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airdog84

New Member 98 VFR - Starting Cold is not great

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Hey Guys, 

 

New VFR owner from MN here. Bike has 17k and is in great shape. Biggest thing right now is that when it starts it requires the coke to be pulled fully then it starts and revs really, really slow. 

Once the bike is started it runs a bit stronger.. I need some help with this and will try to upload a video later today. Another thing is that when I blip the throttle after the start it kind of "flubs" almost like it's going to die... after it's hot there is no issue. --- Thoughts??

 

Here is what I know from the previous owner

-Guy owned it 19 years and barely did maintenance himself

-The Fuel pump and brakes were all replaced/bleed last year - Rear brake pedal feels like a block of wood.. It brakes alright but man you have to push it down hard.

-Air filter and oil changed last year

-Coolant was flushed a long time ago (maybe like 10 years)

 

Other than that it's fully stock bike.  I would love any tips, Must do maintenance, free mods that help etc. My goal is to keep it stock, just want it to run and start correctly.

Thanks

 

IMG_5122.HEICIMG_5118.HEIC

-Airdog

 

 

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17k miles in a little over 20 years means the bike spent a lot of time sitting and when it did run the trips were probably short. 

 

1. So the spark plugs might not be in great condition, you could replace them (fouled spark plugs contribute to hard starting). 

 

2. If the prior owner was not a confident wrench-turning type of guy the valves probably have never been inspected for proper clearance and adjusted if necessary (tight valves contribute to hard starting).  Another reason that the valves don't get looked at is the procedure cost a good bit to have it done at the dealership if the owner can't do the job himself. 

 

3. There's also a pretty good chance that the Starter Valves haven't been adjusted (synchronized) in a very long time, maybe they've never been adjusted (poorly synchronized Starter Valves contribute to hard starting).

 

Taking car of those three items should bring the engine up to a pretty good standard.  If this doesn't completely solve your issues, it'll be a very good start toward it.

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Good advice from Greg.

 

 

VFR fault find.png

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Welcome to the asylum airdog84 from a fellow Minnesotan. That is one fine looking fifth gen. You obviously have great taste in mc's. Good luck with your resurrection. 

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Thank you for all the helpful tips.

 

im not a very technical guy, oil changes and spark plugs no problem but many of these other things will require a professional. 

 

Hey Max swell, do you have any MN mechanic recommendations??

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Well took the bike down to Red Wing for a ride yesterday and the rear brake caliper locked up.. froze the caliper to the rotor and I couldn’t push the VFR. 

 

I waited on the side of the road after calling my insurance then my buddy said let’s try and roll it again. We rolled backwards and the caliper has released over the time we waited. Drove 90 miles home with no rear brake applied... 🥺😐.

 

one more thing to add to the list.. bummer as in MN our season will be done soon.

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If you haven't already put fresh gas in the tank. Will help starting for sure.

 

Try A good quality injector cleaner in a few tanks of gas. It might clean things a bit and help with the starting.

 

The rear brake pistons might be stuck on their seals, making the pedal feel wooden. Might be worth cleaning the caliper around the pistons with brake cleaner and squeezing each piston in a little manually and out a little with the pedal to free things up. Be careful not to pop the pistons out.

 

A flush of the fluids, oil and coolant should be on your to do list (the brakes and clutch can be a little tricky to blead). And check the age of the tyres.

 

Enjoy the bike.

 

BTW, I've got a Y2K model with 50000km on it in blue.

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I got your Personal Message and have replied. I'd love to meet you to talk shop, tell lies and generally bs about these fabulous machines.

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A locking rear brake is a sign that all is not well in the secondary master cylinder which resides on the left fork leg. Could be either the pushrod is seized or the compensation ports are clogged. You should plan on pulling this off and giving it a careful clean and possibly a rebuild kit, cleaning out the master cylinder reservoirs carefully and then giving the brakes a very good flush. 

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For the Fi system to work as designed on start up the butterflies must be 100%
closed... this is because close butterflies equals sufficient vacuum... without
sufficient vacuum the fuel cannot be drawn into the combustion chamber to
support start up... the result is hard starting... the drill for cold or hot start is

    1 100% close throttle for sufficient vacuum
    2 Full choke when cold no choke when hot
    3 Hit start

Eliminate the possibility that the throttle body butterflies are not
closing 100%... if any any air is bleeding pass the butterflies then
the metered flow of the idle air can not draw sufficient fuel to support combustion...

 


The dead give away of an air leak on a Fi engine is high uncontrolled
idle... on a fuel injection system *any* air that gets past the
throttle bodies the map just adds the corresponding fuel... the result
is high uncontrollable idle... make sure all the rubber hoses are
connected and in good shape... make sure all the intake boots are
tight and in good flexible shape... if the rubbers are hard and
cracked its time for replacement...

 

Allow me to illustrate what is happening when you pull the chock lever
on Honda's fuel injection system... note all you are controlling with
the knob marked "choke" is the amount of air through the starter valve
circuit... the more air the senors see down wind of the injectors more
the map automatically increase the fuel... the result is control
idle...

gallery_3131_51_651212.jpg

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On 9/5/2019 at 2:52 PM, Terry said:

Good advice from Greg.

 

 

VFR fault find.png

Its possible this troubleshooting guide is for carbs not for Fi equipped VFR... below is from the offical Honda VFR800 manual...

