RVF400 trouble, possibly worse.

[CammyGTIR]

Taken from my old bike forum...

Just yesterday, on my way home from work, enjoying the lovely orchestra of both a V4 and a Tyga maggot working in unison....my bike broke down

What has me worried is that its exhibiting the same signs as when I blew the engine in my Cibby.

It started to splutter, lost power and generally sounded as if I just started running on three cylinders. I pulled over in quick order, fearing the worst.

I let it settle for a few minutes and then started it again, which it did with no problem. However, just a few hundred metres down the road, same problem. It was at this point I decided to play it safe more so than sorry.

The first thing I am going to check are the sparks. If I've melted the crown again...

What else does it sound like I should check?

Cam

[superlite]

Could be a few things, but doesn't sound terminal to me.

Have you checked the vacuum hose from the fuel tap to intake manifold? They tend to perish and cause intermittent fuelling problems (particularly at higher speeds/revs). Could also be reg/rect related, but if it was that bad, chances are you would have had a flat battery by now.

[Neosophist]

I'm with you on this one.

Sounds like its running out of fuel.

This is usually either.. (in the following order)

1.) Vaccum pipe split / deteriorated.

These engines use a vaccumn from the engine to open the fuel tap (even when its set to on, no fuel will flow unless the engines turning over) If the vaccum pipe packs up the tap closes and the bike runs out of fuel.. old pipes can collapse in on themselves at high rpm and stop the fuel flow.

2.) Blocked tank breather.

The breathers on the top right of the tank.. when it dies open the fuel cap.. if you hear a rush of air the vent / breather is blocked up.. this causes a vapour lock in the tank and no fuel will flow into the carbs.

3.) Blocked up tank filter.

Theres an inbuilt mesh filter on the tank (if its the same as the 24.. somone correct me if i'm wrogn here..) but if this is blocked you wont be getting full fuel delivery.

My moneys on the vaccum pipe.. it's a small pipe that runs from the tap to the cylinder head.

[CammyGTIR]

Thanks for the good replies guys, I will definitely check the hoses out.

2. Blocked tank breather.

The breathers on the top right of the tank.. when it dies open the fuel cap.. if you hear a rush of air the vent / breather is blocked up.. this causes a vapour lock in the tank and no fuel will flow into the carbs.

I have a Tyga tank so there is no hose like other ones , this has been bugging me for a while now, so am I missing parts or something? I'm not even sure if I have the breather anymore so do you have a picture or anything?

[Malc]

I'd be checking the sparks, paying attention to the leads/caps to make sure there is no HT lead breaking down under load.

[Drunkn Munky]

RVF dont have a breather on the top right of the tank, its underneth. You should have 2 pipes coming from the bottom of the tank, 1 breather and 1 overflow i belive. You say you have a TYGA tank, do you have the carbon one then?

Sounds like the vacume pipe to me tho or dodgy electrics.

[micpec]

A Tyga tank? Never heard of it. But I may have received one of these last week, it was painted all black and just had a hugh Tyga sticker on it.. Just joking.

with what Drunkn Munky notes...the breathers are from underneath the tank, not on top as the NC30 tanks. May well be an failure in the fuel tap assembly. Test it with apply some vacuum on the vacuum hose that is fitted on the fuel tap. Check if fuel is coming out of the fuel line.

[CammyGTIR]

I'll clarify what I mean by Tyga tank...

http://tyga-performance.com/site/produc ... ts_id=1533

Its got that thing. So where do the breather hoses go?? Will it mean my bike runs like shit if I don't have them?

[leef82]

sounds simular to a problem ihad on my nc30, but when it started agen i was sticking the choke on to stop it spluttering, all it was in the end was dirty carbs.

[Drunkn Munky]

Ok that tyga part is called a tank apron, those 2 holes have nothing to do with breather pipes. You should have 2 plastic air ducts that attach to them and the holes in your front fairing, don't panic If you haven't as they are of no use at all apart from looking good.

Lift your tank up and underneth on the left side (I think) should be 2 rubber pipes about 5-10mm diameter, these are your breather and overflow pipes, while your there check the vacume pipe on the underside of the tank on the right, it's a small pipe that attaches to fuel tap and disapears into the engine area. This pipe must be in good condition with no kinks or splits what so ever, if it looks suspect in any way replace it.