell me about my VF500?


Tyy

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I'm no expert. I'd be putting jetting back to standard just to start back in the beginning! Then you can play from there once engine is running smoothly. As Jeremy said, those may be too large? Too lean and engine will run hot (burn valves, like a cutting torch) and pop on deceleration, too rich and it'll blow sooty black smoke on hard acceleration(while also washing all your oil off the cylinder walls) and splutter on acceleration(probably as plugs get too wet then fire then get wet again).
Vacuum on petcock would be to slow and speed flow depending on demand from the engine, high rpm= high vacuum= pulling diaphragm against spring and allowing more flow.
If fueling checks out, I'd probably look at retarded ignition timing?

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We run the VF500F with open baffles and open airbox.. So lots of air and a need for large jets you would figure..

 

Here is a testrun with 120 mains...

 

 

You van hear it stumble in the high range rpms. Pulled the plugs and they were heavily soothed and near wet..

So resized the jets to 112..

And back..

 

So, I think the 117 is a bit big for a main on a stock VF500F engine..

 

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Ok, prepare yourselves for a wealth of knowledge.

TJH136V.jpgi6b92qd.jpg

WOT test #1 ^                                                                                                                  WOT test #2 ^

Yes, I can see they are both rich. Is this too much though? As far as I've been told a rich mixture is better for engine health. At what point does it become a problem? Neither of the plugs were wet with oil or anything.

 

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Here is my exhaust setup. 4-1 with no baffles

Now I'd like to explain the current state of affairs. I know about some exhaust and intake leaks. The carb boots are very stiff and cracked on one or two of them. It may please you to know that I ordered a new set of boots from my local dealer this morning. I will have them by Tuesday. I just hope they have survived 34 years sitting on a shelf. Next, the exhaust leaks. I can hear an obvious leak from one of the headers. I have tried to repair this leak, I went ahead and patched all the headers while I was at it. This was awhile ago. I notice a difference, but like I say I can still hear a leak. I used exhaust cement to seal the gap around the pipes. Ideally I should have done this while the engine was out of the bike. Removing the engine for the 3rd time is now on the to-do list. That is about everything that I know and have planned.

 

What exactly do the leaks do to the fuel mixture? Do my plugs look ok considering that there are leaks?

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10 hours ago, TheDutchy said:

We run the VF500F with open baffles and open airbox.. So lots of air and a need for large jets you would figure..

 

Here is a testrun with 120 mains...

 

 

 

 

 

 

I noticed when watching your video that my bike does not sound like it at all. Here is a clip I took today for comparison and diagnosis of my problems. Take note of my exhaust setup and the fact that you are listening to a VF500C Magna engine. I don't really notice any difference in power delivery compared to when I had the Interceptor engine in. Please tell me what you guys think given all this new information. I'd love to hear from someone who has had fuel pump issues

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My thoughts on plugs are 'a bit lean'? Maybe from intake rubbers.....
Second gap looks a bit big? Or is it just angle of the shot?
Weren't you also swapping out coil packs and leads? Maybe not a very strong spark.....look up a chart on reading spark plugs and symptoms from colour, deposits etc. Your CDI trigger box may be faulty(dry solder joints) so it works, but under load is breaking down.

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I don't think the plugs look lean but they don't look too rich either. I would quit second guessing this until you have the air leaks fixed. I also thought it sounded OK on the video so I am not sure you have too much to worry about. 

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On the vid... Do you really hit 5krpm ??  Take her up to 10K, that is the ballpark we take the engine..

 

Till 4K it is only the slow jet..(#38) To test the mains you have to take her up beyond that point..

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  • 3 weeks later...

I have a development to share. Just today I took the bike out for its last ride before I empited the coolant and oil. I noticed that my bike was running incredibly well in the cold weather. I let the engine get up to temp before I left the driveway, so its not the engine thats cold. Could the thicker cold air really make such a difference? What does this mean in terms of the fuel mixture? Yeah I know I still need to fix it before I ask this question seriously. Speaking of, I bought an electric heater so I can work on it in the shed this winter.

 

On 11/5/2017 at 1:23 PM, TheDutchy said:

On the vid... Do you really hit 5krpm ??  Take her up to 10K, that is the ballpark we take the engine..

 

Till 4K it is only the slow jet..(#38) To test the mains you have to take her up beyond that point..

 

I regret to say, but what you heard in the video is all its got. I have read up and again the vacuum leaks could cause an artificial redline of sorts. As far as I understand its because the engine cant get any more fuel or air to keep going. We are going to find out soon.

 

Pleeeeasse wish me luck with these next few weeks. I am having nightmares of cold bolts snapping in half

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Wishing you luck!

 

 

In colder air, molecules (including oxygen) move around/"shake" less, occupying less space. So per cubic unit flowing through your airbox there will be more (O2) molecules to feed the fire!

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Yesterday I completed the operation. I've got fresh carb boots and... umm this is going to sound funny. I got new exhaust gaskets too after learning the new engine didnt have any attached to it. I never took any out of the old engine, so I didnt know they were there. I didnt know they were there until one of them fell out and landed on the floor of my shed that is.