 

VRF800HardStart1.JPG

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My cut and paste was direct from the 5G manual in the fuel section (chapter 5).  

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Hey Guys, 

 

Thanks for all the helpful tips. I feel like I'm drinking from a firehose.. 🙂

Video here at Youtube of me starting the bike cold.

 

 

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With full choke no throttle the cold start sounds normal...

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3 hours ago, airdog84 said:

Hey Guys, 

 

Thanks for all the helpful tips. I feel like I'm drinking from a firehose.. 🙂

Video here at Youtube of me starting the bike cold.

 

 

My '99 has started like that since new.  It needs about 1/2 the lever's travel or a touch more to start well, that's about all I ever use.  After about 30 seconds it idles fine without, which is when I cycle the lever back until the next cold start.  Ride it and don't worry about it. 

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Well that’s good, I’m still going to check all the great tips you all gave me when I tear into the bike. Should only get better

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O the right side of the bike, on the exposed aluminum spar there is a small rubber cap that can be removed to expose an opening; insert a phillips head screwdriver until you feel it mesh with a screw about an inch into the hole.

You could raise your idle to  1,300 + or  - 100. Turn to change the idle. Turn clock-wise to raise the idle. Engine should be warm.

The Owners Manual says: if it is a cold start warm it up with a 10 minute stop-and-go ride. Mc should be on center stand on a firm and lever service. Shift into neutral and adjust.

 

BTW: Phillips head screws were developed by the auto industry to be self-torqueing - the screwdriver will spin off the screw at a predetermined torque.

Japanese mc manufactures use a JIS screw and screw driver that will not spin off. I bought a three-piece set as recommended by Consumer Motorcycle News  https://www.mcnews.com/ (This is the best of the mc news rags).

Check out:  https://www.vesseltools.com/handtools/screwdrivers

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1 hour ago, MaxSwell said:

O the right side of the bike, on the exposed aluminum spar there is a small rubber cap that can be removed to expose an opening; insert a phillips head screwdriver until you feel it mesh with a screw about an inch into the hole.

You could raise your idle to  1,300 + or  - 100. Turn to change the idle. Turn clock-wise to raise the idle. Engine should be warm.

The Owners Manual says: if it is a cold start warm it up with a 10 minute stop-and-go ride. Mc should be on center stand on a firm and lever service. Shift into neutral and adjust.

 

 

I don't know if you're doing it on purpose, but you're quoting the California-only VFR800 idle speed setting.

 

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that startup sounds fine. full "choke" on start till the engine hits 3k rpm then drop it. completely normal.

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Torn into things tonight. Tank needs drying out to clean out the light rust. 

 

Cleaned out our the air box.

 

i watched a youtube video of a guy who had a black VFR that he bought to bring back to life. When he twisted the throttle fast the motor would die due to no air movement. He showed the two holes below and when he put his fingers on them it would die immediately. Guy stated in the video that the master air line was dirty. 

 

After the guy cleaned it (not sure how he did that??) his throttle response came back. 

 

I checked the hoses that were connected to those two holes and mine where clear? Am I missing something.. because my bike would putter when I would twist the throttle fast too. Just want to make I do what is needed with it open before I put the air box back together.

 

Lastly, anything else I should check, remove or replace before I put the air box back together? Hoses look old but no cracking

 

thanks

8326D2FE-D8DB-498B-B506-CD8EE5C8E290.jpeg

BF5F66B5-736E-4C7B-9B96-922DF47BCC31.jpeg

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Those two holes admit air into the Starter Valve system.  Nothing cosmic going on there, just make sure you get them reattached as you're putting the airbox back on.

 

After you get things reassembled you're gonna need to do a Starter Valve Synchronisation, see the Service Manual on page 5-67.  That will help to sort out the stumble in your off-idle acceleration.

 

When you're putting the airbox back onto the throttle body you want to be very careful to make sure the MAP sensor is connected properly.

 

 

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3 minutes ago, GreginDenver said:

Those two holes admit air into the Starter Valve system.  Nothing cosmic going on there, just make sure you get them reattached as you're putting the airbox back on.

 

After you get things reassembled you're gonna need to do a Starter Valve Synchronisation, see the Service Manual on page 5-67.  That will help to sort out the stumble in your off-idle acceleration.

 

When you're putting the airbox back onto the throttle body you want to be very careful to make sure the MAP sensor is connected properly.

 

 

Got it, my Service Manual won’t be here for a week. Also, Is the MAP sensor the grey plug in or the whit one on the bottom of the air box. Thank you!! 😄

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I didn't know you were without a Service Manual.  There's an electronic copy of the Service Manual available here on the forum.

 

The MAP sensor is attached to the bottom right-hand side of the airbox.

 

The white sensor on the bottom of the airbox is the IAT (intake air temperature sensor).

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13 hours ago, GreginDenver said:

I didn't know you were without a Service Manual.  There's an electronic copy of the Service Manual available here on the forum.

 

The MAP sensor is attached to the bottom right-hand side of the airbox.

 

The white sensor on the bottom of the airbox is the IAT (intake air temperature sensor).

 

Here's the link to the service manual, fyi. Also - the hoses you have blue taped in the earlier photo are the hoses you use for the starter valve sync and, if you look closely, they are numbered for each cylinder from the factory. 

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