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VF AAR
11th September 2007, 10:20
Hey guys and gals
I recently bought an 87 vfr400r
Before all this its hadn't started for a year.

Its got brand new oil and filter and plugs

When I try and start it, theres no spark. so I did what every other d.i.y dude would do, test the plugs.
They all earthed out to the frame fine, beutiful spark.

I've been told when bikes sit for ages the carbourators sieze up. so i sprayed a whole can of carb cleaner down the carbs. still nothing

After removing the side covers it seems there is petrol in the engine oil.
which is strange considering i put brand new oil in it. (i'm assuming when i was trying to start it the litre in the tank completely pumped itself into the engine)

the bike turns over freely but wont start.

Any ideas? carby blocked or stuck open causing it to flood?
Have good petrol supply and on/off/res switch isnt blocked.

Any help at all would be appreciated.

Cheers!
if you wanna flik me a txt 021 0666 306

mogiman
11th September 2007, 23:39
you put fresh fuel in it had the same problem with an fzr 400 i had,had me stuffed for a whole day the fuel even had smell to it as soon as new fuel went in bang...just to be on the safe side turn on the fuel tap lol
also on my 87 gixxer the oil filled with petrol one of the floats was out so over night filled the oil with petrol ,
it may be the diaphram (excuse my spelling)
in the fuel tap if i remember correct my vfr had this prob so the fuel wasnt running under vac pressure and just flowed out..
just a couple of possibilities

VF AAR
12th September 2007, 09:55
Yup fresh fuel was used, 95octane.
The fuel tap was blocked, so i just removed that diaphram thing and resealed it so when its on, its supplying heaps flow.
What I didn't understand was while I was trying to start it the bike drank about a litre of gas into the engine.
Then I removed side covers and there was heaps of petrol in the oil. so it must have gone in there from the gas tank because it had brand new oil. (This couldn't have happened overnight as I had the gas tank off the bike, so it happened during the attemps to start it)
Does the fuel have to run under vac pressure? would explain the flooding

Still havn't sussed it aye. Should really just put her in the shop

mogiman
12th September 2007, 11:16
Yup fresh fuel was used, 95octane.
The fuel tap was blocked, so i just removed that diaphram thing and resealed it so when its on, its supplying heaps flow.
What I didn't understand was while I was trying to start it the bike drank about a litre of gas into the engine.
Then I removed side covers and there was heaps of petrol in the oil. so it must have gone in there from the gas tank because it had brand new oil. (This couldn't have happened overnight as I had the gas tank off the bike, so it happened during the attemps to start it)
Does the fuel have to run under vac pressure? would explain the flooding

Still havn't sussed it aye. Should really just put her in the shop

Diaphram is important it stops the fuel just flowing other wise it just runs straight through ya carbs to the top of the cyclinder runs past your rings and into your oil they are pretty cheap if i rem correct and the vac is important too made that mistake runs like crap otherwise
my ph# is 0211830405 if ya really stuck got no credit at mo so cant replt to text or text

VF AAR
12th September 2007, 12:14
Ha! that makes sense!
Maybe the fuel tap wasnt blocked at all it just needed vacuum to open it?
I'm assuming the pipe that comes off the outlet of the fuel tap provides vacuum?

So I grab some new oil, drain the crap out, put the diaphram back in and hope for the best?

Still puzzled as to why it wont start though...
Any ideas about the electrical side of things that I should try after I suss that gas issue out?

Points seem ok
Earthed plugs to frame and they earth out good
doesn't doing this ^^ mean your plugs/leads/coils/points/ are all go?

Would hooking a car battery (12v) up to the bike battery (12v), then the bike battery to the bike.. ruin anything?

Mate you've made my day aye I thought I bought a LEMON

HenryDorsetCase
12th September 2007, 12:48
I think i had a similar problem with mine recently (not enough vacuum to open the fuel tap, no fuel = no run). then when I fixed that I flooded the thing senseless... I did the HRC fuel tap mod (http://www.akhara.com/nc30/fueltapmod/index.html) to mine.... you have to be careful after doing the mod that the only diaphram left in the tap doesnt leak but other than that it takes about five minutes. dont forget to crimp or blank off the now un needed vacuum line...

are the spark plugs stupidly expensive where you live?

and thanks for the reminder re the oil. I didnt check mine after I had all the issues. at one point I was squirting fuel out of a squeeze bottle down the bellmouths... so some is sure to have gotten past the rings.

mogiman
12th September 2007, 13:21
Ha! that makes sense!
Maybe the fuel tap wasnt blocked at all it just needed vacuum to open it?
I'm assuming the pipe that comes off the outlet of the fuel tap provides vacuum?

So I grab some new oil, drain the crap out, put the diaphram back in and hope for the best?

Still puzzled as to why it wont start though...
Any ideas about the electrical side of things that I should try after I suss that gas issue out?

Points seem ok
Earthed plugs to frame and they earth out good
doesn't doing this ^^ mean your plugs/leads/coils/points/ are all go?

Would hooking a car battery (12v) up to the bike battery (12v), then the bike battery to the bike.. ruin anything?

Mate you've made my day aye I thought I bought a LEMON

spray some crc or something in your kill switch area as it might have some corrosion on the connections and check you havent disconected any of the plugs and i dont mean spark is it turning over ???if not also check your fuses .!!!

mogiman
13th September 2007, 16:16
howd it go did you get her started ???

