anyone got a spare fuel pump?

**erik** · 4th December 2005, 14:04

Update:

Made a container thing and hooked the fuel pump and a pressure gauge to it. The pump pumped fuel into the container and cut out at about 2 - 2.5psi, which is what Motu said it should be.
So I'm now thinking the pump is ok.

My attention turned back to the cam chain. It had been quite noisey earlier in the year and the cam chain tensioner spring wasn't pushing it any tighter. So since the cam chain tensioner still had a lot of available travel (lots of teeth left on the ratchet thing) I manually pushed it in another click and the noise died away.
Anyway, I checked the cam timing, lining the dots on the cam shafts up with the locating marks on the cam caps and measured how many degrees (4.5°) past TDC the crankshaft had rotated.
So now I'm hoping the poor running is due to a stretched cam chain and late valve timing. Dunno if 4.5° is enough to make a difference, but the cam chain should probably be done anyway, so I reckon it's worth a go.

**DEATH_INC.** · 4th December 2005, 17:25

No,4.5deg won't do it ,you can go a lot further than this and it'll still run fine,just be gutless.
What've you tried so far? It sounds like a weak spark or a carb problem to me.
BTW if you wanna try a pump bring it over and I've got a fzr1000 pump on another bike we can raid to try if you want.

**erik** · 4th December 2005, 18:52

Originally Posted by DEATH_INC.

No,4.5deg won't do it ,you can go a lot further than this and it'll still run fine,just be gutless.
What've you tried so far? It sounds like a weak spark or a carb problem to me.
BTW if you wanna try a pump bring it over and I've got a fzr1000 pump on another bike we can raid to try if you want.

Darn, I was hoping it might be the chain...

So far I've tried:

Changing the plugs - no effect.
I've measured the coil's resistance, found that there was a bit of corrosion in one of the plug caps which increased the resistance heaps, so I cleaned that and the resistance returned to normal. - no effect.
I've checked the fuel pump pressure like I described above - seemed ok.

Doesn't seem like I've tried much.

I might take you up on that offer as soon as I've got the new cam chain and exhaust shims in.

**DEATH_INC.** · 6th December 2005, 19:03

While you got it apart clean the carbs thoroughly,pull all the jets and clean out under them etc....just clean them all spotless.

**Mattyc** · 6th December 2005, 19:48

The fuel pump should have heaps of flow for that bike.. 2.5psi should be sweet
may sound silly but have you compression tested the engine

check your needles and seats, check that all float levels are set the same, they may be non adjustable, but it may have a bendable brass tab or arms they need to be near identical, and have to let the bowl fill fully. Check the float itself, if its brass it could have a leak, ive only ever seen one, the plastic floats ive never heard of one fucking out . air compressor is your friend here blow the carb out , jets etc dry it all out and make sure the float bowls all seal.

once back together id have the carbs balanced, if you dont have the little flow tool or dont want to pay someone, a farm type way is wind all the air screw right in, counting the turns, comparing each one generally you can get an idea as to what it should be, turn each screw out the same amount and use that for a starting point. thats pretty simple shit you may have already done

**erik** · 6th December 2005, 22:11

Aww man, I was hoping to avoid pulling the carbs apart. I've had them apart and cleaned them just under 2 years ago and it's not my favourite job

I've compression tested the engine, it got pretty much exactly 100psi on all cylinders (with the engine hot after running it for a bit). I realise this is kinda low, but last time I checked the compression (with engine cold) I got values ranging from 82psi to 94psi (before I did the valve shims) so I don't think the compression has changed for the worse (unless there should be a larger difference between hot and cold).

I'll check the float levels before I pull the carbs apart. Haven't done it before, but I read you can connect a small piece of clear tube to the float bowl draining tube and see where the level comes up to (I guess let the pump prime the carbs then turn it off before connecting the tubes...). The floats are plastic.
I've got a set of carb vacuum gauges, last time I checked the carbs were balanced ok.

**Motu** · 7th December 2005, 06:58

I'm impressed with the length you go to in making your little tests Erik - most people just put a new pump on then say ''that didn't fix it''.But you need to test flow as well - flow and pressure are related,but to have one doesn't mean you have the other.Ultimatly you need to test it can flow the required amount at the pressure you need,sometimes it can make the pressure but not maintain flow.Try and make the pump fail by moving it around,checking for faulty wiring etc.Most pumps fail on startup,that's when the biggest load is applied...make sure it starts everytime.

