.jpg.5c05eb7af257e741ca000bd984024429.jpg)
drewpy
-
Posts
15,169 -
Joined
-
Last visited
-
Days Won
295
Content Type
Profiles
Forums
Gallery
Events
Yamaha Racing News.
Media Demo
Store
Collections
Classifieds
Posts posted by drewpy
-
-
I have just put my xs400 back together and the problem I thought I would have solved by cleaning the carb is still there.
What is happening is that from idle to about 3500rpm to 4000rpm it has no power whats so ever and once it pass 4000rpm it is fine. None of the jets where plugged or damaged. The bike idles pretty well but I cannot figure this one out. Does anyone have any suggests?
Thanks inadvance.
Stu
your pilot system is blocked or way out of adjustment.
mains take over around 4k, i had to have mine ultrasonic cleaned in the end
-
Just wandering if anyone knows, I need to source some parts for my '79 xs250 but that is proving quite difficult. Mainly i need a right hand exhaust (just the end can) but i cant find one anywhere. Parts for the 400 are easier to find, i was just wandering will the parts (exhaust) off a 400 fit my 250 and will it alter the power dramatically (good or bad). If anyone can help me that will be greatly appreciated.
Cheers in advance,
Chris
OEM exhausts? forget it I had to buy a 3n6 version (nearly the last one in the world!!). the only way to go is sito, there is a distributor
http://www.vyxxn.co.uk/ need to email them for prices and availability.
I use motoward, cmsnl, speed sport, bike bandit, pgm (really RD aircooled but the 400D shares a lot of stuff)
400 is the same as 250 except for smaller bores and carbs and associated parts. get a parts book from ebay and that will help you identify the commonality.
if you do find a new right oem exhaust (1U4) let me know
-
Thanks..
Will something like this work?
why don't you ask the vendor, its that the xs400 needs 12v for the charging,it may have enough in the capacitor to start the process.
-
Thanks for the replies fellas. So, i want as little wiring as possible, but what do i need to run the bike without a battery? I will need to wire the regulator from the alternator and use the condenser right? I will not be using the wiring harness anymore, I will be making my own because there will not be alot to wire up and i will be running some of it internal. Thanks again
the charging system needs a 12v supply to work.
here is a wiring diagram
could try this
http://www.zeeltronic.com/page/bat_elim.php
let me know if it works
-
Hello all, new to the site. Just wondering if any of you nice folks here could help me out. I am building a cafe racer out of a 77 xs400 and wondered if anyone could help me out with wiring it up for kick only application. I have all of the stock components, and the bike runs well using them. Anyone got some diagrams or suggestions? Thanks in advance!
Take out the starter motor and chain (saves a few LBS) as the xs already has kick start, you don't really need to do anything else!
If you're really finicky you can take off the starter solinoid from under the seat. As Merv said you coud use an rd right hand switch gear and polish up the casings as they are alloy!!
-
i'm looking for the wiring diagram for the 1975 rd250 (USA model). can anyone help? thx!
try http://www.aircooledrdclub.co.uk/forum/ and do a search
-
-
the pilot system affects the lower rev range to 4k 'ish and the mains take over.
The galleries in the carbs are very small and even after i cleaned them they were still blocked. that is why i ended up sending them away to be cleaned.
the reving you encounter is a weak mixture in the pilot system, but any tweaking of the screw will not overcome the reving. BTW its 1.5 turns from the bottom.
Another fault i have found is the pilot screws snapping off at the bottom due to wear of the brass and hamfisted tighteneing (an interference fit into a conical seat) you can check by completely removing the pilot screws and they should have a really fine needle on the end, if they are "dumpy" ie rounded then the end has snapped off, this has happened on both sets of carbs i have had!
the float height is very important:-
yamaha say 26.6 +/- 2.5mm
using a venier caliper, measure the distance of float arm from the top of the float chamber gasket seat (no gasket) to the top of the float. (the float should be resting on, but not depressing the spring loaded inlet needle)
bend the tang to achieve level amont
both right and left floats have to read the same.
Drewpy
-
Hi folks!
I've found a nice old XS360 for sale, but it does need some work on it. Doing the work doesn't stress me but, am I going to be able to get the bits? And, if I can get them, will the price give me heart failure!
I know it will need mufflers and pipes and a seat. I suspect it will also benefit from a rebore and top end overhaul, so getting oversized pistons, rings and gudgeon pins is likely. Add valve cotters, timing chain and gasket set to that list too.
Anything specific I should watch out for with a 360?
I expect it will also need new tyres soon. Any ideas on what suits it best? Best, IMHO, is that which sticks to the road like glue!
genuine exhausts are almost unobtainable now, but sito are available as well as motad 2 in 1's and MAC in usa.
Need to check out cmsl.com for parts and speed sport in usa! as I am not too sure regarding the 360 (might be able to use 400 pistons etc.
best tyres are BT45's, the rd boys swear by them.
drewpy
-
I just replaced the two boots from the motor to the carbs. They were severly cracked. I thought that was the problem. I'll clean out everything I can tonight and check that out. It ran great except for a clicking noise in the carb area last year. When the choke is on it doesn't make the noise. Once it is warm and the choke is off it barely runs. Thanks for your in put.
sounds like a blockage, do you use an inline petrol filter?
