Maiden voyage problems.

[LewisB]

Hey guys, I’m wondering if anyone could help me to come up with a plan to investigate some issues I have with my vtr.
I should start by saying, I purchased my vtr 2 weeks ago from a dealer about 150 miles away, without seeing it first! And had it delivered. After taking delivery from a third party delivery company, I started the bike up and it had a very rough idle. It didn’t want to stay running without the choke until it was hot. I then fitted manual cct’s, and after I checked valve timing and clearances. (All within spec, although cams where slightly off but not enough to warrant moving a tooth). After putting everything back I notice the front carb had an open T pipe coming off for balancing (it is in the service manual that carbs were overhauled last year) so I blanked that off, but the rear carb had its screw put back in. After putting it back together the bike did idle slightly better, and didn’t stall at idle.
Today I took her out for her maiden voyage (what an awesome bike!) but here’s the problems I’m experiencing;
* had to keep the choke on for about 2 minutes
* Idle is rough, it bounces between 1200-1500 rpm
* While riding Under 2500 rpm there sounds like a misfire and clanking noise when it misses, making it jerky
* Deceleration is very poppy and gurgly
* Stoping at traffic lights it stalled a couple times so I had to keep it revved ever so slightly
* I also noticed the bike got up to 105 degrees but the fan didn’t kick in

I don’t know if this one is the nature of the vtwin but it vibrates alot! coming from in-line 4’s it was abit of a shock, although I’m sure the mrs will love it!

Apart from that I’m absolutely in love with the bike, it feels so much lighter than my previous ‘02 zx9r, and felt just as nimble as my old zxr400!

I’m sorry this is so long but I’m hoping you lovely people will share a little wisdom and help me come up with a plan of action to get her running smoothly.

Thank you, Lewis.



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[tony.mon]

You shouldn't need to keep the choke on once you've pulled away, and you can't ride one of these at low revs, keep it above 3k when riding and all should be well. They don't like chugging.
The lumpy tickover is indicative of a carb problem, check how far the mixture screws are screwed out from fully in.
Around 1.75 to 2.5 turns is about right, but check in the workshop knowledge base to find some baseline settings.
Other opinions will be along shortly!

[sirch345]

I'm not sure how many miles this bike has done, or if it has been standing for any length of time before you got it?

Just to add to what Tony has suggested, I would check the carbs to see if they need balancing. Take a look at this link: http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=18430

Also check all the vacuum hoses for splits etc as one of them could be drawing in air.
Then there's spark plugs, and or air filter for the easier possibilities

The cams being less than one tooth off is fine

Chris.

[LewisB]

I'm not sure how many miles this bike has done, or if it has been standing for any length of time before you got it?

Just to add to what Tony has suggested, I would check the carbs to see if they need balancing. Take a look at this link: http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=18430

Also check all the vacuum hoses for splits etc as one of them could be drawing in air.
Then there's spark plugs, and or air filter for the easier possibilities

The cams being less than one tooth off is fine

Chris.

Thanks Chris! The mileage is just shy of 50k and has done 150 miles in the last 6 years, so lots of standing around. I will change the plugs, have a good look at the vac hoses and if that makes no difference I will look more into setting up the carbs!


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[sirch345]

I'm not sure how many miles this bike has done, or if it has been standing for any length of time before you got it?

Just to add to what Tony has suggested, I would check the carbs to see if they need balancing. Take a look at this link: http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=18430

Also check all the vacuum hoses for splits etc as one of them could be drawing in air.
Then there's spark plugs, and or air filter for the easier possibilities

The cams being less than one tooth off is fine

Chris.

Thanks Chris! The mileage is just shy of 50k and has done 150 miles in the last 6 years, so lots of standing around. I will change the plugs, have a good look at the vac hoses and if that makes no difference I will look more into setting up the carbs!


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In that case I expect you will end up having to strip the carbs. If the carbs were not drained while it was standing not being used, petrol will have gummed up the jets,

Chris.

[LewisB]

Thanks Chris! I’ve ordered a set of spark plugs and the kit to balance the carbs and a multimeter to check the tps, if this all fails I will strip the carbs


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[lloydie]

Start with a service and a good carb clean . Check all pipes for vac loss .
You can’t ride the storm like a big il4 they just don’t like it as others have said stay in the correct gear to keep the revs up

[sirch345]

Thanks Chris! I’ve ordered a set of spark plugs and the kit to balance the carbs and a multimeter to check the tps, if this all fails I will strip the carbs


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It's worth trying those things first

When you check the TPS, if you get yourself 2 of those (red size) spade terminal connectors which will slide onto the TPS terminals. With a short length of wire attach the multi-meter probes to them both, that will make the job easier than trying to hold the probes on the appropriate terminals and look at the multi-meter at the same time. We have found setting the TPS around 570 Ohms works the best for road use.

