CruxGNZ

Speaking of those "boots", the ones on my bike were super hard from heat cycles and time and this made it VERY difficult to not only remove but also install the carbs back onto the bike. It just plain sucked.
On mine at least, the intake port on the head was sharp enough, and the rubber boot hard enough, that when I install the carbs, the intake port would actually shave little bits of rubber off! I did try several times the other way and install the boots onto the heads, then install the carbs, but the boots were to hard and made doing it this way next to impossible.

Ordered two brand new boots (part numbers are below). I just installed them and WOW, does that make a difference! They just slide on and off super easy now. I even put a little silicone spray inside the boot to aid in slipping it on and off. Now when I remove the carbs, I don't need to remove both clamps on each boot. Just the one on each.

New rubber boots will also seal much better than old, hard boots.



These run about $17 each:
16210-MBB-950 INSULATOR, FR. CARB
16220-MBB-950 INSULATOR, RR. CARB

ssscottyyy

Well I got the carbs off. Might have to order new rubber boots, we'll see. But I did notice a broken plastic bolt where the front idle plunger is secured in place with. Where the heck can I get one of those? Or should I just try gluing it back together since it doesn't need to be in there tight?

Edit: nevermind, I probably shouldn't try gluing it. It'll just break again.

Edit Edit: OOOH! Found something extremely helpful. https://www.superhawkforum.com/forum...etainer-29791/

AndyMX47

Ok - looking for some jetting feedback: 98 Hawk, Dynojet 180f/185r, 48 pilots, DJ springs, no hole drilled in the slides, DJ Needles, stock filter, 2BR slip ons. Had a K&N filter, but....guess what, it stumbled at 3500 rpm. Put a stock filter on - instant tractor-like power.

Bike runs great, wheelies at 3500rpm in 1st if you whack the throttle, pulls nice and smooth from 2k rpm to redline, with good throttle response everywhere. I get about 33 mpg, mix of cruising and merciless flogging in the twisties.

The exhaust is stinky rich smelling, muffler is sooty, and spark plugs are dark and sooty.

Although I could leave well enough alone and enjoy my bike - I feel like it must be able to perform better if not stinking rich.

Should I drop my needles one clip and see what happens, or just shut up and ride my good performing, but smelly rich bike?

Sorry, I'm an engineer and can't stop tinkering until "perfect".

JamieDaugherty

There is your problem. I'll bet you have a bit of low speed surging too. Switch back to #45 pilots and you should see a noticeable improvement.

NZSpokes

Im 40 front and 45 rear. Going to try 35s next week.

AndyMX47

I did wonder a little about the pilots - it does start really easy - with choke, but comes off choke easy in about 20-30 seconds. Sometimes when hot idle will rise to 1400 rpm from 1100 rpm.


No surging while running though, and I do spend a lot of time at small throttle openings when cruising.


I'll order up some 45 pilots and see what its like. Need a @#$@#%& pilot screw tool or thumb screws though.


Thanks for the advice. Don't think I should fiddle with the needles, eh?

RoadManiac

putting shims under the needles richens the mixture your trying to let it run leaner, i think if you dont now anything about setting up a carb get it on a dyno and prepare to spend some $$$$ but at end you wil have a really good running bike

ive been tuning 2 strokes sinds i was 14 but when it came to these buckets
mine still has some fine tuning that needs to be done it was consuming fuel like nothing else, had to much shims under the needle and turned the screws in slightly but i have no idea how lean i can let it run....

NZSpokes

Idle jets are just that, they only effect idle running. They are to small to have any real effect anywhere else.

Im now looking for mains bigger than 200s.

CruxGNZ

PM me if you find some!

NZSpokes

Im gunna buy some drill bits.

thedeatons

What do you think about that Hawk... Think running the 45 pilots would fix the enrichener problem? I have the same issue on my bike, bike won't run when cold unless i babysit it with throttle until engine coolant registers a temperature... Thinking of switching back to 45 pilots to see how cold idling is affect... Thoughts Hawk?

James

batotal

I have the same set-up jetting wise (180 front 185 rear) which is referred to as Dynojet "stage II" and my bike runs perfect with open Yoshimura cans. The Dynojet kit does not recommend 48 pilots and does require the slides to be drilled as well as the stock shims under the needles with the clip in the 4th groove from the top.

I recommend stock 45 pilots and the Dynojet kit installed per the instructions.

NZSpokes

Tomorrow gunna try 210s and 35 idles.

What could go wrong?