-
Can someone reveal the truth behind my XS750 having 2 petrol taps??
far as i know its to supply enough petrol for the carbs and the way the tank sits on the frame!
-
I don't recommend soaking in solvent as there are rubber bits in the choke mechanism. what you need to do is get them vapour blasted ( for looks) and then ultrasonic cleaned. I use jrs in Uk but you will have to do a google search if your in the USA.
these will come out ultra clean and JRS even replaced the parts of the carb with my keyster kit and built it up for me! approx £100 for ultrasonic clean.
-
sounds like the swing arm bushes have gone, you can check by the sideways play on the swingarm 1mm max (is on my xs400)
the electrics on those bike had a reputation along with the cam chain.
I agree that they are great looking bikes, the 850 was the updated 750 with all the niggles sorted.
have a trail through the old forum via the search system as I'm sure that someone has asked the same question.
BTW check the middle gear box oil as that gets forgotten at service times!!
-
If the vaccum gauges do flutter, there is a knurled knob on the pipe which needs tightening up till the fluttering stops. this acts as a damper due to the engine characteristics and is normal on all bikes.
checking my manual, the carbs are the same as the 400 but have different sized jets, so you need to ask them for a 360 kit.
the 360 has; 135 mains, 0.6 air jet, 4FP21-3 jet needle, X-6 needle jet, needle position 3, pilot jet 17.5, starter jet 40.
air screw 1 to 1.5 turns out from stop.
send them an email, as they have tons of stock. if they don't have any try NRP in Manchester UK!
-
Those are the carb kits, in fact the exact same ones I bought. Don't forget you need two!
The valves are really easy, just use your manual to set the crank to the timing marks and 10mm spanner and feeler gauge.
rtv on the inlets is not a good idea, use a gasket and check rubbers for cracks/splits
-
WOW some text
1) Sounds like air is getting into the inlet side of the bike. Spray some wd40 around inlets and listen for any engine revs which would iindicate a leak there
2) you need to get a keyster carb kit and replace everything with the kit
3) tune the bike by setting the valves, points gap, timing and finally balance the carbs. If you get the vaccum guages there will be instructions in there. you need to find a way of supplying fuel with the tank off the bike and you use the stubs on the inlet rubbers as vaccum take-off.
hope this helps
-
thanks for the info , just to check that a 400 will fit in this , right ?
Looking at your bike....yes with no mods.
-
will an xs400 engine fit a xs250 ?or even can the 250 be bored out by much ?
it needs new piston rings any way so might as well bore it out / get 400 bores put on the 250 engine and put all new pistons on it.
I assume your talking about the 2A2 engine, as there was a later dohc engine which won't fit.
the xs400 will slot straight in and is in fact lighter than the 250 (bigger bores I assume) you can't just overbore as the valves are a lot smaller and uses a different carb 32mm-250 34mm-400.
I think even getting a 400 barrel onto a 250 bottom end could cause the liner to foul the crankcase mouths (not tried it, but i'm guessing)
I bought a 400 engine off ebay for £50 and carbs for £20, then you need the rubber between each side of the carbs for the bigger mouths. Well worth the hassle though as mine motors up to 85 and great on the twisties.
a custom model will fit as its only got a rounded barrel as opposed to a squared off one. Be careful of the 12n model as they have "rear sets" which If yours hasn't then you need to figure this into your equation.
BTW loads of stuff in germany, but be carefull with carbs and camshafts as they have restricted (27bp) engines
drewpy
-
take ya time soak it up, tell me what ya think
I'm thinking;
Flying time and CAT B write off
-
I have an 83 xs400 hasnt moved for years (since 91) but has been garaged and is totally standard and complete.
Do i keep it and make it new again or take the £200 ive been offered ?
I wouldnt normally ask but im a honda man not yamaha but i like this one. Is it a classic ?
Go for it, if you like the bike its gotta be worth it. over 15 years old is considered a classic nowerdays!!
-
Have you tried ultrasonic cleaning?
I used JRS and cost £100 for a pair to clean.
-
Hi guys seen that on bikes that are used for racing and track days that people have put the suspension forks through the yokes in order to lower the front end - what benefits and disadvantages does this give the bike as im looking for more cheap mods to do to the bike.
Regards
quickens the steering at the expense of high speed stability
-
-
you will need to remove rear wheel, remove air valve to release any remaining air, then with a set of tyre levers/irons, start to lever the tyre over the rim,start at the valve, when you have removed on side remove tube, check inside of tyre for any foreign objects, I:E the screw ( do not omit to do this i once found 27 thorns in a tractor tyre )
fit new tube put tyre back on opposite valve then work it back over the rim, you will have to lever the last bit back, now here is the trickey bit be very careful levering the tyre back it is very easy to trap the tube between the rim and iron/lever as you put it back on,
mervin
don't fortget to break the seal first on the rim. I run my car over the tire slightly and you can hear it crack. otherwise you can't get a lever in.
fuel line help
in Classics
Posted
Hi,
thought you had the carbs sussed!
1) the petcock has one supply from the bottom outlet going to the left carb
2) the connector at the back of the petcock goes up underside of the tank and to the right intake. this is the vaccum to operate the flow of petrol (gas)
3) there is a pipe link between the two carbs at the back, just above the float bowls, it also acts like a support between the two carbs so could be misconstrued as such, but is in fact the supply to the right carb.
there's lovely for you!!