If you do end up stripping the carbs down don't mix up the parts from the front and rear, as not all parts in both carbs are identical,

Chris.

[LewisB]

Thanks Chris! I’ve ordered a set of spark plugs and the kit to balance the carbs and a multimeter to check the tps, if this all fails I will strip the carbs


Sent from my iPhone using Tapatalk

It's worth trying those things first

When you check the TPS, if you get yourself 2 of those (red size) spade terminal connectors which will slide onto the TPS terminals. With a short length of wire attach the multi-meter probes to them both, that will make the job easier than trying to hold the probes on the appropriate terminals and look at the multi-meter at the same time. We have found setting the TPS around 570 ohms works the best for road use.

If you do end up stripping the carbs down don't mix up the parts from the front and rear, as not all parts in both carbs are identical,

Chris.

Thanks for the tips buddy!

[LewisB]

I’m glad to say the bike it running amazingly now! 95% of the popping on decel is gone, 99% of the clunking is gone (it made 1 clunk noise on an hour ride) idles great now, and low rpm riding is actually pleasant! Thank you everyone for your tips and support, couldn’t have done it without you! Here’s a list of everything I did to fix the issues;

Cleaned carbs
Played with mixture screws
Balanced carbs
Set tps
Replaced carb boots
Replaced air filter and spark plugs
Blanked off the previously open balancing points.

I’ll copy this post into another thread I had which talked about some of these problems.

[LewisB]

Unfortunate I’m still having some running problems, although it is running a lot better than it was when I bought her!

My problems now are;

Choke doesn’t seem to increase revs much. I’ve set the idle to 1200rmp when hot, when it’s cold it runs at 1500 with choke but will stall if the choke isn’t on until it hits 60 degrees.

Idle is still a little erratic and on rare occasions one cylinder misses

Very jerky at bang on 2500rpm - I figured out on todays ride that it goes down to 1 cylinder at this specific rev point. It does kick in and out but it spend about 5 seconded on one cylinder before it started jerking (the missing cylinder firing sometimes but not constantly)

I did wonder why the exhaust always smelt of fuel at idle and low revs in neutral and now I realise why! I can’t see it being mechanical as I’ve done the valve clearances, checked timing, replaced spark plugs and air filter so I’m now going to trawl the forum looking for suggestions and make a list of electrical components to test, but my go to thought is plug caps and htc leads.

Any suggestions are very welcome and I will update when I start testing things

[tony.mon]

Choke doesn't lift revs much, sounds normal from what you've described.
Plug or coil or plug cap seems the likely cause. Can you work out which cylinder it is that misfires?
Oh, and occasional misfire on tickover is normal, it may even cut the engine when cold if you don't warm it up a bit before pulling away, first corner stalls are the usual result.

[LewisB]

Choke doesn't lift revs much, sounds normal from what you've described.
Plug or coil or plug cap seems the likely cause. Can you work out which cylinder it is that misfires?
Oh, and occasional misfire on tickover is normal, it may even cut the engine when cold if you don't warm it up a bit before pulling away, first corner stalls are the usual result.

Thanks for your input tony!
Ah so my other little problems aren’t really problems with just my bike! That saves me a lot of work haha. What I can try to do is get it to the point it’s missing then pull the front plug cap and see what happenes! Yes so I always get her to 60 degrees before taking off so I’ve not had an issue with it stalling while riding cold.

[Duffy1964]

You could try the stick coil modification for improved spark. There is a write up on here somewhere. Also on the front cylinder there is a small drain hole at the Bolton of the spark plug that sometimes gets blocked which can cause the front cylinder to cut out in wet conditions.


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[tony.mon]

You could try the stick coil modification for improved spark. There is a write up on here somewhere. Also on the front cylinder there is a small drain hole at the Bolton of the spark plug that sometimes gets blocked which can cause the front cylinder to cut out in wet conditions.


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Good point. The drain hole exits facing forward on the front cylinder, below at to the rh side of the exhaust. A wd40 straw fits perfectly.