CruxGNZ

My gut tells me this will be the sweet spot for the F.I.L. Mod.

NZSpokes

Wow. Yes, yes it does go like hell. But. Tomorrow will try 220s.....

8541Hawk

I will say this thread has become entertaining, if nothing else.

I guess we are all entitled to our opinions and I find it humors to see the same things being said about how I set up carbs and the same silly posts that really have no data behind them.

I see the 48 pilot jets are still causing issues.....

Once again I'll ask the question that never seems to get an answer..... If 48s don't work in this bike, why do they come stock in Euro spec bikes?
Ask the English guys on here, after 2000 their bikes came stock with 48s and there is no line of folks swapping them out.

Of course if you up the mains at the same time you will have issues but that was covered.


Then another "The DJ kit is great"....really got a dyno chart?

So carry on...... this is rather good....

thedeatons

Hawk: can you please give your opinion on the "choke" problem i mentioned in this thread:

https://www.superhawkforum.com/forum...estions-32721/

I just don't know what to do about it, except to think about swapping back to 45 pilots. Any technical input from you would be most helpful. I'm sure i'm missing something, just not sure what... Help?

James

NZSpokes

To be fair my intake is far from stock now. Your setup worked well when it was stock.

AndyMX47

Turns out my memory or eyes were wrong from when I tore the bike apart when I first bought it. After tearing it apart last night, my set up is:

DJ180F, 185R mains
45 pilots, not the 48's I thought were in there
DJ Needles on the 4th clip
DJ slide springs
DJ specified holes drilled in the slides (but not in the needle holders)

So, that to me indicates that most, if not all of my rich condition is associated with needle profile, slide lift, and needle position. I rarely, if ever, run wide open throttle - spend most of my riding time between 3500 and 6000 rpm.

Instead of fighting the DJ needles, I ordered Honda needles and slide springs, will shim them up about 1mm, and have epoxied the extra DJ holes shut in the slides. I will adjust the fuel screws to suit the pilot jets using the idle drop method, and adjust the pilot jet size if my fuel screw settings indicate I should.

Given the hundreds of posts I've read about jetting, unless you modify the engine or use an aftermarket filter, it sounds like these bikes are just a hair lean stock, and its mostly in the needle. Seems like Dynojet overdid the needle profile and lift a little bit. Worst case I might be into the carbs one more time to return the main jets to stock 175F/178R.

I will post between rounds of testing, and let everyone know where I end up. Hopefully finish with a dyno test.

NZSpokes

I find the idle will drop on hot humid days and rise on cold days. But I know Im lean on idles.

AndyMX47

Well, here's where I am now:

175F 178R keihin jets
45 pilots
front fuel screw 2 turns out, rear fuel screw 2 1/2 turns out
stock needles shimmed a total of .050" rear (two brass .025" washers, no stock washer) and .043" front (one brass washer at .025" and one stock washer at .018")
slides with the two stock holes, stock slide springs
2bros slip on pipes, stock air filter

I didn't have time to set the fuel screws with idle drop tonight without risk of terminally pissing off the neighbors.

runs smooth, but there's a lag in throttle response at low rpm - if you whack the throttle open at 3500, I get "ok" acceleration then a burst of power a split second later. Seems like this indicates lean condition to me.

Don't have the "stinky rich" smell like I used to, so I'm heading in the right direction.

Time to tinker with the fuel screws tomorrow - add a turn front and rear and see what happens. Thoughts?

AndyMX47

Well, for after 7 pulls on a dyno at different throttle settings, runs through the gears, and whacking the throttle open at 3,000 rpm - I've got the hawk running like a champ. Some advice, though: don't just copy what someone else did - find a dyno with a/f readings and an operator that knows carbs.

We found that the bike would go lean (a/f as high as 16:1) for a split second when the throttle was nailed at low rpm. We also found that the bike was rich at cruising rpm (5,000) and a hair lean at WOT from 7,000 up.

Solution was to pull a shim from the needles, ending at total shim of .040" front and .047" rear to the stock slides, added the dj style slide hole back (drilled out what i had epoxied shut) and left the 178/180 mains, stock slide springs, 45 pilots.

We left the mains as is - a/f would only go to 13.5, and it was only 43 degrees, so figured they would be good for summer temperature.

The difference is amazing. Wheelies now at almost any mid range rpm in 1st, beautiful smooth roll-on torque.

AndyMX47

After putting another 40 miles on the bike last night, I wonder if it can be even better?

