armyofda12mnkeys

12v10w is right... but they don't have the 'right' version . So what would happen if i put that 14.4V 1.8W* in instead? Would it try to suck more juice causing problems or just be dim.

curious my bike's turn signals have single filament 12v 10w lights in them. Pep Boys only has 14.4V 1.8W lights... Will these work out?

hah i guess MikesXS does have everything. This was first time i saw a part i thoiught they didnt havve Thanks!

Hello all, I'm looking for the lil screw-in jet on the left side on the back of the carb. I think its different than the 'pilot jet' which is inside the carb.... This is called the 'air pilot jet'. I think the values on that hole are 170 when i looked at it (but on backup carb i have I think i saw 155), not sure whats stock. I think the 'air pilot jet' is #52 here (vs #12 for the 'pilot jet'): http://www.boats.net/parts/search/Yamaha/Motorcycle/1978/XS400E/CARBURETOR/parts.html I think my is a bit stripped so i was looking to replace. MikesXS has 'pilot jets' but i didnt see 'air pilot jets' Thanks!, -Arian

PS is this the missing washer you thought wasnt there drewpy? Its recessed into the carb main jet hole on both sides. Seems like should be there? So its under the Main jet screw... but i guess you were talking about the other screw in first pic i posted (aka #13 in diagram vs #10 which is Main jet screw) Anyway let me know if i still need a washer under that screw .

thanks! I forgot about MikesXS BS34 parts . I have an extra carb I'll use as a backup from a 77 thats just as nice. Ive opened it a few times with no problem with the float gaskets as they are pretty thick/tough. My electric ignition xs400 cafe racer ran well the first year, thanks again to kmac and drewpy for helping. Im gonna maybe ask someone to weld some custom brackets for some new Dyna Coils i bought, as kmac figured the correct coils to use and seemed to run well.

cool , where do you buy the washer? i saw it discontinued if its item #11 on diagram: http://www.boats.net/parts/search/Yamaha/Motorcycle/1978/XS400E/CARBURETOR/parts.html

hah, interesting.. would there be any side effects of a missing washer during bike operation? Also would you suggest removing the black round gasket? it was on both 1978 XS400 carbs, but then again you have the same bike I remembered, so If you dont have it and the bike is fine. Then I can get rid of it i guess -Arian

Just curious, i lost one of the rubber 'round' gasket part that goes behind the Float Gasket... Pic attached... I didnt see it anywhere on yamaha's offical parts: http://www.boats.net/parts/search/Yamaha/Motorcycle/1978/XS400E/CARBURETOR/parts.html Is this part terribly important and if so, where do I buy it ?

>have you changed the idle jets didnt change the idle jet, didnt think the air filter was that crazy of a mod that it can't at least run 80% of its former glory and idle fine. I did see DimeCityCycles has 2 sizes for these cb idle jets. I could get one i suppose but i doubt thats issue. it was kinda running the same way before upgraded air filters/cleaned carbs >it could be the carbs haven't been cleaned properly. hmmm i cleaned the carbs i thought well, maybe i'll take another look. what specifically would cause that pocket of air to be forced backwards like that?

I asked on dotheton, but just thought I'd ask here too since Yamaha folks have always been great. My friends '74 cb450 had a variety of issues. I had to clean his carbs as his bike started to run bad, and he let it sit for too long which gunked up carbs. We then put on uni-filters since his stock air filters were breaking up, and we put a higher main jet for that air filter. Bike starts after 5-10 kicks, but stumbles/splutters. Idle mixture doesn't seem to help at all. Bikes symptons are: 1. Backfires occasionally out of right exhaust. Sounds like a gunshot hehe. (read that lean or rich conditions can cause it, but idle mixture seems to be fine). 2. Has a noise coming out of right air filter. We took off air filter and see some air is pushed back to air filter (splats a lil' gas droplets back if you put your hand there). 3. While engine is weak at startup, if you give it some throttle it may not cut off... if so, after riding for 5m, it may have high idle. Bike rides decent in 3rd gear giving throttle, but at the lights, it stays at 3k rpms. I am guessing timing? like maybe intake opens at wrong time and forces air into carb?, and exhaust opens at wrong time, causing un-ignited gas to hit the hot exhaust and ignited there? Exhaust is hot, so gas is ignited most of the time it seems though. Used a Colortune sparkplug to confirm that gas is igniting on that side (didnt pay attention though if it was missing ignition during those exhaust-gunshot or carb-intake sounds).

I saw one video where they had wires going around each prong/input on the relay (of a car), and then they plugged it in (so each wire still stuck out and could be tested). And then he tested each of the wires for continuity... Would this pretty much be the same for testing my relay? For voltage drop testing... should each of those prongs be tested (3 prongs on the flasher relay), or only one is really needed to test?

well i think theres a way to specifically test the specific device you want (my flasher relay) ... vs just reading the battery. I'll figure it out in next few days, got a book on voltage testing. Anyway the values of just the battery were as follows: (ps bike never actually started, just ignition turned on (no engine) in following tests) motorcycle off: 12.78v (seemed to rise slowly from 12.74 over next minute) motorcycle key ignition on (light off): 12.45v motorcycle key ignition on (light off) + put kill-switch to Run: drops to 12.35v and bounces back up to 12.45v motorcycle key ignition on + put kill-switch to Run + turn light on: 12.33v motorcycle key ignition on + put kill-switch to Run + turn light on + turn on left signal: 12.31 cancel signal: then goes back to around 12.32 motorcycle key ignition on + put kill-switch to Run + turn light on + turn on right signal: 12.31 cancel signal: then goes back to around 12.32 think above test didnt help much.... need to test if that device itself is getting all the power it needs? it may just lose resistance through a frayed cable and you wouldn't know about it unless u tested that device right, as the other devices in parallel will use up their 12v and return 0 back to ground, and wouldnt neccessarily know about that flasher unit? think i need to test positive side of that unit, aka hook positive to positive of battery and negative to one? of wires the input of the flasher relay unit. and then test the ground side to make sure it used up almost all the Volts it was given.

I wanted to just test and see if my turn signal flasher unit on my 78 XS400 is getting the power it needs. I was reading about voltage drop testing ... How can I voltage drop test this device? ... Do you have to cut into the wire going into it and out of it to measure it, or can you somehow do it without cutting into the wires (i assume so)? Thanks for any advice

Hey Guys, I was taking my spark plug out to read what color it was after having it running for a few minutes ... and when i pull the plug out, I see some smoke lightly come out for next minute or so... just a light white smoke gently streaming out. But I never seen anything ever come out of the plug hole when I took out my plugs to read them (and Ive done this about a 100 times). Just curious what it could mean ... I probably still have some SeaFoam left in the gas if you think it could be SeaFoam 'burning' off hehe. -Arian