No Power 5th Gear

[kyriakos]

Originally Posted by franque

Did you check the intake to see if the gasket was partially blocking the port? I'd also do a leakdown test, too. You can swap CDIs pretty cheaply, maybe it's a bum CDI.

Intake is an O Ring on the Hawk. I did replace that with a new O Ring. I'll look into leakdown test. Never performed one of those, but Google never lets me down!

Originally Posted by Megadan

Does the bike pull hard through the full RPM range in 2, 3 or 4? Does it feel like the engine falls off a bit in the higher RPM range when going through those gears too? It may be a little less pronounced because the load on the engine is lower, but it should be something you can still feel. The engine should pull nice and strong all the way to at least 7000-7500rpm.

I thought it was pulling okay through 1-4, but I've also seen some folks mention possibility of a mini-wheelie... I don't feel there's enough power to hardly bring up the front shocks (much less wheelie) in any gear; I don't feel it's that strong. Though, I'm used to the power band of a 2 stroke, so I have very little to compare to, being my first 4 stroke bike.

Originally Posted by Megadan

I am still curious if you checked the O-rings on the intake pipe between it and the cylinder head. I would also look over the rubber on the intake pipe itself to make 100% sure there is no hole, tear, or crack that may be causing a vacuum leak. It's not unheard of even on a new bike.

I did change the O ring on the intake pipe and inspected that rubber on intake, all seemed okay. The stock O ring was a bit 'flatter' than I had hoped, the replacement was more pronounced.

Originally Posted by Megadan

Have you checked the rear wheel bearings? The 2017's seemed to have a problem with the factory installed bearings being installed poorly and were locked up and almost impossible to turn. My own bike had this issue.

I haven't done this, as the bike seemed to roll freely on ground and jacked up. I could certainly take these down and repack the grease, as I've seen that suggested on a fresh install. This was my plan medium term, but the missing power has been my primary focus before tidying and loctite-ing.

Originally Posted by Megadan

How much slack is in the chain? If the chain is a bit too tight it will also cause some drag. I have found that to get proper chain tension on my Hawk, with the swing arm at full droop you need around 28mm (A bit more than 1 inch) of free play at the center of the chain - or 15mm with the suspension compressed until the chain is at it's tightest.

I'll re-check.

Originally Posted by Megadan

Have you checked the rear brake adjustment? It's not uncommon for some of these bikes to come with the rear brake adjustment just a hair too tight. This causes the rear brake to drag, which in the case of the Hawk is quite a lot of braking force since the rear brake is rather overpowered.

I'll re-check.

My todo this evening:

1. Re-Check Chain Slack (1 inch sitting)
2. Re-Check Rear Brake Adjustment
3. Check Bearings / Repack Wheel
4. Leakdown Test

Note: I've also got a 27.5 pilot on order for the VM 26

If all checks out, I'll order a spare CDI. Should I stay stock on that, or is there a 'better' CDI out there?

[JerryHawk250]

Very puzzling. Everything seems to be checking out okay that you have done. When you did he compression test, did you have the throttle in open position? I would do the leak down test. Have you tried a 115 main? May be loading up on fuel.

[kyriakos]

Throttle was fully open. Is 150 PSI within spec?

I've tried with the factory 98, 110, 115, and 120 mains. Behavior is very similar across the board.

I've gone ahead and ordered the All Balls Racing bearings, I'd rather those be quality anyway, and it's a good time to replace while the wheels are off. Has anyone replaced the coil/CDI with anything other than factory? Would it be worth going with a programmable CDI?

(At this point, I've swallowed the pill to replace the cheaper components to weed out potential issues.)

[JerryHawk250]

Compression should be around 175-180 psi. But being that the engine is new and rings have not had a chance to seat it could be lower. Even at 150 psi you should still have good bit of power.

[JerryHawk250]

FYI on the programmable CDI. It is a DC CDI and will require swapping of other electrical components to convert from AC to DC.

[Weldangrind]

I recommend a stock-style CDI for now. After you get the bike running properly (so as to set a benchmark), you can experiment with racing CDI's.

[timcosby]

might of been asked already but did you look into the end of the carb and move choke to see where open is? when i had oem 15/50 gearing i could do a wheelie in third gear but no it wont pull the wheel up by just twisting the throttle. you have a restriction or something bad with the electronics.

[kyriakos]

Just measured the Pickup/Exciter:

pickup - 180 ohm / .14 VAC
exciter - .023 ohm and slowly climbs over time held / 35 VAC

All of this seems low to the specs I've found, stator issue?

Forgot to mention; not sure what it is, but looks like some kind of oil has found its way into the wire harnesses.. Maybe they had the bike sideways and leaked oil over, then fried the stator?

[kyriakos]

https://photos.app.goo.gl/VppYueHKWsgtyuBt6
https://photos.app.goo.gl/Dwg8wR66qUWxPnCz1

[timcosby]

they may have put dielectric grease on the connections????

[kyriakos]

Budget Power Sports appears to be responding to warranty after threatening to stop payment... I've requested a new CDI, ignition coil, and stator.

I swapped back in the 15 front sprocket and loosened the chain, similar issue in no power around the 50 mph mark, and no particular 'bite' in any gears. New pilot jet arrives today, along with the wheel bearings. Also confirmed no drag on brakes, replaced brake fluids while I was at it.

[JerryHawk250]

Originally Posted by kyriakos

Budget Power Sports appears to be responding to warranty after threatening to stop payment... I've requested a new CDI, ignition coil, and stator.

I swapped back in the 15 front sprocket and loosened the chain, similar issue in no power around the 50 mph mark, and no particular 'bite' in any gears. New pilot jet arrives today, along with the wheel bearings. Also confirmed no drag on brakes, replaced brake fluids while I was at it.

Hopefully it is just a bad CDI not advancing timing as it should. Funny how when it's your money they don't care but when it comes to there's it grabs there attention real quick.

[Cravin01]

I'm really surprised that you still have this issue with all that done so far, my bike easily climbs to 60 before it drains out the last few MPH. This bike should too.

[kyriakos]

A bit of an update. The company shipped out new coil, stator, and CDI. Made each of those changes (1 at a time), but the performance increased only a slight amount.

I've ordered a leakdown tester (can't find one around here for smaller plug threads). This thing is driving me batty, pretty much all that's left are ring/piston/cylinder/head internals, and rectifier. The rectifier seems alright though, battery voltage goes up within range while running...

I'm going crazy to get this thing resolved.

[JerryHawk250]

The leak-down test will let you know if there is an issue with the valves , cylinder or rings. If so, it sounds like a new parts or engine from the dealer.