wolftlb Posted March 16, 2009 Share Posted March 16, 2009 Hello I'm from ohio, (long story) I just got a xs400s and it is in good condition but as I went to pick it up (from a preacher none the less) he pulled me off to the side and said he just made some mods that would really get some power out of it . Took it around the block and all seemed great so I paid for it and took it home. After about 6-7 miles I noticed it started to backfire alot finally chugging all the way I got it home and noticed it was really hot and would not start until it was cold then it acted fine again for short distances only. Two weeks ago I was about to give up and sell or junk it then my neighbor walked up to me and said he would check it out at this point I just gave him the keys and told him to have his way with it. Next day he comes over and tells me I had a too rich of a mixture, really huge spark plugs and gunky carbs. that he fixed. Now it runs good I can drive it till it runs out of gas and after some paint looks like new. I visited the preacher and asked him what other mods he made and he said the only other than than what I found was he drilled in to the muffler (bored out the baffles i guess). (short story) What I was wondering is is there any thing besides replacing the muffler that I should do to help with the bored out baffles any carb settings because I have heard of this trick before. Also if I'm cruising at say 50 and gun it it will bog out and slowly creep to 65 but I have no problem slowly getting there P.S. Could anyone point me to a good carb. syncing tutorial my neighbor has a homemade carb sync that i would like to get done. Link to comment Share on other sites More sharing options...
KFunk Posted March 16, 2009 Share Posted March 16, 2009 heh, where in Ohio? I'm gonna guess the Zanesville area. I'm down in Athens myself, and had this on my bike when I bought it: I cant help much with the other stuff myself, since I'm fairly new as well. But Synching is easy. You just need to use the screw that connects the throttle linkage on the two carbs, and adjust it until both carbs are sucking an equal amount of vacuum on both (i.e. the throttles are open at the same position on both). There's a thread a few days back on making a synch tool with some tubing and a yardstick, and that worked for me. You've gotta connect the hoses to the vacuum ports on the top of each carb. Since the one is needed to operate the fuel petcock, you'll have to find another way to get fuel. Some people just connect a hose to a separate bowl of fuel. But I just set the petcock to 'Prime' and wiggled the fuel tank to the side to give me just enough room to access the synch screw with a stubby screwdriver. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted March 16, 2009 Moderator Share Posted March 16, 2009 for carb tuning try HERE Link to comment Share on other sites More sharing options...
wolftlb Posted March 16, 2009 Author Share Posted March 16, 2009 Well I did some searching and I guess drilling the baffles just changes the sound and maybe adds a couple hp but not a major problem. the bike still coughs every once in a while especially when I go through the trailer park at 5-10mph(sometimes so hard it jerks the bike and almost kicks me off). Every once in a while cold or not it hangs at 3000 rpm and slowly recovers I turned the idle back to its original 1200 rpm and it does not do it as often. Also all you diy painters how many clear coats did you put on your tank my neighbor said he put about 5 then a coat of liquid glass and I must say looks better than some bikes in a showroom but seems like over kill to me. I would just like to have this bike in top shape in a week and a half because my boss wants to go out riding with me and I don't want to be left behind ( or worse call for a pick up). Any tips on restoring and maintnace ( or things to look for to un-hillbillify ). The engine sounds a nd pulls great so I don't think I'll be digging too far in to it as of yet. I love working on cars also rebuilding 76 torino but this is my first experience with a motorcycle so im almost lost!! Btw kfunk I'm from clothesline I mean Crestline . Thanks for the reply drewpy. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted March 16, 2009 Moderator Share Posted March 16, 2009 clean machine and looks good Link to comment Share on other sites More sharing options...
wolftlb Posted March 17, 2009 Author Share Posted March 17, 2009 Thank you drewpy that is just the start though ! does anyone have there exhaust painted if so can you post a pick I would like to cover the ugly exhaust sealer they put on. also as i am sitting on the bike the right vacuum line is capped off should this lead to some where. Link to comment Share on other sites More sharing options...
KFunk Posted March 17, 2009 Share Posted March 17, 2009 also as i am sitting on the bike the right vacuum line is capped off should this lead to some where. Nah, as long as the other one is hooked up. One of the two vacuum ports should run to the petcock, which serves to open and close it (its a safety measure to keep you from dumping fuel into the bike while not running). The other vacuum port should be capped off, but will help you with synching the carbs. I would say if you don't want to embarrass yourself with the boss, then ride the damn thing as much as you can between now and then. You'll soon find out any problems. And have you ridden motorcycles much before? Just be sure you're used to the bike and don't stall it or stumble and drop it for some reason. Link to comment Share on other sites More sharing options...
wolftlb Posted March 18, 2009 Author Share Posted March 18, 2009 Well coming alone with it just fine thanks kfunk for the quick answer. Going to sync carbs this weekend maybe paint the tank (unless its nice then I'm going to ride it ). this is my first bike I road my dads Honda shadow 650 so I'm quite comfy with motorcycles. The breaks are squeaking now don't see anything in the front so I'm guessing its in the drum. I have no experience with tire and alignment haven't looked to see if I have to take it off in the first place so is there any tips I should know. I'm also taking off the front. If anything I''l stick to the manuals but I like to hear from ppl with experience. Thanks to everyone that is helping I hate joining new forums to find out they are full of jerks . Link to comment Share on other sites More sharing options...
78XS400 Posted June 30, 2009 Share Posted June 30, 2009 Good luck they are fun bikes, I am still working the tweaks out of mine, mostly the dang carbs but I think I may have them right I just need to properly sync them, does anyone have the how to using the line and atf fluid? I think we both could use this... Link to comment Share on other sites More sharing options...
derelicte Posted July 3, 2009 Share Posted July 3, 2009 Sorry to threadjack but do the squeaking brakes indicate worn pads? I know that most pads on newer cars will squeak once they reach a certain level of wear, but was wondering if this applies to older bikes like the xs400. The front brakes on mine squeak a lot. Link to comment Share on other sites More sharing options...
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