The power and throttle response is great, but I seem to feel a little more vibration than previous, and a little "dullness" at barely open throttle - I mean when you have to fiddle with the throttle to see if its open at all.

Need to check my carb synch, fine tune my fuel screws, but was wondering about the needle shims - is there a benefit to going to one shim in front - total shim of 0.025" (stock is about 0.018") - 0.6MM and keeping two in the rear (1MM)?

Wondering if the slightly different shim stacks help smooth out the difference between the two cylinders?

Think I might be really splitting hairs now, and should quit while I'm ahead. If I had a good way of measuring a/f for each cylinder, I'd give it a try. Considering it would mean two trips into the carbs if I'm wrong - I'll probably give it a rest, and stick with fine tuning the fuel screws and getting my synch perfect - it's about 10mm off right now.

VTR1000F

Too late. You've got the bug.

sjscicluna

weld a bung in each headder to measure AFR then cap it when not in use

AndyMX47

Trust me - I've thought long and hard about using an AEM wideband O2 sensor with a bung in each pipe. Another $200 down the drain, though, for what is likely to be tiny increases in power from here on out.

Especially when I consider my next bike will likely be EFI - hopefully I won't need it anymore.

AndyMX47

Went for a ride yesterday. Small tweaks of the fuel screws, synched the carbs (they were only off a hair) and am just amazed with how well the bike runs now. The $60 in jets, plus the $70 on the dyno was well worth the effort.

AndyMX47

Feeling like a hypocrite (sp?).


Went for a mountain ride yesterday - bike seemed to be having some issues below 3,500 rpm - coughing, just sounded "dead" or "loud" at lower rpm. From 4,000 rpm up - fantastic, but slightly rough. Temperatures in the 80's and humid. I did notice brief times when it would run great, when I was riding through areas up the mountain that were colder. I wonder if I'm chasing a maintenance issue like carb synch (just did them last week) cracking intake boots, or sticking float needles, and trying to fix it with jetting changes? Not sure why the bike would run great one weekend, then not so great the next. 2 1/2 turns out on the fuel screws, 45 pilots, stock needles shimmed a total of about 0.040" (one brass washer plus one stock washer) and 178/180 main jets. I will say from about 7,000 rpm on up the thing pulls like it has a supercharger, so I think my mains are right. Do I spend the $$$ and replace the intake boots and float needles as insurance? They are 17 years old!

AndyMX47

Well, never underestimate the effect a small part can have on how your bike runs.


My enrichener (choke) fittings (the plastic ones that thread into the carb bodies and hold the choke cables) - had been replaced by the PO with a hodge podge of metal bits off of different bikes - each carb fitting was different.


I never paid them much heed during the carb cleaning process, because, well, they were like that when I got it, right?


I ordered some metal replacement choke fittings from Mark off of the VTR1000 board, and decided this weekend to install them. Upon teardown, I noticed that the rear fitting was loose - almost looking like it may have been holding the choke partially on at worst, and/or potentially causing occasional air leaks, at best.


What a difference. 1st, the choke **** now has full length, smooth travel in and out. The rubber boots stay seated on the choke fittings just like they're supposed to. I had to re-synch the carbs because, I assume, I had been chasing intermittent air leaks at these fittings.


After re-synch and replacing the fittings, the idle is much smoother, backfires during decal are much less, if not eliminated, power is as good as ever.


Let's hope I'm done with this for a while, and can just ride!

AndyMX47

50 mile shakedown ride tonight after fixing my choke fittings, and pulling a shim out of the needles.


Much smoother, even slightly quieter. Slight hesitation if throttle whacked when engine is cold, but great response when warm. Partial choke seems to slightly increase response. Amazing performance up top, so much smoother at low rpm and part throttle. Wheelies like a big dog in 1st when whacked at 3500rpm.


Current setup is:


178/180 Mains
stock needles, .024" shims instead of stock .018" shims (i.e. only one washer under each needle)
fuel screws at 2 1/2 turns
45 pilot jets


I think I might add one shim back to each needle to get closer to .040" and see if that gives me improves mid-rpm response any. Seems really close to perfect now. Had no carb farts, no surging idle, bike ran 1/4 to 1/2 on the temperature gauge.


Funny that the jetting is now so close to stock. Duh, maybe those Honda engineers weren't so dumb after all.


My gas mileage also went from 29 mpg to 35 mpg (measured over the course of 50 miles - hardly representative of multiple tanks of gas) so the sticking choke was really messing things up - when it was sticking, which, nobody can really tell. All the time? Half the time? Air leaks when hot?