VF AAR
14th September 2007, 11:51
Still not going, mean new respray black tho looks mean.
checked the diaphram back in andchanged the oil. fuels not by passing into the engine now and oils mint.

but still no spark.
I'm thinkn what mogiman said sounds about right all give that a go.


and there is fuel going into the carbs cos when i bleed them gas comes out, and ive tried it heaps just to make sure. so there is fuel going in, air going in, its got spark against the frame. but no spark in the chamber.

I just dont get it aye
gonna check compression this afternoon
in the specs it says its 11.3:1 compression.

Let you guys know how its goes..
cheers

VF AAR
14th September 2007, 12:06
Fuses are all good all brand new
Just read up on the net, some other nc24 vfrs have had the same problem and ended up being a faulty cdi.

Cheers for all the help so far aye I appreciate it

mogiman
14th September 2007, 12:10
gona be couple hundy from a wrecker ,so its turning over but not firing ????some cdi can be repaired and on tardme theres a guy who does aftermarket ones hyperpak his name type cdi in the trademe thingy guys got a nc21 cdi for 25 bucks bye now dirt cheap and a lot of things swap over from the different models not sure about cdi but you could do a quick check

VF AAR
14th September 2007, 20:41
Compression test came thru mint.
and kill switch is operating mint.

yup turning over but not firing. firing against the frame but not in the cylinder at all. checked all ignition connections and all that.

got me puzzled aye
Into the shop she goes first thing tomorrow.

FROSTY
14th September 2007, 22:19
dude just spraying the carbs through with carb clean aint gonna sort em.
Rip em out and clean out all the jets propperly.
becha itll go fine after that

VF AAR
18th September 2007, 10:31
^True i'll give that a go tonight.
I've tried taking the whole carb unit off but seems quite stuck on.

Test light test came through all good
cdi sweet
coils sweet
points sweet

Bike wont even run on; ether - engine start

What Idont get is if i can flood the engine with petrol
how come the spark wont frikn ignite that petrol.

meh

Paul in NZ
18th September 2007, 10:38
Are the plugs wet when you remove them? I ask because if there is gas in the float chambers does not mean it's getting into the cylinders.

Pull the carbs off and pull them to bits and clean properly. Blow all jets through with compressed air and check the diapragms.

A 100cc cylinder sucking air through those huge CV carbs means it has to be bang on or it won't fire.

VF AAR
19th September 2007, 09:41
I think i had a similar problem with mine recently (not enough vacuum to open the fuel tap, no fuel = no run). then when I fixed that I flooded the thing senseless... I did the HRC fuel tap mod (http://www.akhara.com/nc30/fueltapmod/index.html) to mine.... you have to be careful after doing the mod that the only diaphram left in the tap doesnt leak but other than that it takes about five minutes. dont forget to crimp or blank off the now un needed vacuum line...

i only had one pipe comming off the gas tank and thats the main one. it looks like there is ment to be more but there isnt.

i did that hrc fuel tap mod, its a good idea and makes sense but doesn't solve me problem

is there some sort of secret way the carbs come off or?
cos ive been yanking at mine for ages and it wont budge and ive undone everything that even looks remotely connected with the carb.

Ocean1
19th September 2007, 10:21
Can't help with the carb thing dude. But did you get new plugs?
Just because you can see a spark when it's out of the cylinder it doesn't mean it's good enough to work properly under pressure.

Paul in NZ
19th September 2007, 10:42
is there some sort of secret way the carbs come off or?.

Are they in the middle of the V? If so they could be joined on a pivot type arrangement that needs loosening off. Down load a manual if you can.


cos ive been yanking at mine for ages and it wont budge .

Yikes - that must be frustrating...

mogiman
21st September 2007, 16:48
how it going still having trouble ????

kiwi cowboy
21st September 2007, 21:58
The spark its generating wot colour is it.
I ask because i once tryed to help my boss get his v4 500 racecar going [pushed-towed thing for ages when we tested the plugs for spark against the engine there was plenty but we found out aftre taking it to a shop the spark was the wrong colour the spark was blue i think but neede to be orange to fire up new plugs and thing fired up fine hope this helps.
PS this wasnt on tardme was it

kiwi cowboy
21st September 2007, 22:07
Diaphram is important it stops the fuel just flowing other wise it just runs straight through ya carbs to the top of the cyclinder runs past your rings and into your oil they are pretty cheap if i rem correct and the vac is important too made that mistake runs like crap otherwise
my ph# is 0211830405 if ya really stuck got no credit at mo so cant replt to text or text

i have had the tank off my nc21 ive just got and the diaphram in mine is in so it gravity feeds strait to the carbs is this sposed to be in towards the tap and the carbs suck it past? i wondered bout this when i had it apart but didnt want to screw round with it.i do no it floods easly starting it will this be the problem cheers and sorry to highjack the threed:bleh:

VF AAR
9th October 2007, 08:18
Took the bike to Mt. Eden motorcycles on crner of boston and mt.eden rd
It was beyond me
$200 later the diagnostic
FLOAT NEEDLE VALVES need replacing and adjustig
i thought $200 for that was STEEP
they didn't even fix it, they only told me what was wrong and said they didn't wanna fix it.
So droppd carbs off to red baron(big ups to these guys)
they said no problem.
hopefully picking them up sometime this week.

Lame thing is they told me even when they replace the valves and adjust them to hondas specs the bike still might not go if the needles holes have wear. and ill have to source some 2nd hand vfr400 carbs.

so lets just hope i havn't wasted close to $500 getting these shitty carbs going haha.

VF AAR
9th October 2007, 08:23
Are they in the middle of the V? If so they could be joined on a pivot type arrangement that needs loosening off. Down load a manual if you can.


Yup middle of v, i just pried them off with a powerbar and they poppod out.
just had to loosin the hose clamps riiiight off