The Purrfect Project (Hellcat)

[deadwood83]

Exhaust, YSS rear, and TBolt EZ-Start CDI went in today. EZ is an understatement. THis thing fires up like it's fuel injected.


Brother helped me with the shock by holding up the rear of the bike while I quickly swapped with the stocker. The difference is MASSIVE. A lot of the badness I was complaining about with the handling is gone with the rear shock. Suspension still needs work, and I need to put that Grom swinger on, but waiting for my NDC chain adjusters to arrive before doing that.



With the exhaust, the bike is an entirely different beast. ALmost all the vibration is gone. I really struggled to believe it when people said the stock muffler is half the reason these bikes shake, but it is 100% true.


Gratiuitous shot of post-install ride. Had to feed the inner (and outer) fat guy with a quesarito and crunchwrap supreme. First meal of the day, and the last.



Bike is still louder than I like. KP mini sounds amazing with the kepspeed can, but I don't want to be behind it at all. Sadly that might be the norm after this weekend when the KP gets a 223cc Big bore kit.



Really quite happy the KPM200 deal fell through. The KP Mini is absolutely amazing. If I knew what I do now, I would be rocking the KP Mini.

[scoot newb]

I am going to get a KPM for sure. I am done with the clone and the janky ZS / Daytona horizontal style china motors. I've lost 5th gear.


You can get the 223 kit here

https://www.facebook.com/Plug-and-Pl...c_location=ufi


If your in the group, check out the post about the KP in ZS190 Swap Shop. I thought the dude may have been you. He said he had a hellcat and his bother had a KP mini.

[scoot newb]

What happened with the MZS levers locking? Which ones did you have the problem with?

[deadwood83]

Alllllright. I've gotta document this here for posterity.


2020 Hellcat forks. They are not the same construction as the Vader forks at all. On Friday, I got an a-frame ladder and a 4" wide ratchet strap expecting to change my fork oil. Oh boy was I ever mistaken.


For reference, you can see the general construction of a boom vader fork (at least the endcap and damping rod) here.

I went into the project expecting the same. Nope. I... did my usual and sis not take any pictures, so I will assemble what I found from stock images of chinese forks.

The top cap comes off, and nothing to to it. Nothing attached either.


Inside, I found the heart of the operation. A single 6mm allen head bolt.

With forks mounted in triple, axle through bottoms, I started to loosen the allen head bolt. It just spun.


Okay, maybe it's like the XJ where the internal plug is seated with o-rings in grooves, and it just requires some force to push the plug out. SO I dropped one fork, put it on the ground, loosely threaded the top cap to prevent parts flying out with the force of 1000 angry squirrels, and bottomed out the fork. Nope. Nothing. Not one iota of movement.

Hmmmmm. Maybe spring tension is holding an internal fastener? Removed fork cap, bottomed out the fork, spun the bolt to the left..... nothing. Just spun. Could hear a spring spinning too. Hmmmmm. Okay, what's on the bottom? Maybe it's like an 80s conventional fork where the damper rod valving is secured through the bottom.

Okay, interesting, there is a deep-set 8mm bolt perpendicular to the axle running up into the body. I found an 8mm allen that fit, put that on my pneumatic impact and.... chug-chug-chug-chug... nothing.


Okay, maybe there's loctite? Heated the bottom tube to 150F, just to soften it a little. chug-chug-chug-chug... nothing. This will clearly take a breaker bar and a bench vise. I have one, but not the other (sturdy mounted bench vise with a fork tube holder jaw set). No spare forks in case I bend the tube, so I gave up and put them back together. I have been defeated. That said, I have not bottomed out these forks like many others have reported.I'm at a loss as to how to get these apart.






Okay, onto the other issue I have been fighting. Breakup at 7k rpm. When it hits the trouble spot, it feels like the engine dies, then the momentum from being in gear and moving bump starts it, then it dies, cycle repeats perpetually. I never had this issue with the stock exhaust, only after I added the free flowing aftermarket exhaust. At first, I thought it was just a lean issue. SO I started on a quest for main jetting. I went:

• 118 needle clip positions 2, 3 ,4
• 115 needle 2, 3, 4
• 120, needle clip 3
• 122 needle clip 3, 4
• 125 needle clip 3, 4

None of these helped. I am at 4400 ft elevation and other ZS190 owners report using 118-120 at about 1000ft above sea level, so the 125 is definitely rich. Even then, it should be shooting backfires, spitting, etc even though its rich as a pig. Nope, same cutting behavior.


