Which pilot (slow) jets for a '96?

My '96 VFR750 has been getting progressively harder to start during the last few months, and when handed over to my mechanic (his last name should be Honda - he has every motorcycle-type certificate issued by Honda,) he suggested we go up one step on the pilot jets. This seems logical to me, as the new Remus can I installed earlier this year should cause it to lean out a bit.

The trouble comes when trying to find the right jets. The Honda dealer I work at (I just do new set-ups) recently lost about 35 years' experience in the parts department, and the new parts guys have more trouble finding parts than I do.

Does anyone know the Honda part number for a size 42 jet for my bike? Or the Tucker/Rocky number? My service manual simply gives the carb type (34mm CV) and id number (VP34A). The DG Keihin pilot jets listed in T/R have: Series 21 (PJ, PWK & smaller PE carbs), and Series 22 (PE carbs from 34-38). Which, if any, are mine?

Maybe I shouldn't even worry about it, as I plan in the near future to convert it to fuel injection. Anyone done this, by the way?

 

Perish the thought it would be very difficult!!!!


Here are links for jets: http://www.sudco.com/keihin_pj.html#22
http://www.sudco.com/keihinjets.html


I do not agree with your mechanic, the slow set should not need to be changed. Did the starting problem occur when you installed the exhaust canister? Have you had the carbs off the bike and examined the slow jet for dirt / blockage of the side orifices? I would examine the cards closely (I use several magnifying lenses), clean then, check the float heights, ensure the choke is operating properly, synchronize them. And this would be after I checked valve clearance, compression and gave the ignition a once over. I realize the average guy is not necessarily going to pay for all this work but this is what I would do if my engine was difficult to start.

 

I talked to my dad who works for Honda. He gave me some #'s

-The stock pilot jets are 40's

Slow jet #40
Honda # 99103-MT-0400

-42's would be

Slow jet #42
Honda # 99103-MT-0420

 

HEY,

why not try opening up the mixture screws another 1/2 turn??

(But, damn it's a BITCH getting the screws turned on this bike !!)

You can easily buy an injected VFR cheaper than converting yours ; old-fashoned, i much prefer carbs to FI !

 

Perhaps a thorough cleaning is all that is needed. However, I got the bike last fall after sitting for... no one really knows how long. At that time, my mechanic totally rebuilt the carbs, found a mis-adjusted throttle linkage, adjusted it correctly, & then sync'ed them.

She ran absolutely flawlessly until about mid/late-February. Due to the weather, she ended up sitting (in the garage) for about two weeks, then would not start. I installed fresh plugs and she fired immediately. For the life of me, though, I cannot remember if the Remus can and high-mount pipe were installed before or after.

In any event, the bike ran like a champion again, up to and including a 1000+ mile trip over the 4th of July (should I mention I got her with just under 6000 miles and now have just under 14?) A week later, the extreme backfiring on deceleration and the feeling of only running on two or three cylinders during warm-up or until vigorously throttled led me to think a plug or two had fouled. While installing new plugs, I discovered an absolutely filthy air filter. I ordered and replaced the air filter and sub-filter, and even back-ordered a BMC filter for the next time. Removed the new plugs before attempting to start, reinstalled the old plugs, but she wouldn't start. Put the new plugs back in and she started right up, backfire was now gone.

Regulator/Rectifier fried itself in August and was replaced with the upgraded Honda unit.

She ran great until the end of October when the hard starting began. During a snowstorm, I fired her up in the garage and ran her (with the garage door open, of course) for a good 30 minutes. Was hard to start, but ran fine once started. Two days later, nothing.

Checked spark on all four cylinders - was there, but weak. Checked fuel delivery and found a small leak at the pump, so I ordered both new hoses. Replaced the plugs one more time, and she fired right up. It was at that point I decided to take her to my mechanic.

As I'm sure everyone both here and over at VFRD would agree, when the VFR is running right, they're dream bikes. Unfortunately, I simply do not have the experience or tools to work on multiple carb'ed engines, whereas I feel at home with fuel injection. Difficult, yes. Impossible, no. I love my 4th gen. but I'd also like to be able to take care of her by myself, if that makes any sense.

 

No takers on troubleshooting this? I do want to add that when the bike began starting hard (end of October,) I noticed that my mileage plummeted to about 25 mpg. Also, the fuel filter was replaced when the hoses were.

So, she's not running at 100%, and she's using almost as much fuel as my truck, but the sound coming from that Remus can is awesome! More like the cackle of a small-block hot rod with cherry bombs.

Any and all help is greatly appreciated, as I'd like to have her running right before I begin some winter mods that should be quite interesting when done.

 

crappy running and low fuel mileage suggest choke cable maybe not returning fully to off position.

check your sparkplug colors and replace if fouled