Re: Hero Impulse ownership experience

Before I bought mine second hand, in Feb 2016, I enquired in many Hero showrooms, not just in the MMR region, but all of Maharashtra too, about getting a new one. Though none are available around Mumbai.
To my surprise, a few dealers do have the bike in stock! also, they were willing to give a discount.
But I had to transport the bike from Yavatmal/Beed district to Mumbai myself and also register it in the Mumbai RTO myself, so dropped the idea.
If you are interested, I can give you the contact details of these dealers...

PS: about the Himalayan, opinions divided, don't want to go OT, but it has carried on the RE legacy of niggles/issues that you wouldn't expect from a modern 2016 bike. I have been through the ownership review of it, and from what I read, it killed off whatever excitement I had for it.

Hero Impulse ownership experience

Okay. Thanks.

Which year model is your bike? And yes please do give me the dealers number. Are you happy with the 2nd hand hero impulse? What price did you buy?

Re: Hero Impulse ownership experience

Mine is a July 2012 model.
Will PM you his details.
Coming to the latter part of your question:
I have had the fortune of riding the bike in the dry and also now, in Mumbai's famous monsoon. Just like any Hero bike (with a Honda engine) its pretty much a head ache free ride. Maintenance costs are next to nothing and spares are reasonably cheap (if you can find them ), heck, even the chain doesn't demand regular tightening/lubing, like my KTM. The riding position is extremely forgiving, you sit pretty upright. I have gone for a 700 km ride on NH 17 apart from the usual daily commute. Done a fair bit of off roading in the ghats. The bike can take pretty much what you throw at it. It even corners pretty well (if you don't ride it like a KTM), but it struggles on the highway, top speeds and quick over takes are not its cup of tea, but since the engine's not been tuned for that, its something you've got to live with.

Re: Hero Impulse ownership experience

I tried all over the places

My friend owns a Hero Showroom , Tried to get a Brand new , But No stock and No production

hence bought an pre-owned impulse and restoring

Finding too much difficulty in finding the spares

spend 48k on the bike

3k on insurance and transfer now spending another 10k on spares like Disc rotor and Disc setup and sprocket and coneset and excluding set of tyres

I loved the bike hence am spending this much

the bike engine is very good hence am restoring the bike

thinking this post will be useful for u

Re: Hero Impulse ownership experience

It's not quite that simple... it took me awhile to understand this myself: The way a carburetor works is that by using a venturi (reduced diameter section in the airflow), a low-pressure area (vacuum) is created in that reduced diameter area... which by design is the same spot where the needle / needle jet are and the fuel is therefore sucked in to the airstream for mixing / atomization.

Now the thing is that the amount of vacuum created depends on the velocity of the air and on the diameter of the venturi. Given an identical sized engine displacement, velocity will be higher with a smaller venturi, and thus vacuum (suction force) will be more; likewise, given an identical sized venturi, a larger displacement engine will pull more air, hence create higher air velocity through the carb; And so in either case, more fuel will be pulled through an orifice (jet) of a given size when velocity is greater, and less fuel will be pulled through it when velocity is less.

The Impulse carb at 28mm venturi is rather oversized for a 150cc engine (foreign-market trail bikes using this same engine [CRF150F] have only a 24 or 26mm); correspondingly once the slide is fully up at WOT, the maximum velocity is less than it would be on a smaller carb, thus vacuum is less, and amount of fuel drawn through the 132 jet is also less than it would be than if, say, you had that same 28mm carb mated to a 500cc RE. Which is why the Karizma, and even 500cc RE's, incidentally, use a jet smaller than 132 without running terrible lean. Big-displacement RE's suck more fuel through a smaller jet due to the higher vacuum created in the venturi.

That said, the Impulse runs richer than other bikes at altitude, and as Aniket noted, I also experienced problems starting at 8,000ft or even a little less. My feeling is that vs. other commuter 100-150cc bikes, it probably has a different (longer-duration) camshaft fitted to give a little more midrange/high-end bhp than, say, an Achiever with basically the same engine. Trouble with longer-duration cams is that at anything less than very high rpms, compression ratio effectively decreases, as cylinder pressures decrease, unless combustion chamber volume is also decreased (which does not seem to have been done on the Impulse, as the specs still state a 9:1CR). And low cylinder pressures create big problems at high altitude, because the lower atmospheric pressures "up there" cause an additional decrease in effective cylinder pressures. So incomplete combustion and the associated misfiring are common. A local bike tour operator mentioned this to me as the reason that RE AVL Machismo 500's run much better than the UCE 500's at high altitude. I haven't checked the specs, but it sounds plausible.

One of these days I'm either going to mill the stock cylinder head (to reduce chamber volume), or put a big-bore piston/cylinder kit on there (increase cylinder volume), either of which would raise the compression ratio / cylinder pressures and probably make the bike run a lot better on the high passes.

Beyond the main jet size (which mainly affects full-throttle performance), it is possible as I outlined in my team-bhp thread (search for "KB RTZ Impulse") to lower the needle in the slide. This reduces fuel flow in the midrange / half-throttle range, and is overall much, much more effective than merely changing the main jet. Also won't negatively effect top speed as much when you get down lower again, and you can gain kmpl in normal riding at lower altitudes as well.

