garyS-NJ

quite coincidentally, I was rebuilding the starter for my yam xj550 yesterday and it has 4 brushes and a permanent magnet for the stator field. I haven't opened any two brush starters and didn't think about how they generate their static field. Not to spend too much time on this and I would figure that plenty of guys have looked into it anyway but I didn't want to buy a used 4 brush starter that was a slip fit and installing a new brush set to freshen it up THEN find it was same parts as my old one... I looked on ebay and found one 2nd gen starter (I think) and it had Mitsuba P/N SM-229. but I thought that was a 1st gen starter? Way to confuse a thread garyS(started as popping out carbs and steve below is talking about valves which I suspected/dreaded). Anyway, I looked up starters and foundI think 1st gen is 26H-81800-10-00 and the 1996 and up second gen is 4NK-81800-00-00... but they both look like two brush starters (although early has replacement brushes and later has a brush set ). just because we're on starters now, can anyone clarify?

Good point on the stp. Will see how it grabs. Was runnjng a lot better today. After she's road worthy I'll do the starter. Might only mean a bottom hose. Does a 4 brush plate fit in the old starter?

Yea I just bought $5.00/ oring from stealer for my xj550 carbs.. after the same looking sae buna orings leaked. proprietary. Smh.

Yes, definitely I'm about saving $40 if I can make it happen easy enough.. and I thought the Viton tips went in metal seats (which may well be installed in the body with O-rings) and the metal tip needles go against tiny rubber O-rings pushed into the seats. Small engines mostly had metal pins and O-rings and we had a special tool to remove them (air compressor) and special tool for installing them (4mm allen key with spit or oil if you're feeling sexy). I'm going to soak/spray/squirt my carbs to clear them if the old girl doesn't clear up udling on the seafoam (it won't) and I understand I can split the rack in two without needing to resync. will see if I can dunk those pairs in the gallon of chemdip but I'm sure to need the rubber parts. does anyone have a carb kit or list of the rubber parts for my '84 XVZ1200?? (not to hhi-jack and I'll post a new thread but figured this one might get traffic too (and I'll probably be changing something rubber in the needle/seat too!).

I thought the chem-dip would swell/kill rubber orings.

does anyone know of a kit to rebuild an '84 XVZ12? ebay has older VMAX and XVZ13 carb kits (link shown above) and so I asked the seller if they would fit... also/otherwiser, is there a tech note somewhere that tells all the rubber rings/gaskets by P/N that should be replaced to soak/spray/blow the carbs clean??? I'd rather get the parts before I disassemble and also like to avoid looking at the exploded view and writing all the P/N's.... yes, I'm lazy. lastly, looks like my XVZ12 needle seat threads in and the needle is metal so I imagine I definitely need that little o-ring (and the seat will be fine with some polishing,,,.).

at $17 each for the stock parts (needle and seat) wouldn't it make sense to do that instead of modifying parts to correct fuel level? and looks like that seat must have an o-ring as the needle is metal. is the O-ring included? not shown with stock needle & seat assy P/N.

Holy **** my little '83 xj550 has 4 brush starter. The starter has to cool? So when the motor is hot it makes the starter hot and it don't crank? How the hell did that design pass?

well today could have went better. I did the shotgun and even shot some chemtool through. I did the squirt/blow three times and also polished one slider that was a little slower than the others to snap back. It ran better with the airbox and filter on but was slow to warm and didn't want to come off choke or rev. It popped a little less and reved better but not good enough. I'm also seeing that after it warms, it cranks slow really loading down my spare battery (with a charger and 50amp start boost). I'm going to run it a few times with seafoam in the gas hoping that clears things up some. and I just read about another tune up in a bottle called Liquid Performance fuel system cleaner. I know this stuff rarely works and may well eat the rubber parts but I'll be replacing the rubber parts anyway in the rebuild if I have to tear them down. And I'm hoping the slow cranking when hot is due to "sticky" rings from the seized engine and this will loosen up as I run the engine. I used diesel oil (because it has zinc) and added some STP (with zinc) and a bottle of ZZDP Max (zinc!!!) hoping this lubes up everything. maybe I need some marvel mystery oil or seafoam in the oil (that's OK as I bought more oil to purge the crank case again...... Could my starter brushes be tired?? I read somewhere that the first gen starters are lame and should be replaced with second gen starters (or brush sets?) but that starter under the from exhaust pipes will suck! (I sprayed the studs figuring I'll have to do that sucky job..).

