Honda Nova: Stalling And Funny Noise After 120 Kph Run

[ClareQuilty]

The other night I had my ancient Honda Nova out for a run - its a great little 20 year old two-stroke bike, a five-speed clutch with dual disk brakes I picked up for 3,500 baht. It seems to have a lot more power than my Honda Tenas (which are newer), as well as a slightly more stable feel.

Anyway, I just had the bike 'tuned' - as in the mixture, idle, etc., set, and between that and a full tank of benzine 95 the bike just seemed even peppier than usual, so I got tempted and drove about 110-120 kph. I'd only ever been up to 100 before on this bike. (it hadn't been running badly at all before the tuning, it was just that the idle was set a bit low)

After I went on down the road another couple of kilometers at a lower speed, the bike suddenly began to cough and die, and I limped along, sometimes restarting it by letting out the clutch at about 20-30, sometimes letting it stop and kickstarting it again. Just before it would die out there was a weird noise for a few seconds from the engine.. almost a growl or rattle. Finally after a brief stop at 7-11 and the grilled-meats stand, it drove the rest of the way home without any dieing or noise, albeit gingerly, at a low speed, and avoiding revving.

I put it away and have yet to take it out again.. I'm wondering what could have caused that. At first it sounded really bad, but then the fact that it was able to go home from the 7-11 (another couple of kilometers) running apparently normally gave me hope that it may not be major moving parts destroyed.

[charlie42]

Sounds like heat seize, the older two strokes were famous for it.

I had a yamaha DT 125 back in the 80s an had this problem when pushing her hard.

when i striped the head and barrel down the was a huge build up of carbon on the exaust port

.

run it on gasohol 91 for a few weeks and give it a blast, will blow all the carbon out

Remember its 20 years old and not designed to be doing 120 km for extended periods

I hope this is of help to you.

[ClareQuilty]

Sounds like heat seize, the older two strokes were famous for it.

I had a yamaha DT 125 back in the 80s an had this problem when pushing her hard.

when i striped the head and barrel down the was a huge build up of carbon on the exaust port

.

run it on gasohol 91 for a few weeks and give it a blast, will blow all the carbon out

That was of great help! Thanks. In fact I have driven it quite a few kilometers since, and it performed flawlessly as it always had, in normal driving (say 60-80). I imagine it has got a big build up like you say - it was owned by some old guy before me who probably never drove over 60 or so.

I've been making quite a fuss about seeking out the real benzine, but maybe there's some use for the gasohol after all?

[charlie42]

I bought a car last september, same thing owned by a little old lady that never drove 60 kmh.it was a toyota lean burn engine so rock solid, i put it on the gasohol and after 400 km was purring like a kitten.

people here are allways complaining about it?.

I run my car and bike on it and never had a problem.

also, if you travel home for months and leave the car sitting the benzine will turn into a jelly.

engine has to be striped for cleaning.not so with gasohol.

charlie

[BSJ]

"but maybe there's some use for the gasohol after all"

As it's a question I will furnish an answer.

Yes, it makes a great fuel for starting the BBQ. Just don't use too much!

[ClareQuilty]

people here are allways complaining about it?.

Yeah it dissolves all your rubber and plastic bits, so your tubes and carburetor, etc. all get ruined, and you get a lot of fuel leaks. Also it tends to make two-stroke lubrication not work very well (breaks down the two-stroke oil).

also, if you travel home for months and leave the car sitting the benzine will turn into a jelly.

engine has to be striped for cleaning.not so with gasohol.

On the other hand gasohol attracts water/moisture, so if you leave it sitting long they say it will have a lot of water in it, and may not start.

Anyway I would never use it long term but if one tank might do some good for a carbon buildup I would consider it. Regardless the bike's obviously basically sound.

[ClareQuilty]

Could this heat-seizure be the result of the bike being tuned to run too 'dry' - as in the mixture is too much air, not enough fuel/lube?

[Beardog]

Could this heat-seizure be the result of the bike being tuned to run too 'dry' - as in the mixture is too much air, not enough fuel/lube?

It is probably the bikes shutdown feature. My 80 yamaha autolube from the late 60's would do this as well when I went over 105 kph. Better it shuts itself down than fry up the rings & barrels!

[charlie42]

Could this heat-seizure be the result of the bike being tuned to run too 'dry' - as in the mixture is too much air, not enough fuel/lube?

maybe not getting enough 2 stroke oil. if she is blowing a lot of white smoke this is not the problem. if not add a little 2 stroke oil to the petrol tank on a fill up.

like the old vespa's.

see how it runs.

[ClareQuilty]

Could this heat-seizure be the result of the bike being tuned to run too 'dry' - as in the mixture is too much air, not enough fuel/lube?

maybe not getting enough 2 stroke oil.

Yeah that's what I meant I think by running too 'dry' - I think the mechanic can adjust the 'mixture' of fuel and air to be either quite 'rich' or quite 'lean', and on two strokes burning lean will mean somewhat inadequate lubrication, and hotter-running, if I understand it correctly. I would think having the mixture adjusted would be enough, rather than adding autolube oil to the gas tank.

[BSJ]

Seriously, if your bike is over 20 years old....don't be relying on the autolube to do the job it did when it was new. Add an eggcup full of oil at every top up just in case the autolube decides to take a holiday.