Well, maybe a vacuum leak. SO I set it to idle and did quick spurts of brake cleaner at:

• the carb manifold connection.... no extra revs.
• The carb boot to manifold.... no extra revs.

Nope, not a leak on the intake. Maybe an exhaust leak? SO I checked the header. Tight. No carbon deposits, no evidence of leak. I used a genuine Grom gasket.


If it were compression, the bike would not start easily nor idle. That's ruled out. So I have ruled out the suck, the squeeze, and the juice. ALl that's left is the spark.


Re-gapped the plug, no dice.
New plug? No dice.


I suspect the ignition coil is the culprit. It's the stock hellcat coil with loose-fitting rubber insulator and stamped steel outer boot. It honestly looks like what you would find on a cheap lawn mower or roto-tiller, or an American yardwork engine from the 60's.


A word on CDI ignition:

Originally Posted by elprocus.com

When the gate opens and dumps all the current into the primary side, it saturates the low-voltage side of the transformer and sets up a short but immensely magnetic field. As the field reduces gradually, a large current in the primary windings forces the secondary windings to produce extremely high voltage.
However, the voltage is now so high that it can arc through the air, so rather than being absorbed or retained by the transformer, the charge travels up the plug wire and jumps the plug gap.

A word on ignition demand:

Originally Posted by agriculture.com

The ignition system is considered to be passive. The spark plug only takes from the ignition coil what it needs to create an arc across the plug’s electrodes. It must be recognized that ignition demand is determined by the following:

• Cylinder pressure
• Engine speed
• Air-fuel ratio
• Ignition timing
• Spark plug gap

Cylinder pressure is not meant to be confused with compression ratio. Cylinder pressure is the cumulative result of the load on the engine in relation to the volumetric efficiency and mixture strength. Compression ratio is a design function of the difference in the volume of the bore with the piston at bottom dead center, compared to when it is at top dead center. Cylinder pressure and ignition demand are constantly changing with engine load.
At idle, the required energy to arc the spark plug is very low since the cylinder pressure is minimal. This is due to the throttle being almost closed, the engine rpm being low, and the fact that there is no load on the engine.

Here is what I am feeling, courtesy of some guy on youtube. This I think confirms the spark issue. It starts around the 1:46 mark.



So the plan of action:

• Re-jet back to 120m clip 4. Likely still a touch rich, but a leaner mixture is easier to ignite (hence why you get pings/knocks when lean)

• Swap in the ZS190 coil, which has a normal plastic and rubber insulated boot. I have already gone through and done the "righty tighty" on the wire at both ends for this coil and plug boot. Typically these just have a pointed screw at each end of the wire to tighten. The screw tends to "fray" the inner conductor of the plug wire, wrapping itself in the copper and making contact.

• If that does not work, I will try an NGK iridium plug CR9EIX. It has a much smaller electrode tip (.6mm vs 3mm on the CR9E) which requires less voltage to jump the gap due to a more concentrated ionization force about the smaller tip. Either the stator is not charging the CDI capacitor fast enough at high RPM to generate sufficient voltage (seems unlikely since RPM and voltage output should be proportional) or there is still a weak link that takes less voltage to jump compared to the cylinder under compression.

Oh and about the plug cap shown above... our plug caps should be non-resistor type, since the plugs used have internal resistors. That plug cap is more applicable to my XJ internally since it uses non-resistor plugs.


The coil that came with my ZS190 ohms-out at .5-Ohm primary and 9K secondary. Haven't take the one off the hellcat to measure since it's been cold and rainy.

[scoot newb]

Were you changing the plugs between jet tests?

I found my plugs were 'fouled' out from running rich and it still ran weird after leaning it out until I put in a fresh plug.

I re-jet, let it warm up, put in new plug then test

[deadwood83]

OK, it was not the ignition coil and plug. Replaced both. The Hellcat coil plug wire pretty much fell out when I removed it, so I was confident it was the culprit.


The issue started when I put on the rear shock, exhaust, and TBolt USA CDI. I would prefer not to trace out all the CDI contacts from sources with a multimeter, so I have swapped the Hellcat CDI back in. IIRC the older ones used to have 8500rpm limiter, but if I find myself hitting 8500rpm then that would tell me all I need to know.


Been working on the KP Mini quite a bit. It ran briefly with the 70mm BBK, and it felt like it pulled hard. Then the exhaust valve seized open, and bonked the piston.



