VTR250 not getting up to speed?

[otter]

Hi all,
First post here :)

So, I have a 1998 Honda VTR250. Done almost 37000KMs.

I've discovered two things,
1) I can get to about 140KM/Hr in 4th gear (correct, about where the red line should be (no tachometer)), then when I change into 5th gear, I lose power and my bike will only hold at about 130KM/Hr, even with the throttle screwed right around. From other VTR250 owners reports I should be getting 155KM/Hr out of it in 5th gear (I'm not very heavy either).
2) If I ride for more than a few minutes with the throttle screwed right around, I also start to lose power and can't hold more than about 110KM/Hr (In 5th), I'm pretty sure I lose power and this happens regardless of the gear I'm in. It's as if my carbs don't fill up as fast as I'm emptying them or something? I can then ease of the throttle for a couple of minutes and the power will come back next time I open it up.

I'm a bit stumped as to what could be causing this (unsure if related).

Any help will be appreciated this much *spreads arms wide*! I've got a ex250 and gt250r to keep up with on the motorways :/

[gammaguy]

fuel.

its not getting enough

[JimO]

you do realise that your going to die in a huge fireball if you go over 100ks

[otter]

fuel.

its not getting enough

Any ideas on getting more?
Any way if I can test if it's a problem before the carb or after the carb?
I guess I'll go nuts with carb cleaner tomorrow when I put more her apart again.


you do realise that your going to die in a huge fireball if you go over 100ks

Don't worry...I'm not in a hurry to do that again...

[ducatilover]

Pull the spark plugs out and check them against this handy page http://www.angelfire.com/fl4/pontiacdude428/Readplugs.html

How clean is the air filter?
Have you had the valve clearances done?
Have the carbs cleaned, balanced and your fuel tap checked.
It's worth replacing the vacuum line to the fuel tap too, if it's damaged you will get restricted flow.
Replace the fuel filter.

[otter]

Pull the spark plugs out and check them against this handy page http://www.angelfire.com/fl4/pontiacdude428/Readplugs.html

How clean is the air filter?
Have you had the valve clearances done?
Have the carbs cleaned, balanced and your fuel tap checked.
It's worth replacing the vacuum line to the fuel tap too, if it's damaged you will get restricted flow.
Replace the fuel filter.

OK, I'll check my plugs tomorrow.
I'm not sure what a dirty air filter looks like, but when I checked last weekend there was still plenty of cleaner looking surface with a few dirty patches.
I checked the balance of the carbs last week with a tube with fluid in it. How would you check the fuel tap?
I'll clean out the carbs and do valve clearances tomorrow. And get me some more tubes and a fuel filter next available day.

[ducatilover]

If in doubt just replace the airfilter, it's not expensive and the bike will love you for it.

With the fuel tap, I used to put the fuel line to the carbs in a bowl/clean bucket and then suck on the vacuum line to see if it was holding vacuum. Mine had destroyed the O-ring in the tap, sadly Honda tells me they only sell the tap and not the seals/o-rings.

[otter]

Awesome, thanks. I'll try that :)

[otter]

OK, last night I:
Checked the fuel tap, when I sucked on the vacuum tube there seemed to be a good constant flow of fuel.
I think I cleaned the carbs out properly, they're a bit more complex that the last carb that I cleaned.
I showed Dad my air filter and he says it looks pretty dirty, so I guess a new one is in order. I'll get the new vacuum tube and fuel filter while I'm at it, Do you have any idea where the fuel filter is though, I didn't see anything on the line.

I'm up to doing the valve clearances, my manual says that I need the special tool "camshaft lifter", do I really need one of them, it also says that I need a special 8x9mm wrench and a valve adjust wrench but I'm not up to actually adjusting them yet?

EDIT: Also, I haven't looked at the plugs yet, but what fuel should I be running my bike on?

[FJRider]

There is usually a filter attached to the fuel tap INSIDE the tank. A lot of shit gathers at the bottom of the tank ... especially older bikes ...

Unscrew the tap off the tank (best to take the tank off first) and flush the tank out. If the inside of the tank is badly corroded ... it may (should) be lined ... It will then stop a few issues with fuel later ..

[ducatilover]

The tools for clearances = 8mm ring end spanner and a flat blade screwdriver and feeler gauges.

I ran the best fuel in my VT250, but, it probably doesn't matter too much.

The filter is where FJrider said.

[FJRider]

Mine had destroyed the O-ring in the tap, sadly Honda tells me they only sell the tap and not the seals/o-rings.

Engineering supply shops sell o-rings of most sizes ... take the old one in to check for size ...

[otter]

Awesome, you guys kick arse...I'll get onto it :)

[ducatilover]

Engineering supply shops sell o-rings of most sizes ... take the old one in to check for size ...

