Finally Shimmed Needles...What a difference!
 

I bought my bike new in August of 2005, and it's got 29,000 miles on it. I've been putting up with the Carb Farts during warm-up, occasional stalling, and surging & farting at low speed below 3500 rpm, but I finally decided to take the advice of multiple other threads and shim the needles. My bike has stock cans and air filter.

It'll get a test ride tomorrow, but I started it tonight after putting it back together and WOW, what a difference.:D It has RARELY started cold and ran for 10 minutes without popping or stalling.

I have 2 reasons for waiting so long to do this...1. I'm a procrastinator 2. I'd rather ride (or surf) than work on my bike. The dealer wanted 4 hours @ $85 per to r&r the carbs, so that motivated me to do it myself. Plus I think I pay more attention to detail than many techs.

I bought #4 brass washers at the hardware store for 11 cents each. I don't have a mic at home, but comparing them to a feeler gauge they appear to be about .020" to .022". The only problem I had with the carbs was getting the diaphragm lip to stay seated in the groove while installing the cover and spring. I solved this by using the handle of a Craftsman # 1 Phillips screwdriver to prop the slide open. It's just the right size that it doesn't put any pressure on the needle.

So I'd like to thank all who have advised others in the past to shim the needles.:thumbsup:

That's easier that it sounds, if someone can remember how he removed the hardware and put it back as it was.
For the diaphragm, the slide halfway open usually make it easier.

Glad you sorted this, happy riding.

Glad to hear that you are happy with the results!

I have a post in the KB somewhere that describes the easiest way to get the diaphragms to easily set in the recess...KB#6

Yeah, the screwdriver trick made the second diaphragm a 1 minute job. It did hold it 1/2 open.

I was especially careful with the plastic nut on the "choke" cable, very fine threads that can strip easily. Patience is the key. When cars had carbs my students would commonly strip the fine threads on the fuel filter housing on Rochester Quadrajets, the most common carb of all time I believe. (I could just about tear down and reassemble a Q-jet blindfolded) I had a rule for my students=start all threads by hand for at least 3 full turns. Not everybody listened.

This was the 2nd time I had the air box off, and both times I had to go back and redo something to get the sequence right...Damn front PCV tube. The 1st time I aborted on the needle shim when I discovered the carbs had to be removed to get the front diaphragm cover off. I removed the EVAP valve and canister that time.

Thanks again for all the advice on other threads. It's misting outside today and I'm due for a new rear tire, so my test ride will have to wait.:(

I just tore apart the carbs AGAIN! (about the 5th time this season) and I think I finally got it all good. If you remember the first time I had a gas puddle under the bike, water in the fuel, and fuel in the airbox, cylinders, and oil. The second time I petrolocked the rear cylinder again. Still some water. Also found clogged idle jet. Third time clogged idle jet. More water. This last time same shit, but less water. I blew out every port on the damned things and it finally idles decent again. I betcha it's the cheap assed gasahol we have up here in the northeast. Maybe when I winterize this fall I'll drain the tank and throw some dessicant packets in the tank!

Oh, and you're not alone. I missed the front breather a couple times myself. It's impossible to put on without taking everything back off again.

Dude, you got screwed on the price. I'd take those back and shop around a little more.

Well I finally got my bike out for a 1/2 hour test ride this morning, and I can't believe the difference from a .020" needle shim.:D Not one carb backfire or stall the entire ride, that has NEVER happened. I should have done this 3 1/2 years ago.

Off idle throttle response may be better as well, but it's hard to tell since I didn't notice a problem there before.

I highly recommend this fix to any forum members who are experiencing these symptoms. The needle shim is relatively easy once you get to the carbs.

Greg,
Ethanol is so much BS. Manufacturing of ethanol cancels out any gains in carbon emissions. Corn is for eating. Sorry to hear of your unwanted need to become a VTR carb expert.

Well, I've BEEN an expert! I just regained my proficiency. :mrgreen::mrgreen::mrgreen:

I understand. I found it much easier to start a job when I was wrenching for a living or teaching. The main proficiency I lack is motivation to get started when its my own vehicle.

I seem to have motivation to start, but I run out before things are finished. Especially true when things get complicated. For example, I've got three bikes torn apart in my garage at the moment, only one is mine. Dad's KLR250 is kicking my arse with a nasty flat spot between 2 & 3k, I need to re-clean the carbs on his XS400 because now the other one must have worked gunk lose, and the VTR is coming back apart to clean brakes, reseal forks, and grind steering stops.

I never wanted to work on the VTR much before as it was my only bike, so I went and bought another one to ride while I work on the VTR. I haven't been able to park my truck in the garage all spring, and I doubt I'll be able to for a few more weeks.

Surfer;

Congrats on the success of your mod. After pulling and jetting my carbs about a half dozen times, I ended up with DJ 175f/180r and needle on the fifth slot. That, I believe is about the same as your needle shim. Together with adjusting the TPS down from 850+ to 500 has given me a perfectly running/perfect throttle response VTR.

Thanks, with stock cans and filter I didn't think I'd have to rejet, but I am amazed at the difference a .020" needle shim makes. I thought I'd still have to mess with the pilot screws, but evidently not.

My wife and I are talking about doing the Crest next week, starting from the Wrightwood end.

Surfer;

Angeles Crest is a great ride, but being one of the world's most noted bike paths, it's a better ride at dawn on Monday than it is on the weekend.

A great option, one of the unsung great rides, is to take Big Pines Highway south out of Wrightwood. It's my favorite local road. You can run down to Little Rock or Pearblossom for gas and food. Take Angeles Forest Highway (Ca. route 2) over to La Canada/Flintridge and then go east on the 210 to the 15 or west to the 405/5 to get home.

Big Pines highway kicks ass. I've ripped it for 10 or 15 minutes at a time on a weekday morning without seeing a car going either direction. Just my opinion.

In the early to mid '80s my buddies and I did the Crest once, west to east, on a Sunday. No traffic east of Newcomb's Ranch. We also rode Angeles Forest several times, and NOBODY was on that road back then. Also Little and Big Tajunga, Bouquet Canyon, and many others.

Since we're both retired we're going to do it mid week, riding east to west (gas up in La Canada/Flintridge), then back to Wrightwood to spend the night. We might try that road out of Big Pines before heading home the next day.

Angeles Crest on a weekday is fine.

And a correction; Big Pines Highway is down hill but NORTH out of Wrightwood.