After a failed attempt at rejeting, my 2000 1100 Classic has never been right. I had the carbs rebuilt again, by a professional at a well respected Yamaha shop in Watkins Glenn, N.Y.

I put the carbs on, and flushed the crank case/changed oil and filter hoping to fire the bike, make a couple minor sync and idle adjustments and be on my way...........NOPE.

The bike started right up, which was a pleasant surprise after sitting for a couple of years with only a few start and warmups. Sounded fine, but when I took it off choke, it idled down and died. I started her again, and discovered that the rear cylinder is not running.

I changed the plugs after accurate gapping and got the same result......even though the rear plug IS firing.

Upon performing a compression check (3 times/same results) I am seeing 130 psi on front cylinder, and 180 on the rear! This is odd, and very high on the rear cylinder, whereas the front is 1 psi below the "rebuild" recommendation. 

If anyone can please offer some advice, I will be forever grateful. Losing my vision to glaucoma, this will be my final season of riding after 53 years, and I would like to be able to cross it off my "bucket list" before the darkness consumes me.

She's been a good girl, and taken me 164,000 miles asking for nothing but gas, oil and tires, but I am in no position to have her rebuilt, if that's what's necessary.....won't she make a pretty little lawn ornament?

Thanks, as always for your time and advice!

First question is always.....did you have the throttle fully open when you checked the compression? If so....you may have picked up a piece of crud in the pilot jet on the rear carb.....the side holes are usually the culprit.

Hi Mick! And THANKS for getting back to me. Actually, I did NOT have the throttle open when I did the first compression check. After learning the proper way to do it, the pressures were even at a solid and stable 160psi.

After finding this, I took the carb off the cylinder that was not firing, and cleaned all the jets. I did find some blockage.

Fast forward to post-instal: The bike now starts right up and both cylinders are firing, but pop pop pops, and when I take the choke all the way off, she idles down and stalls, unless I keep blipping the throttle.  

Point of interest: Now that the rear cyl. is firing, the front cyl. that was OK from the start, is popping along with the rear.

I am at a loss, and frustration is getting the better of me. Any advice will be gratefully received! THANKS!!

Make sure your idle is set a 900 RPM. If it is, what is the PMS set at? If the idle is correct, the popping is usually a lean condition at idle. Try them at 2.5 to 3 turns and check it out.

Hi Mick!

Sorry to be such a pain in the @ss, but mine's been kicked for months now, and I'm almost there, but the seasons getting shorter and I haven't ridden further than around the block yet!

The carb situation has me baffled, but I think I'm creating more problems than I'm clearing up.

The bike RUNS now, and quite smoothly when underway. The problem is, at idle she pops from the front cylinder, idels down after a couple of minutes then eventually stalls out unless I have just a touch of choke going on.

I can't sync the carbs, because they are miles apart and crazy jumpy. Also, I am unsure (but guessing) that the PMS screws MUST be turned out the same # of turns? If I do that, the front cylinder stops firing. The rear carb is 2.5 turns out and with the front 3.25 out is when the bike runs the best. pretty smooth with minimal popping. Under throttle she's fine, but when I back off, she pops and gives me the feeling she wants to drop dead and toss me over the bars.

The carbs have been cleaned "4" times (2 by me, 1 by (pros?) and again by me, the tank was flushed and the fuel pump and filter are new.

I realize this is an old ache, but I sure appreciate your help!!

The carbs MUST be synched. That's probably 90% of your problem. You can't set the PMS until they are synched. It's a very simple process. Do a bench synch to get them close....then a vacuum synch once the carbs are back on the bike. All the info you need to do it is in the KB.

SwaMan (swa3) said:

I can't sync the carbs, because they are miles apart and crazy jumpy.

Make sure you put pilot jets in the sync hoses, this dampens the "jumping" by limiting how fast

air can pass through the hoses.

I'll make your carbs right, if you are still having problems. Just mailed a pair back to NC, he had the same problems, he took it to a professional mechanic. LOL

HYA MICK!

GOOD NEWS!......I finally resolved the "failure to launch" issue with the old V Star! After screwing with the carbs for months and months, I finally found that the "pro" that had them last, did nothing for me. I started from square 1, and was able to find a very serious vacuum leak  due to the 22 year old carb boots being cracked like the bottom of a dry lake!

I replaced them, and was able to fine tune my bench sink to the point of having a great running bike again!

I still have some popping on decel, but having a little fluid from my homemade manometer sucked into the engine revealed that the front exhaust header gasket was shot.  Have them on order, and looking forward to getting a couple of good rides in before the snow flies here in NY.

Quick question though: there was N-O gasket of any form on the front exhaust/header pipe union. And I mean NONE. The connection is even different, as in the rear connection has a collar for the gasket to hug, while the front has a flat surface on both the pipe and the cylinder head. The gaskets come in identical pairs, but I'm confused as to whether I should put one in the front, or is some sort of sealant used? I'm quite certain that I should have found SOMETHING there upon disassembly. Almost to the point of being able to leave you alone, and forever grateful for all the help you have provided throughout this long and painful summer! You are a patient man, my friend.

There should be a gasket on the front as well as the rear.