Royal Star Ronnie

Yamaha Royal Star 1998, black and chrome. 11,665 original miles on 6-10-2023, original owner. ME 880 Marathon tires with ~1,000 miles. Use non-ethanol recreational gas whenever possible. Garage kept with Yamaha cover daily. Heated storage in winter. Extra windshield. Extra seat (custom Corbin). Extra exhaust pipes (Jardine slash cut). Yamaha shop/service manual. Stebel horn (and original horn). Yamaha rear back rest. Yamaha saddlebags. Yamaha handlebar pouch. Yamaha winter storage stand. Yamaha lower wind defectors. Various Yamaha chrome pieces. Yamaha chrome rear fender storage rack. SAC luggage case. SAC duffle bag. Two Shoei XSP helmets with cases and extra face shields. Two sets of rain gear (used once). Two black leather riding jackets. Two pairs of black leather riding chaps. Wife no longer interested in riding for ice cream. Collectively, $5,000 (wife not included).

The Story: I have an original '98 Royal Star with only 11K original miles. And have just experienced loss of power and gas mileage after servicing carbs and an oil change. I tried to address most questions right out of the gate....so be patient with me. 1. Stored in air conditioned garage with Yamaha floor length cover. 2. Change oil (Rotella 15W-40), oil filter and gear lube yearly, and Sta-Bil for winter nap. 3. Dealer rejetted in 2002 with Dynojet 4148.001 and installed K&N filter at that time. 4. 2014 I cleaned carbs thoroughly: a. Replaced all 4 valve seats, 4 needle valves and 4 o-rings. b. Inspected and cleaned diaphrams, slides, jets and carb bodies. c. Set float heights at 8.5mm with 0.1mm tolerance (carbs up side down) required only slight adjustments. d. Per Dynojet: (No changes.) Fuel screws out 3.5 and circlip at middle (#3 position) on jet needle. 5. Synchronized #1-#4 carb vacuum while at 1050 rpm. a. Original exhaust. b. Premium gas. c. Starts instantly - no choke required at any time. 6. Idles smooth, but since carb clean: a. Bike has no guts from any speed. b. Top speed 73 mph (down from 105 mph). c. 20-25 mpg (down from 30 mpg). d. At approximately 2,800 rpm bike begins to pull much better in 1st-4th, but not in overdrive. e. No exhaust smoke. No fuel smell. No popping or backfires. 7. Checked all 4 spark plugs (DRP7EA-9) after ride and idle, and again after ride and throttle chop at 70 mph. All spark plugs are identical with: a. Totally white insulator (no deposits) along its full length. b. Light tan electrodes with ground electrode showing heat range coloration to 60% along its length toward shell rim. c. Inside of the shell (and its rim) is black but NOT sooty. d. All plugs show equal spark when grounded externally. 8. Fuel pump tested and working properly. I always shut off gas petcock when engine is off. 9. After removing gas tank and airbox, I reconnected the gas tank along side and started engine: a. Started and idled well. b. Attempted throttling caused engine bog and backfires at nearly all rpm's, which occurred with fuel pump feed and also with straight gravity feed from gas tank. (Apparently too lean without airbox restriction.) 10. See 4c. above. Pulled carbs (carefully leveled the quad) and checked float heights with external fuel level gauge and gravity fed gas source: (From center mark of diaphram cover to 25.4mm below - the Service Manual specification.) a. #1 - #4 are all exactly at the Manual specification. b. No apparent gas leaks anywhere, so I'm assuming the the valve jet(s) and valve seat(s) are sealing properly. 11. Oil level through site glass is 1/8" below upper mark when cold. a. No smell of gas from the oil fill opening. b. Could my crankcase oil volume be too high causing loss of power by increased friction? Review 6a-e and 11b above. Does this make sense...? Due to spark plug condition, bog and oil level, I'm thinking of: 1. Lowering each jet needle's circlip one notch to see if more fuel will improve performance and consequently mileage. 2. Adjusting the fuel mixture screws 4 turns out. 3. Draining engine oil to 1/8" above lower mark. Any comments, questions or wisecracks are appreciated. Otherwise, if I need to change internal carb components, then I might as well do it now since the carbs are off. Thanks to all.