I wanted to brace the engine more. Using MotoCheez' video on bracing his Hellcat I thought I had the perfect answer...


The brackets don't line up perfectly, but the top hole seems to align with the rear motor mount. Sadly, the bottom relief cut for the rearset mounts is too high to make solid contact. This leaves me with two options:

• Mount the brackets using the rear hole and the bottom 4 bolts to the engine, then weld to the frame. (I have no welder, nor friends who can do this)
• Mount the brackets to the engine and rear mount, then drill the second hole location and use the cross-bolt with sleeve.

Option two seems like a good one, since it would relieve some stress from the rear mount and supposedly reduce vibration per the Cheez himself after he welded in his mount.


NDCustomz finally delivered the chain adjusters. I would be ready to swap swingarms except.... BikeBandit has not shipped my order of Honda Parts from 20 days ago. I might mount it up anyway since the new chain tensioners would allow more rapid replacement of the hub/cushions/bearings/axle. Removing the swinger would also be a good time to drill/mount the cradle.


The more I fuss with the carb, the more I feel the desire for EFI. I felt the same way with the XJ as I was dialing it in.. but putting EFI on a single cylinder 1-1 exhaust bike is way more doable than a 4-cylinder 4-2 exhaust bike which would require 4 separate throttle bodies, 4 injectors, etc.


I checked for fuel delivery issues with the Hellcat, and I don't think there are any in the tank -> filter -> petcock -> carb chain. If we assume 80mph & 40mpg then as long as I can drain 1 gallon in under 30 minutes it should be fine. I was able to drain 1 gallon in about 5-10 mins.


I tightened the bar holders to the point the rubber cushions are doing almost nothing. This was a massive improvement. While forks were out I did a 'po-boy/lazy-boy front end alignment. Secured the tubes in the top triple with caps off against a small marble tile, left axles and lower pinch bolts loose, bounced the front end, tightened it all up. Slight improvement. The bike doesn't immediately try to lean/dive to the left if I release the bard while riding. Now it just leans lazily to the left if I release the bars. I can now wave at people without the bike changing course.



Lubing the clutch cable made it ten thousand times better. The clutch actually has feel and springback now! It's fairly light.



Still to do:

• Cry about forks. Stare at ebay listings until my eyes bleed looking for grom forks that aren't priced like the tubes are actually made of gold.
• Ponder if my fat butt really needs bronze swingarm bushings, or if it will just lead me high preload and a sore tailbone.
• Maybe ohm out the whole ignition circuit and re-crimp terminations / solder.
• Actually make a muffler bracket and get rid of my 14-zip-tie braid holding it from the rearset. The zip ties have been incredibly sturdy. They are all at equal tension and woven together.
• Actually finish the oil cooler install. Just need to cut/shape the mounts and finish assembling my lines. Dunno why I am being so lazy about this one.

[scoot newb]

I had the same problem with the TBOLT CDI. I tried it the other day. Within 100 feet I knew something was wrong. It would sputter above 1/2 throttle at 7k. I put back in the stock CDI and even though I am slightly rich, I was banging 9k all day.

[deadwood83]

Yep. I finally got to ride last night (work has been insane) and with the stock CDI it seemed to have no rev limits. Saw 10k on the tach, and eased off because I don't want to frag the crank.



Now I can jet down, because this sucker is running rich with the 125 main. I'll drop to a 118 today and see what's what. I expect to get some power back.



I reached out to Bike Bandit, and was reminded why I never order from them. Even though all parts in my order showed in stock, the gentleman on the phone revealed that for the past 21 days, they have been waiting for parts to arrive at their warehouse. That seems dishonest. I was never notified the parts were not in stock. I canceled the order. If my local Honda dealer doesn't have parts on hand, they let me know up front.


I don't like the fuel tank exit. For now, I have the fuel line/filter looped forward so the low voltage wiring looms keep the right hand side tubing at the same level as the outlet, preserving a downward slope all the way to the carb. I am contemplating doing swingarm and/or oil cooler today

[scoot newb]

That sucks about the delay of your order. I'm not crazy about the gas tank outlet either. I routed mine so it gets slightly lower as it crosses from right side to left then once on the left hand side, straight down.







I ordered another 190 from motorkit yesterday. It was under $700 shipped.