reaching into the throats, one slide was seized and the rest reacted different when I pushed them in and let them spring back out. so I used a plastic abrasive pad to scour the slides and the slide tubes using PB blaster as a lube/cleaner - careful to keep the throat pluged with paper towels. this smoothed out the sliders and then running I could see them all pulsing the same with vacuum except for number 3. I just took that slider out again but it was moving freely so I'm guessing the vacume to the diaphragm isn't working properly. can't see/understand that vacuum path from the carb cross section in the manual. Oh and the mixture screws were unplugged already. gonna count the turns in on them and then remove them and spray them out and then set them an extra two turns out to try the "peashooter cleaning method" (see below) and try with assembled airbox before yanking the carbs for a real cleaning.. you know they always say don't fix what aint broke so I don't want to pull these carbs and taka a chance screwing them up if I'll be able to ride it (as least for a week or so to check it out and while my other bike is down waiting for parts...)

big thanks Prairiehammer!!

now that I think of it, I saw a youtube video of a guy shooting a carb cleaner into the throat jets with the idle mixture screw turned two turns out (pea shooter carb clean), but this video shows a guy running his venture with the airbox off and he's not having any issue with popping or bogging. I'll try it with the box on today but looks like dems carbs need to be pulled off and gone through.. would a compression gauge while cranking the engine check the valve seating well enough? (hate to do the carbs and find it was intake valves not closing well). runs without airbox:

The pistons/rings were sized to cylinders. I broke them free with penetrating oil and Evaporust. Rocking the bike in gear and finally rocking while tapping on the pistons with a rod thru the rear spark plug holes.. I'd think the TV I would either work or not work. Yours was half dead. I have spark on all for cylinders. What about the diaphrams on top??

OK, everyone is saying try it with the airbox back on... but to be clear, when I rev the throttle (even bringing it up slowly), it starts to backfire and pop (flames) out the carb throats. it also self limits and refuses to rev as it starts to bog and pop. I used to work in a small engine shop and whenever a motor acted like this we would fix it by cleaning and rebuilding the carb (they were a lot simplier but I guess the same!). as for the Pilot screws Von Wolf, do mean the capped (but adjustable) pilot screw (idle mixture I think) or the Pilot Air Jet 2 under the diaphragm (I squirted carb cleaner throught here and it came out top the carbs), or one of the purge jets 1&2 beneath the diaphragm at the bottom near the mixture jet?? or are you talking the Pilot Air Jet 1 or the Main Air Jet near the throat. What about the diaphragm on top of the carbs?? popping out carbs usually means way lean so maybe I just have to slick up the one sticky slider (yes, one looked sticky after all four were done) and try it with the airbox on to restrict the air in. I kinda remember I was working on a newer inline 4 sportbike thaty wouldn't rev without the airbox... (gone are the days of wide open anything).

test to reply

wow, I typed the title carbs popping and I see there's similar threads. I'll look at them but in the meantime, let me post here hoping I have some guidance to mount another attack in the morning.. long story short - I recently bought an '84 venture royale complete with bags and plastic.. it looks stock. electrics work but it was seized. I got the pistons moving and it ran just adding gas. but it was spitting fuel out the top of one carb and wouldn't rev without spitting popping and bogging. and the carb drains were clogged. I flushed the tank and installed a new fuel filter and blew out the bowl drains (crap, I blew one hose off the front right carb and can't get that sucker back on..). one slider was completely stuck and a few of the sliders seemed real sticky.. so I cleaned up the sliders and sprayed carb cleaner and air through the ports under the diaphragms.. then I sent a mixture of gas, carb cleaner (B-12 chemtool) and seafoam through the carbs (I let it sit for a bit) and then flushed with fresh gas. she fired again but took a while to warm up and get off choke. I didn't have fuel coming out the overflow (I had that before, oh yes, and I rapped on the carb bodies with a ratchet handle) nor did I have gas squirting up out that air jet on top of one carb.. so much better now but she won't rev without bogging down (idles OK) and also when I rev it, she pops fire out the carb throats. one of the sliders still seems sticky as it isn't fluttering like the others but they are all popping. I tried to yank the carb set but even with all the boot clamps loose she wasn't budging. I read something about a clogged pilot circuit causing popping out the carb throats and also read that stock the main jets are oversized and the pilot jets are undersized - and this makes them pop, But I have a gross problem as she wont even rev. Is there something I can do without pulling the carb set? (seems they are stuck on there good and I bet difficult to get out and back in and I was even having trouble getting the throttle cables off!)