My Corbin seat has a proprietary UPC sticker (with model number) attached to its underside. Contact Corbin with their build information and ask them specific questions. (800-538-7035)

Hucklecatt, your advice is logical, and after reviewing your links, I agree. My bike has always run well, except for this year's "popping" issue. I've reassembled the carbs with jet needle E-clips at #3. I'll remount the quad within a few weeks, but since local temps are ~40*F and rainy, I'll likely wait until spring to gas-up and sync. DynoJet indicates the pilot fuel screw has an unusually large impact on mileage with BDS28 carb, so after syncing, I plan to adjust the pilot fuel screws to the leanest position which allows smooth idle in hopes that my milelage will improve. Also, I wonder if Gunson's Colortune ($64) is worth it for optimizing the pilot fuel screw setting. Thanks again, and I'll repost with my final results.

Additional info: 1. Yes, main jet is #95 and pilot jet is #20. This is the first time carbs have been removed, so the inaccessible internals were original. 2. I have installed new float valves and needles, and needed to (slightly) level two of the floats to match the other two. 3. NOTE: I just found my original paperwork from the 2002 aftermarket muffler install and it shows a DynoJet kit #4148 was installed. The jet needles are DNO470 with instruction to set E-clip at #3. (The original jet needles were not given back to me.) 4. Jardine slash-cut mufflers, which are the same length as the original mufflers. 5. K&N air filter. Thanks for assistance.

Question #1: What is the default position (of the 6 available positions) for the circlip on the jet needle of a stock original BDS28 Mikuni from a '98 Royal Star? Bike: 1. Original owner of '98 Royal Star with 9,000 pampered miles. (Kept fully covered in an air conditioned garage. Oils and plugs changed yearly along with Sta-bil, etc.) 2. Ten years ago aftermarket mufflers were installed by a dealer and (as best I can recall) the dealer said he richen the carb to compensate for increased exhaust flow. He did not remove the carbs, therefore he must have richened by adjusting the pilot fuel screws and/or the circlips on the jet needles. (Hmmm, or maybe the jet needles were replaced.) Story: 1. Bike has seemed to run rich with 30 mpg, but has run well and started easily. 2. Rebuilding all four carbs due to afterfire from right rear cylinder believed to be carburetor related. Right rear carb was indeed dirty(er) within float bowl, and had a slightly sticky jet needle slide as well. 3. All four carbs are fully cleaned and ready to reassemble with new o-rings and new float valves and needles. 4. Spark plugs are all equally colored with clean white insulator, sooty plaque on threads, and light brown electrodes. (Thoughts?) Naturally, I will resync carbs as well as adjust the pilot fuel screws, but I'm wondering if I should alter the circlips position on the jet needles. Current circlip positions are #3 (down from the top clip end). Question #2: What are your thoughts about leaning it out a bit by installing the circlips at position #2? Thanks.

The good ol' days! And it all happened everyday; rain, snow or shine!

Any installation pics? Also, which model Biker's Choice tach did you purchase, BC-49-0293? Thank you.

+2 !

It's an Obamanation. I'm a struggling self-employeed small business owner with three kids in college. Over the last 11 years I've gone from 3.5 employees to 1.5 employees, and written off more than $1,200,000 in uncollectible charges. WTF! Nobody is lining-up to bailout my arse. No pension for me. Yep. Let's keep bailing out the big-boys, and ignoring the illegals; that's the answer. We all have to take our lumps and keep moving along.

Would you please post a pic of this brake reservoir tach? My 1998 standard Royal Star has no tach, and I want one. Is this tachometer "plug-n-play"? If so, exactly where does it plug in? Thx.

Original owner of '98 standard Royal Star with 9,100 miles. Lol; it stands pristine and covered in a heated garage. BTW looking for 'plug n play' tachometer. Please post or PM links. Thx

:15_8_211[1]:Rode Royal Star 52 miles to purchase Pressure Plate for YZ250F clutch rebuild. Then rode 54 miles of MI tight whooped-out single track trail http://ktmtalk.com/html/emoticons/whoop.gif . Need Aleve badly. 52 yo knees can't take that chit .

Here is my c.a. (cheap arse) version. Works great, but takes longer since you have to move it around for each paired sync. 30' of tubing, 50ml gear oil and an old board.