I'll never be able to fix the transmission properly in time to ride this season and nobody else will work on it. I almost got the KP then decided this was a better less expensive option and I could practice wrenching on the inside of the old engine or just sell it for $400 or something.

[RedCrowRides]

I'm bout ready to go set fire to BikeBandits HQ., i ordered 2 Grom rear axle bolts, nuts, washers six weeks ago and still havent gotten them ,and every time i ask where they are all i get is a generic " we are experiencing delays in shipping due to high volumes of orders" reply., with NO indication of when , or if, they will ever get here.


I know now, that was my first and last order with those guys hell i could have ordered them from WeBike thats actually in Japan and gotten them by now.

[scoot newb]

motorkit is crazy fast. Like Amazon Prime fast.

I'm in the US

[RedCrowRides]

Motorkit it is then from now on , I sure won't miss BikeBandit and their shenanigans., thanks for the tip !

[Whisky]

I've always had good luck with Bikebandit, although my last order did take awhile, figured it was a covid 19 issue?

[deadwood83]

I took my first multi-day vacation in half a decade. It's just the next 4 days, but still a big thing. I'd like to take the time to work on my bikes and ride.


Today was oil cooler day. I used a 6-row transmission cooler and made my own AN-4 lines. Had to cut the mounts on both top and bottom, but the fit is really nice. I also had to cut my own mount holes, and mark/drill/tap the HardRacing Grom oil cooler mount.


The bolts go through the cooler flanges, and thread into the oil cooler mount. THen I put some M8 locknuts on top to lock the bolt in the threads in the mount. THe size is absolutely perfect. It fills the void right where the airbox was.




On the engine side, I found some M10 to AN-4 adapters in blue. This should all flow much better than the banjo-based bypass or a banjo based cooler because there will be less pressure loss.


I've always been rather proud of my oil cooler installs. I never seem to go the conventional route on them.

[deadwood83]

Day2 of my time off. I had a swinger party, all by my lonesome. Was a decently good time. The Hellcat swingarm is just... ehhhhh. With better tensioners, it might actually be okayish, but the bushings were already super soft and mushy with a total of 155 miles. The darn thing also doesn't hold shape worth anything. I only took one photo, but it shows half the gap that opens up once you remove the nut.



The Honda bushings, despite having more miles on them, were noticeably stiffer. WHile I was in there, I took the opportunity to apply excessive amounts of moly grease. Wow! What a difference! When I get on the bike I can actually feel the progression of the rear shock, bouncing static I can discern the valving of the monoshock. One positive side effect is that the rear wheel is not as easy to lock up. I believe that is because the suspension can actually travel, and it's not just skidding across the ground.


Bike still leans left when I release the handlebars though. I need to find a piece of plate glass to put across the forks and see if they're actually running true.


After the swinger party was over, I went for a nice ride. Thew thing really does egg you on. They've been putting more of those automated speed reading signs with flashy lights around here. I don't think there was a single one I did not upset. I have the NDC chain adjusters in the grom swingarm and they're pretty nice. Manual measurement between swingarm bolt and rear axle shows the marks on both sides are dead on.



Shifting has improved substantially. It's so much better that I need to focus back on being firm going into second gear. All other gears would probably be comfortable with sandals if you were stupid enough to ride in those. Neutral is also pretty easy to find now, even when the engine is running but the bike is stopped.


On the fuel side of things, I finally got to apply my 10mm colortune adapter. My ears work pretty well, and I always tune idle with earplugs so I can better discern combustion events. Slow circuit was within 1/2 turn of what I consider optimal (blue, with the faintest hint of orange creeping in).


During my ride I did a little seat of the pants shifting. I felt the bike starting to break up at WOT, glanced down, and saw it go past 11k. I could probably go down one size on the main, but I like having my crank in one piece, so a fuel-induced rev limit of 11.5k is fine with me. It's something I struggle with on my XJ. That thing revs so easily you will go from 6.5k to 12k in a fraction of a second. At 12.2 the valves start to float, but the engine will still rev.


I really really really wish I could open these forks more easily. With the rear suspension actually working, if I could get some 15wt oil (read: Redline D4 ATF) in them and get the stupid bike to track straight I would have almost no incentive to change anything.


I think I have thoroughly defeated the purpose of this bike. A cheap, quiet, slow commuter that won't get you in trouble around the city. I guess it's still cheap, and it's slow compared to anything with a 100cc advantage in displacement, but it's pretty neat for what it is. I'm quite chuffed with this little china bike.