Moretto Posted September 11, 2006 Share Posted September 11, 2006 Hi there! My first problem is the choke. It is just not working. Cold or hot, the engine stops if i even touch the choke lever. Guess that the mixture is too rich, however, as I don't have any kind of user or service manual, I don't know how to adjust it.. A new problem came up today, as I parked in front of a store, I came out and there was gasoline under my bike! Tried to start it, no way. I closed the gas, waited for a few minutes, and it started on the last drop of battery power. After a while, it revs ok, no more leaking....seams ok now. Could it be dirt in the carb, under the float needle?? Can I clean the carbs myself? Its two Mikuni carbs..are they complicated?..I rebuilt my Vespa's Dell Orto, a few Fiat' s Webbers and a Opel's Varajet. Am I qualified?? Link to comment Share on other sites More sharing options...
BrewTrooper Posted September 13, 2006 Share Posted September 13, 2006 Moretto, I have an XS400 and I recently "rebuilt" and cleaned the carbs because it sat for over 11 years. I had never looked at a carb before in my life. Yamahead helped me out and now I'm willing to do the same. PM me if you want help and some links to photos and some "how-to" information. The problem with your choke sounds like it is related to the choke circuit in your carbs and they could be blocked. If so, a cleaning would help. The fuel leak is not good. Were you able to track down where it was coming from? You have to be careful that the fuel was not leaking into your combustion chamber. If so, it would leak down into your oil and break it down. That would definitely not be good. If the carb floats are leaking, I highly recommend servicing them. What year is your XS400? BrewTrooper (a.k.a. Ken) Link to comment Share on other sites More sharing options...
Moretto Posted September 14, 2006 Author Share Posted September 14, 2006 Moretto, I have an XS400 and I recently "rebuilt" and cleaned the carbs because it sat for over 11 years. I had never looked at a carb before in my life. Yamahead helped me out and now I'm willing to do the same. PM me if you want help and some links to photos and some "how-to" information. The problem with your choke sounds like it is related to the choke circuit in your carbs and they could be blocked. If so, a cleaning would help. The fuel leak is not good. Were you able to track down where it was coming from? You have to be careful that the fuel was not leaking into your combustion chamber. If so, it would leak down into your oil and break it down. That would definitely not be good. If the carb floats are leaking, I highly recommend servicing them. What year is your XS400? BrewTrooper (a.k.a. Ken) Hi BrewTrooper. My XS 400 is 1988. It's a DOHC in almost perfect condition, with original 18 000 km, so one would guess that it sat a lot. It was leaking through the air filter casing, and for sure in the combustion chamber, but it didn't happen again. My guess is that it was some dirt blocking the float or the needle-valve in one of the carbs. I pushed it hard for two days...it seems OK now, even the choke works up to some point (goes off if i pull the choke full). The more I ride it, the better it works.. I am thinking of giving it a full service as soon as the weather goes bad...In my country(Rijeka-Croatia)..if there's no too much rain, it goes cold after New Year. Until then I was hoping to enjoy it for some time. The oil viscosity seems to be OK, and the oil level did not change, so I guess that the gasoline did not have enough time to leak so much..it was for a few minutes while I went to the shop, and as I mentioned before, it didn't happen again. Anyhow, I was thinkong about authorised service, because I am mostly concerned about sincronizing the carbs after cleaning..it takes manometers and some experience...i guess...but if I decide to do it myself, Your help would be most appreciated. Moretto(a.k.a. Mladen) Link to comment Share on other sites More sharing options...
BrewTrooper Posted September 14, 2006 Share Posted September 14, 2006 Moretto, If the bike did sit for a while, you'll definitely want to clean the carbs. If you can afford to have it professionally serviced that is good. If you do it yourself you could save some money. It's really not that hard, and you'll learn much about how your bike works; and you'll have the knowledge to do it again in the future. I wouldn't worry about the synchronization unless you think that someone messed with it. Otherwise, it should be fine if you clean the carbs. I recommend replacing the float valve assembly with O-Ring, Carb rubber passage Plug, & Float bowl Gasket. You can get the rebuild kits for $12/each (U.S. $). If you can't find a cheap source, let me know and I can help you get them. Good luck, BrewTrooper (a.k.a. Ken) Link to comment Share on other sites More sharing options...
Moretto Posted September 15, 2006 Author Share Posted September 15, 2006 Finally found a manual! On a Russian website. A service manual in German language. I didn't mention that the previous owner had no manual at all. I was searching for a user's manual, but this is way better. You were right, the carbs don'seem so complicated...i guess I can do it myself. Link to comment Share on other sites More sharing options...
BrewTrooper Posted September 16, 2006 Share Posted September 16, 2006 Congratulations on the manual. You can also check out this site. It has a lot of nice full color picture of the whole breakdown. Also, the carbs used are almost identical to yours. Carb Rebuild Pictures Good luck!! Link to comment Share on other sites More sharing options...
Moretto Posted September 16, 2006 Author Share Posted September 16, 2006 Congratulations on the manual. You can also check out this site. It has a lot of nice full color picture of the whole breakdown. Also, the carbs used are almost identical to yours. Carb Rebuild Pictures Good luck!! Thank You! Veeeery useful info. I went through the german service manual, also helpfull piece of documentation, only for every word longer than 20 letters (like "hinterraderlagereinleitung".......something)I have to send a SMS to my friend in Frankfurt to translate it I have greased and oiled all the parts that needed it, on my surprise nothing was blocked, but the clutch lever dos not go smooth even after greasing it...have to check it some more Link to comment Share on other sites More sharing options...
Moretto Posted September 22, 2006 Author Share Posted September 22, 2006 I decided to leave it to a proffessional. He fixed the carbs for about 50$ US. Changed the gaskets and cleaned it, it was dirty, but everything else seems to be OK. It has only about 18500 km now, so he expected that. Guess I could do it myself, but ...as we say: give the baby to the mother, she knows best. I have another little problem. The clutch lever does not run smooth.When I squeeze it quickly for shifting, it's ok, but if I squeeze it slowly, like it stucks to something. Feels like the cable is rusty or damaged, so I put a new one and greased it.It doesn't solve the problem, so I think the old one was OK. Any experience on that metter? Link to comment Share on other sites More sharing options...
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