I tried, it's a queer size so they tell me.

[FJRider]

I tried, it's a queer size so they tell me.

Queer size ...mmmm ... and a off a honda ... :innocent:


appropriate wording ... :lol:

[otter]

Well today I was putting my bike back together so that I could take it home, I was about to do valve clearances but after taking just one bolt out of the tappet covers I realised that I'd have to take the radiator off or drop the engine out to get at the front cylinder.
So I gave up, started tightening the bolt back up...way overtightened it and snapped it off...Now I have a bolt stuck in my tappet covers, tried to get a screw extractor from repco and supercheap but they were both much too big, I'll check at some engineering places tomorrow. And I'll have to get a new bolt (Some special thing) too. Fuck...
http://i.imgur.com/asOPR.jpg
Plugs look fine to me
While I'm at it I'll pick up the new fuel filter, air filter and vacuum hose.
Edit: Looking forward to getting back on my bike...it's a good thing I've convinced a good number of friends to get bikes...I've always got spare transport :)

[ducatilover]

Send me a PM with your address and I'll send up a new bolt for you (It may take a week or two, I'm bed ridden currently) I think I have a full set of them in one of my bolt boxes.

I managed to do mine without dropping the radiator. Can't remember how though, I'm sure it wasn't too bad. Mine was a Spada, but there isn't a huge difference in work space.

[otter]

Still not super keen to pull it apart more until I get my '81 SR250 on the road...pretty much the whole reason I got a second bike was so that I could ride one while the other was being worked on and get mad bike mechanic skillz.

I'll try the shops, I'm fine with buying a new bolt (Will try bike busters if boyd or honda don't have them lying around (bike busters apparently wrecks engines after they swap the good engine for someone's broken one)). I'm pretty desperate to get back on the road, but if I can't find one I'll hit you up.

Not a bike related accident I hope? (then again, bike related accidents are usually more worthwhile than slipping in the shower, virus etc).
Got my flatmate's '89 VTR250 tomorrow :)

[ducatilover]

Good luck finding a bolt dude, the ones I have aren't doing anything, no use for them on a ZZR600 :facepalm: I just hoard shit lol

[otter]

Just an update, I've ordered a new air filter for my bike. I got everything back on my bike...although I managed to tip it over in the garage and now have to bend the piece of frame holding my right pillion peg and exhaust back (exhaust hits axle nut)...turns out the CBR600 shocks that I just put on make it just a tiny bit lower. I just got the preload (no c-spanner) changed today, now I just get to play with the rebound and compression adjustments.

I managed to get the bolt out without needing a screw extractor...too bad I just brought one :( Brought a new bolt from the wreckers and I'm all go now. Still not sure if I need to do valve clearances or if I'm now just hearing things because I didn't :(


Boyds gave me an inline fuel filter...then when I went in today and said I couldn't find anywhere for it they said that if I want to replace the built in fuel filter I need a new fuel tap...(why the fuck would I want an inline filter then? meh only a few $)

Hopefully I'll get out sometime tonight to test the top speed now.

[ducatilover]

Yice bit of progress!

You find a rocker cover bolt? :innocent:

[otter]

Yup, 10$ from bike busters. 7$ or something from honda if I wanted to wait 2-3 weeks.
Might need to get myself a new bracket from bike busters too if I can't bend my existing one back :( feels bad when it hits the bolt.

[ducatilover]

That's a bit more than a free one :innocent: Glad you found one though. Good luck with the bracket.

[actungbaby]

Yup, 10$ from bike busters. 7$ or something from honda if I wanted to wait 2-3 weeks.
Might need to get myself a new bracket from bike busters too if I can't bend my existing one back :( feels bad when it hits the bolt.

dude if you need anything esle for you spare motor i got mc 08 engine here vt 250 motor
just got replacment engine as the main bearings shot but need any other parts let me know as just sitting here and going trow out other wise

[otter]

Where abouts is the motor? I'd be kinda keen to get my hands on a motor to pull it apart and see how everything works, especially sometihng so similar to mine (I've read the moterials just have no hands on experiance).

[ducatilover]

Where abouts is the motor? I'd be kinda keen to get my hands on a motor to pull it apart and see how everything works, especially sometihng so similar to mine (I've read the moterials just have no hands on experiance).

Everything in an early VT250 motor or VT250F Magna is the same as yours with the exception of camshafts, porting, headgasket thickness and the gear sets in the gearbox. They work the same, same tappet system etc. Some early examples had a hydraulic clutch too

[actungbaby]

am in palmerston north

mc 08 motor is in bits but have complete mc 15 engine here also




Where abouts is the motor? I'd be kinda keen to get my hands on a motor to pull it apart and see how everything works, especially sometihng so similar to mine (I've read the moterials just have no hands on experiance).