So ive bought a RVF 400 a few months ago and loving it and hating it haha.
After months of searching and being from port macquarie that meant 2 trips to sydney 400- 600k's each way and getting nowhere on both of them for reasons such as telling the owner i was coming on this saturday for the past fortnight and him selling it the thursday 2 days before i leave,
looking at another one that had a broken windshield, horn blinkers and brakelight not working the brake master cylinder was broken battery would always run flat he told me and not to mention the rough look of the fairings and an exhuast that wasnt held on by anything that he told me you had to keep an eye out that it was still on when riding plus the frame was covered in salt marks when he was at around 50 k's away from the beach
and then the 3rd bike i was going to look at i was roughly 10 mins from his home and 6 hours from mine said im going out and wont be back till late tomorrow and said come back then (not an option) so he missed out on a sale.
All that was just one of the trips aswell haha so things werent looking to good.

So a few months later after dreaming about owning one everyday, one appears in broken hill for only $5500 anyone in australia would realise thats bloody cheap for here ecspeccially with a full tyga kit and 24000kms on the clock, a mere 1600kms away and 2 days non stop driving later, im there looking at it. (conviniently i was going on a 4wd and dirtbike trip through flinders ranges simpson desert area and broken hill was the starting point haha) So after half an hour or so going over it and getting my dad to test ride it and not finding anything funny happenning the deposit is given. The next 2 and a half weeks were some of the best times ever but i couldnt wait to get back home with my new bike!!



I cant seem to make the images any bigger no matter what i do?

So ive made it home and taken it straight to the mechanic because it was bogging really badly between 4000 and 6000 rpm so i decided to give it a FULL service here is the list







And the resulting dyno test 53.3bhp at 12500rpm with max being 55.5 bhp at 14300rpm and torque peaking a 21.8ft/lb Bikes engine is completelly stock i was told by mechanic who had previous experience with these bike when he was living in sydney Luckily




So since then ive know i was going to have to rejet it and tune it up to get some more power and remove the flat spot but i was going to wait till i had the money for a full tyga system and do it all at once along with a tyga lower triple clamp if compatiable with a stock upper triple clamp if not get both tyga because the front end was a bit twisted but luckily the forks werent bent.

So its been a few months since then and i finnaly got some money to spare as i had paid of the debt to mum and dad had lent me to get this bike and i realise is leaking a bit of coolant but wrote it off as nothing till the bike started to heat up. When that started to happen i have taken the fairings off to trry and find the leak.

Radiators fine, good i thought didnt want to spend money on new ones, but then there is no leaking from the hoses or the overflow bottle under the seat, where it looked like the leak was coming from. so i realised that something is up and i take it to the mechanic and he puts it down to the radiator cap realesing pressure to early, so they have put new one on and what do you know, its still leaking so that leaves one thing, head gasket is damaged (why couldnt the radiator have been leaking haha) so now im looking at at least another 1500 to get it fixed

So i figured while the engine is all apart i might aswell get it rejetted and tuned up properly and since the shock and everything will be removed dad has suggested i remove the swing arm and check all the linkage.

So what i am hoping for now is for some advice on what the best jet sizes to use would be to get some extra power out of the stock engine and if there is anything else i should consider doing while the engine is apart. Eventually i would like to get it resprayed to look something like these but havent decided on colours yet as its not at top of my list now haha




Thanks for reading any advice would be appreciated

Drew

I think you need to investigate further before assuming a head gasket's gone. Blown HG's are quite rare on these bikes (but not unheard of).

Where does it look like it's leaking coolant from? Big difference between a head gasket and the rad cap?

nmdrew wrote:So what i am hoping for now is for some advice on what the best jet sizes to use would be to get some extra power out of the stock engine and if there is anything else i should consider doing while the engine is apart.

Rejetting won't make any more power if the bike is standard (can't tell in pics). The best thing to do is remove the carbs, pull them apart one at a time and write down on a diagram what sized jets, pilot jets, emulsion tubes and needles are in each carb. Then give each carb and carb part a good clean - make sure no jets are blocked etc.

It sounds like it was a good deal, I'm sure you'll get it sorted.

Pic size is something to do with the settings on your host (postimg).

Thanks but its been a few days and they have done all the tests and im only going of what they have told me but they said that after replacing the radiator cap they tested it and said that the coolant was still boiling/bubbling so they have gone and checked the gaskets and said that it is them

The leak looks like it hits the in the very centre of the bottom fairing and around 3 quaters of the way up towards the nose
roughly

Then give each carb and carb part a good clean - make sure no jets are blocked etc.

That was all done in the service i got when i first got it,They just couldnt get it tuned up properly without spending more time on it and for the money id already spent i was happy having it running, even if it was a little off. I don't know the jet sizes or anything like that though, ill be sure to ask them next time i see them.

ill keep trying to get my images sorted

Thanks

Save yourself a lot of money and diy. Remove the fairing and go looking for the leak, unlikely to be a head gasket if water is running out onto the ground.

There is no water leaking onto the ground, it's coolant leaking into the bottom fairings. I did take off the fairings and have a look but I couldn't find where the leak was coming from so I took it to the mechanic. As far as fixing it myself at a quick count there is 9 other motorbikes a work trailer shit load of old surfboards and 2 pushbikes in our garage, not including my bike haha so there isn't slot of spare room haha,

As Magg said, I think you need to investigate further. What sort of car does your mechanic drive?

If it was a head gasket it would cost less than $100 in parts if you did the work yourself.

Hope you have lots of money if you are going to pay someone to work on your NC35, they are labour intensive simply because of the compact nature of the design. There are a number of external water passages located in the V between the cylinder pairs, the thermostat housing and the water pump are other potential leak points.

Where do you live.

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So i finally got my images sorted haha here is the list that is readable of the service it got just a few months ago and the dyno chart

haha well one drives a cbr 1000rr and another drives an 05 r6 haha

I have seen them today and they were aware of the water passages. The thermostat and water pump could explain the leak and why the engine over heated when the coolant leaked out, but would that explain why it was still boiling after they replaced the radiator cap and it was full?

Luckily they overestimated the work involved and the guesstimate of 1500 for the head gasket only and have since quoted between 1000 and 1500 for the head gasket and the full tune up on the dyno to get it running good as it can

As you can imagine if you read the list of things they did on the last service i personally find it hard to believe they would have missed any of the things that have been mentioned so far IF they were fualty at the time of the service(maybe im being naive haha or saying what i want to hear haha) but having said that IF the head has blown in the time between then and now it very well could be any of them so ill pass on this info and anymore i get

Tanks for the help so far

p.s. im in Port Macquarie

They did all that and it still runs like crap and leaks water, you have been had. They flushed and refilled the cooling system and went for test ride yet did not notice the water leak? Replacing the radiator cap seems a strange way to fix a water leak.

I believe the 4000-6000 rpm flat spot is a known RVF issue that can easily be fixed, others on this forum are better qualified to comment as I have a VFR and no flat spots.

Head gasket costs $40 and I expect can be replaced by removing the fuel tank to gain access, again others on this forum are better qualified to advice. For $1500 I would want a new engine and some change, not just a head gasket change.

Unfortunately you are a little too far away for a look see, although if you were prepared to go to Broken Hill to buy it then bringing to the Blue Mountains should be a piece of cake.