**Mattyc** · 7th December 2005, 07:19

Originally Posted by Motu

I'm impressed with the length you go to in making your little tests Erik - most people just put a new pump on then say ''that didn't fix it''

Yes kudos to you EriK you dont give up easilly

The Flow test Motu talks of it not at all a silly idea at all.

another thing, which you have probably already checked - there are no cracks in the rubber where the carbs clamp on to be causing a vaccum leak

**DEATH_INC.** · 7th December 2005, 20:00

A little trick I learnt to balance the carbs is to use a small dril bit(the blank end...),wind the idle screw open and use it like a feeler gauge,start on the carb with the idle screw then adjust the others to the same.Not the perfect way but not too far off either.

**erik** · 10th December 2005, 20:55

Thanks Motu and Mattyc.

Thanks Death for the pump, you're right, it's not the pump...

So I've started begrudgingly pulling the carbs apart. The main reason I dislike pulling carbs apart is all the cleaning you have to do with kerosene. Hopefully all the seals will reseal when I put them back together. Carb seals are bloody expensive.

So far I've cleaned them and pulled one carb apart.
I noticed when cleaning them and emptying the float bowls that the first bit of fuel that came out was darker coloured and also there were little bits of stuff that looked a bit like jelly. I think the darker stuff and gelatinous stuff might've been partly water judging from how it felt and since it didn't catch fire when I tried setting it alight...
There was a fair bit of sediment in the float bowl that I pulled apart, have only looked in one so far. I don't kniow what the stuff is or how it got there. I recently replaced the fuel filter (like a few months ago). My dad reckons it might be stuff that got in through the float bowl air vents?

Anyway, I'll work more on it tomorrow. Time to have beer and relax now.

**Sketchy_Racer** · 10th December 2005, 23:19

well,,me personnaly, that looks to be the prob.

There shouldnt be any crap at all in the carbs, so..... get the air compresor and blow out the whole carb. Then what i do is get some fuse wire in the suitable thickness then run it up and down the jets a couple of times to get any junk out, then blow it out with air, repeat. The fuse wire is hard enough to get any crap out but soft enough to not scratch the jets.

Cheers, Glenn

**FlyingDutchMan** · 11th December 2005, 10:14

Looks like it could be rust from the petrol tank. I had a really rusty tank and it caused all sorts of problems including hydrolock. I fixed a couple of weeks ago (lots of hydrocholoric acid and a POR-15 kit) and its been running much better since. Rust seems to have the ability of getting through everything including paper fuel filters.

**FROSTY:Me** · 11th December 2005, 10:24

Eric--Mate stuff the Kero --Take ya carb set round my place and use my air gun to blow the carbs out.
Once theyre clean as a whistle -id fit an inline filter AND -drain your tank and give it a bit of a wash out--I'd suggest the water is out of ya tank so cleaning ya carbs will only be a temp fix if ya dont clean ya tank out

**erik** · 11th December 2005, 15:30

Originally Posted by FROSTY

Eric--Mate stuff the Kero --Take ya carb set round my place and use my air gun to blow the carbs out.
Once theyre clean as a whistle -id fit an inline filter AND -drain your tank and give it a bit of a wash out--I'd suggest the water is out of ya tank so cleaning ya carbs will only be a temp fix if ya dont clean ya tank out

Thanks for the offer, Frosty. I actually switched to using engine degreaser, rinsing the parts in a bucket of water and then drying them with an airgun (I bought a small compressor not long ago - bloody useful

). They're all done now, I just want to check the float levels then put them back in the bike.

I had a look in the tank and there's crap in there. It looks like dirty water. I looked in there before and thought it looked a bit funny, but didn't realise it was water in there

.

I'm hoping the tank hasn't started to rust and I'll just have to clean it out.
It's a bit annoying about the filter, I put a new one (genuine yamaha even) in a few months ago. I'll just get an aftermarket filter next.

(In the photo looking into the tank, the bottom of the tank is on an angle and the line between the dark stuff and clear steel is the edge of the cruddy water.)