About to head to Leh and/or Spiti in the next few weeks. I had a home-made free-flow foam air filter already, and after lowering the needle maybe 1.5mm's and putting in a smaller main jet (can't remember what size finally, maybe a #120), the bike was running really well as high as 14,000+ft. Except that the slide was constantly (famously) getting stuck. I bought a Unicorn slide but haven't put it in yet, having worked out another jugaad fix in the meanwhile (think that's in the thread, too): Basically trimmed off the rubber tab on the diaphragm and put the slide in 180 degrees backwards! A bit of off-idle leanness now till fully warmed up (probably partly the tuning, as I've not re-tuned after last year's Spiti run for the lower Manali altitude), but otherwise good driveability and much better FE than earlier. Been running nearly a year now under all sorts of conditions without sticking, so I'm quite happy.

-Eric

Re: Hero Impulse ownership experience

Having read a lot about the carb and the issues/problems associated with it, in a recent service I opened up the carb with the aid of a mechanic. Disassembled the bad boy and used liberals amounts of carb cleaner on it. Although I am at sea level here in Mumbai, the state of the carb rubber wasn't so great: the black rubber part as become a greyish/silver colour. I contemplated changing it with a Honda one, costs around 630/-. As per the mechanic, it can go on for longer, but I wonder if its time for a change.

Re: Hero Impulse ownership experience

Hey [MENTION=72938]ringoism[/MENTION] your are back ! Glad to see you explaining, less of what I do though penning down in a plain manner the wholesome idea (approx) Layman-ish-ly !

Anyways here's another aspect of why the stock Impulse gave low kmpl figures than the other Impulse with Zma's mill was 1000rpm difference (low rpms being on the Impulse with zma's mill) hence less busy amd less power strokes and thus less A/F consumption as compared to impulse on stock mill ! Thats when Impulse is on 132 main jet size !

Difference in Rpms still had to be the same on 126 jetsize too (that of zma's on stock Impulse) but the kmpl figures increased slightly for stock impulse but still low than that on other Impulse with zma's mill ! Thus justifying my statement of low jetsizes in turn churning out "comparatively" high kmpl figures ! and also justifying the pressure difference and the vacuum created at the venturi which acts as a big deciding factor for fuel consumption !


Nice old school stuff facing the head getting bump in CR ! Anyways ... as per the slide i almost rounded off the two triangular depressions at the slide bottom and guess what i rotated the slide too, not 180degrees but a tad enough to let those two triangular depressions not glaze the bore it runs in and remains free comparatively at least and doesn't gets jammed in as it usually does (mostly at closed throttle coasting). Been 4-5000kms now no slide problems now.

...other than the slide needle breaking and getting sucked in ! Twice it has happened till now. A friend Philip Ivor witnessing the same thing thrice (now moved to other carbs though) so will i maybe ! Maybe a Zma mill swap !

Re: Hero Impulse ownership experience

^^^^
Anyone with a suggestion?? Ankitville..ringoism...senior pros....?

Re: Hero Impulse ownership experience

Is there any other problem other than the colour fading ? What caused you to open the carb? ..and how much on the ODO?

Re: Hero Impulse ownership experience

I have a previously used model, with about 22k on the odo.
The reason to open it up was I didn't trust the previous owner to have ever cleaned it and also with dodgy fuel supply I had even more reason to do so.
Anyway, apart from the discoloured rubber and a slightly worn out needle, there's nothing much. It was pretty clean not much gunk built up.
As I mentioned in my earlier post, the bike's been run at sea level mostly.

Re: Hero Impulse ownership experience

Slightly worn out needle or the slide? Maybe the slide !
That's very characteristic of Vacuum CV carb. Scoring marks on the slide (not needle) are inevitable ...and further will lead to the slide jamming (as it did with my Impulse and several others here too). Anyways back to your question and your mechanic's suggestion yah for the while you can run on the same slide. Wait for till it more scoring and then you can go for a new one if you wish to ! I didn't still though with 35k on the ODO sorting, brushing, rotating, polishing the stock slide but I'd, if have to, will go again for the stock slide 535rs !
and maybe another carb is what i have in my mind ! Wire actuated slide ones !

Re: Hero Impulse ownership experience

Hi everyone just want to know has anyone used k,n air filter if so how are the performance and wt are the issues you are facing, also i want to know how to change the stock sound without ruining anything, thanks in advance

Re: Hero Impulse ownership experience


Right the slide, my bad.
It is a little worn out, though I consciously avoid too much engine braking to off put the inevitable jamming.
For now, just rubbed the slide with sand paper, though the wearing on it is quite prominent.
All the sucking in and out will definitely warrant a change on a CV carb, do +1 on the wire slide carb, do keep us posted if you decide to take the plunge!

Re: Hero Impulse ownership experience

Guys....sharing few pics of my bike....I am just enjoying it.....
BTW upgraded to Himaliyan.....but still keeping the Impulse......

Re: Hero Impulse ownership experience

[QUOTE=animesh2304;1246012]Guys....sharing few pics of my bike....I am just enjoying it.....
BTW upgraded to Himaliyan.....but still keeping the Impulse......

You are rich!