 

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Ta da! Some carb boots on the right. Before on left/after on right

I was able to do this in record time because I didnt remove the engine to get at the rear headers. With an arsenal of articulating and bendy socket extensions, I was able to remove them. 

 

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The winning combo was medium ratchet -> medium ratchet extension -> medium to small ratchet adapter -> small ratchet extension -> small articulated extension -> 10mm Spark plug socket. You can see my working space on the right.

 

The bike sounds amazing now. I think I can actually hear the cams on idle going "wop wop wop wop". It is too early for me to say whether I have gained any power or if its the placebo effect. Although the rpm problem still remains. It doesnt feel as boggy, but holy hell it doesnt sound healthy either. I will try to do another spark plug test soon once it is dry and warmish. May I ask, what speeds are you guys getting to with each gear? I'd like to know how this thing compares with whats going on.

 

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Yeah well, don't be too worried if you don't get 196km/h. Most of us don't see speeds like that unfortunately. A more realistic target would be 170-180km/h in top gear with standard wheels tyres and sprockets. 

 

And well done for getting those rear headers off. You aren't a gynocologist by any chance?

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I can decorate the hallway from the outside through the letterbox.... :-)

 

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nah...

I took the rear shock and the swimgarm out...

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1 hour ago, jeremyr62 said:

Yeah well, don't be too worried if you don't get 196km/h. Most of us don't see speeds like that unfortunately. A more realistic target would be 170-180km/h in top gear with standard wheels tyres and sprockets. 

 

 

Well then... before I patched the holes in my exhaust and intake I was topping out at around 110 before the gargle explody noises start. I have lower profile tires on which can account for a small decrease. I will try a top speed run once I am certain the new seals are settled in. Again the best way I can describe what my "redline" sounds like is rapid small backfires or gargling if that helps the diagnosis. Yesterday for the first time I accidentally fell from 2nd into neutral, but when I did the engine revved up to the stratosphere. Yeah I know its bad for that to happen, but my point is that the engine should definitely sound like that all the time when I am at redline.

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I've got some more info to share. I have been riding a bit and I've tested some higher speed riding. I'd say there is no difference in my top speed, but it does feel happier. I also tested bypassing my fuel relay, it made no difference. I tested the fuel pump output as well. The source I found says it should pump 700cc out of the lines with the petcock closed. I got way less than that, but 700cc seems excessive no? This is the forum I read

 

Also I was wondering if there is a way to change the ignition timing on this bike without doing every single valve over again? As per @Forbes ' suggestion

 

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If you are topping out at 110 km/h (units are mandatory in my world) then you have a very sick motorcycle and it really shouldn't be too hard to find the culprit. If on the other hand you mean 110 mph you have nothing to worry about. 700cc in how much time?

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IMAG9068.thumb.jpg.093bd1a3668f52843419126d97efdebe.jpg

 

My/the F2 left the factory w/o a fuelpump, but this is what the book says:

 

  • In principle, he pump relais will only work with the engine running. So we need to do the following
  • Make sure the petcock is in the ON or Reserve position
  • Remove left frame panel, start the engine
  • Clamp/close the thin vacuum tube (running from petcock) and remove from cylinder #1. now shut down the engine. By doing this sequence, the vacuummechanism remains active; fuel will keep flowing even with the engine not running
  • Pull the 3way plug from the fuel relais, jump the blue and black wires. Pull the hose that feeds the fuel and put that in a measuring jar
  • Switch on the ignition for 5 seconds, measure the cc's and multiply by 12; the pump should (indeed) deliver 700cc plus or minus 10%
  • If the pump is within spec, but it doesnot work properly under normal operationg conditions, check the fuel relais.
  • If the pump doesnot produces flow within spec, you need to replace the pump (after you inspected all the writing and hoses)

 

 

This what the book says, it doesnot describe how to check the contact points inside the fuel pump (I had to change those on my 4th Gen). donot know if the VF's pump can be opened and or serviced 

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On 11/25/2017 at 9:32 PM, jeremyr62 said:

And well done for getting those rear headers off. You aren't a gynocologist by any chance?

 

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Firstly, we are talking 110 km/h, but again I dont think there is any issue at all up until that rpm. 0-110 real quick, but not any faster

 

13 hours ago, Dutchy said:
  • Switch on the ignition for 5 seconds, measure the cc's and multiply by 12; the pump should (indeed) deliver 700cc plus or minus 10%

 

I did the test again with these instructions and I got a flow rate of about ~800ccs a minute. Does flow-rate relate in any way to the fuel pressure?

I asked about the ignition timing as well because something I've read about is the intake opening before the combustion is done. I did all of my valves to spec and maybe a little tighter than usual, but not my much. Given my previous experience of finding adjustment screws backed all the way out into my engine. Is there a way of adjusting the ignition on all cylinders at once? Also I was wondering if I could test a leaner fuel mixture by removing my air filter?

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