fuel mixtures

After putting in new shaft seal, fuel rail seals, and fuel mixture seals, (to fix a gas leak, bike was running), bike would not start. Thought maybe a weak starter, so pulled off, cleaned, put back on. Starter now sounds really strong (originally thought it might be spinning backwards because of the difference it made), but all I got was a sputter. So, pulled carbs back off, checked and wet set floats again, still same thing. Pulled carbs BACK off bike AGAIN and checked pilots. Two were clogged, so I think that might be the culprit. So, now somewhat unrelated, I cant help feeling funny about the fuel mixture screws, because #4 is the only one I see that the needle of the screw is actually coming through while I cant see the other three at all. Is this a normal #4 thing, or is something amiss. Just was wondering in the hopes of saving an unnecessary carb removal...........again. Thanks guys.

P.S. I have posted about this issue before, but no answer, so sorry for being redundant.

 

You might want to pull those pilot screws and carefully inspect them.

It's not uncommon for them to have their fine tip corroded or literally pulled clean off. Did you replace the tiny o-rings on the pilot screws?

 

yeah, I replaced them. The screw look fine as far as I can tell. If I switch them, the results do not change. Its always #4 going through when bottomed out. Im thinking I may need to tap them. Like 1-3 are incorrect or perhaps just gunked up. Nothing obvious but it is very hard to see in there.

 

Carefully examine the tips of the pilot screws. Compare them. Compare them to the one in the first pic here: http://xjbikes.com/Forums/viewtopic/t=31061.html

Be sure they all still have their very fine, pointy tips.

Then flush out the pilot passages again. Shoot some carb cleaner in there and let it soak. Flush again.

Did you do a nice accurate bench sync?

It's easier to use the holes in the top of the carb throats compared to the edges of the butterflies than it is to use "feelers" of any sort to bench sync Mikunis.

 

I am doing the same rebuild right now on my carbs...when reinstalling the pilot screws, the o ring and washer fell into the pilot screw hole and reversed their order. I decided to go back and check the first three I did and two of them were the same way. Easy enough to check...pull the pilot screw and the spring and see if you can see the washer, if you see black, the got reversed. Just a thought, don't know if it would prevent the bike from starting or not.

 

Yeah, I benched by the little port holes. My mix screws looks just like the one in picture, except I don't have any washers/spacers on any of them. Just the new seals. I'm guessing that they are important. Unless they were already switched and are trapped in the bottom, I don't think they were ever there, even when the bike was running. I already put the carbs back on bike and still no go. Mush your lips together and blow, and that's what my bike sounds like. I put gas in the tank a month and half ago, and today I noticed a dark amber color. So drained all the float bowls, hooked up my auxiliary tank (a #2 plastic jug), and refilled bowls with gas that I have for the mower. A lighter amber color. Still nothing. So pulled plug, dipped just the tip in the gas, grounded it and tried to start. Gas didn't even flare up. Bad gas? Not enough spark? All I know is it was running great until I replaced throttle shaft seals, fuel rail seals, and the rubber seals for the fuel mix screws. I will pull the rack again, and do as instructed by Fitz and look for the elusive washers and that are in correct order. Thanks guys.

 

I think checking the o-rings and washers would be my first order of business. It they are correct and all the needles are identical, then perhaps a po tightened the pilot screw too much and widened the hole of the one that is sticking out, or even damaged it with some sort of prob.

 

Ok, here's where I am now. I decided that since two of my pilot jets were clogged last time I pulled the rack, who knows what else got nasty. So I pulled them again and everything was still good save the enrichment tubes. At least I think so, because I found the corresponding holes on the bowls were clogged on the same two that my pilots were dirty. So I got the bowls cleared up again, but I'm not sure how to tell if the tubes are obstruction free. Any advice? I,m hoping that is my main problem with starting. As far as the mixtures, how crucial are the missing washers, and if I wanted to get them tomorrow, what size should they be, and what material? I have the threads on carb body soaking overnight, per fitzs instruction. Thanks guys for helping sort this out

 

Order them from XJ4Ever and get them in a couple of days. Better to have the right stuff than to repeat the procedure 6 months from now.

HCP895SET4 Aftermarket Hitachi idle mixture screw O-RINGS, set of 4:
$ 5.95

HCP896SET4 Aftermarket Hitachi idle mixture screw spring seat WASHERS, set of 4:
$ 6.95

 

He has a 550. It is Mikuni-equipped; but XJ4Ever will have those parts too.

I agree. The washers aren't any sort of common size; they're more of a "part" than just a washer.

 

.........fine......... jk, but will do. And the enrichment tubes? I tried to run a very thin wire through and it feels like it hits a slope or bend. Should I be able to shoot some cleaner somewhere to be sure they're clear?

 

Never mind. I just removed the plungers, and true to the rest of my mikuni experience, they were clogged up as well. I just ran my wire through and a few shots of carb cleaner, and success. Now, I'll just double check floats wet setting, order the washers and button up. Keep you posted. TY

Hmmm. Maybe I need a better fuel filter.