Lack of power/bursts of power

[Chaz]

I wonder if your muffler needs cleaning. I think you mentioned that there was oil dripping from it. Degreaser or solvent rinse. You can try loosening up the exhaust flange nuts to get 1/8 inch gap and see if that helps you fire up.

Also I think my ignition is a little weak so I have my plug gapped at .022 and seems happy with that.

Again, 24:1 may be a bit heavy for your engine. It's safe to go with 32:1 and that just might make the difference. Worth a try.

 

[D.Knight]

I wonder if your muffler needs cleaning. I think you mentioned that there was oil dripping from it. Degreaser or solvent rinse. You can try loosening up the exhaust flange nuts to get 1/8 inch gap and see if that helps you fire up.

Also I think my ignition is a little weak so I have my plug gapped at .022 and seems happy with that.

Again, 24:1 may be a bit heavy for your engine. It's safe to go with 32:1 and that just might make the difference. Worth a try.

I've tried both the stock and the performance one, which I hit with air when I took it off

 

[Greg58]

Ok, does the plug ever look wet? If it does check the magneto, if not check for a fuel restriction.

 

[crassius]

I've had bikes come in with idle screw set so high that it wouldn't start - loosening it and using twist grip to feel for where it wants to start helps.

 

[D.Knight]

I adjusted idle max out and then quarter turn in every failed start attempt; still nothing. Plug does occasionally look wet. I tried putting fuel mix down the spark plug port, knowing that I'm getting spark, and it didn't even pop. Is it possible the spark isn't strong enough? I've tried 3 brand new plugs all gapped differently. Clutch is engaging as well, so it's not that, and I'm getting 160 psi compression. So fuel, spark and compression are there, what am I missing?

 

[Greg58]

Are the magneto to CdI wires making good contact? Make sure they are a tight fit. Did you happen to ride it on a wet road? If so sometimes water will get in the left side cover and short the magneto, also clean the ground wire on the magneto, I've had problems there before.

 

[crassius]

if it were here, I'd either put CDI on my tester or just plug in a fresh one, seen them spark well but at wrong timing

when it seems this hard to get such a simple motor to start, I often start over from scratch as it is easy to be looking right at something wrong and just not realize it

 

[D.Knight]

if it were here, I'd either put CDI on my tester or just plug in a fresh one, seen them spark well but at wrong timing

when it seems this hard to get such a simple motor to start, I often start over from scratch as it is easy to be looking right at something wrong and just not realize it

Crassius with another win. The only thing I didn't replace was the cdi. I thought because it had the NGK on it, it was superior and couldn't have been the issue. To my dismay, I was wrong and was the root of my frustration the entire time. Thanks again to everyone for helping me troubleshoot this issue. Hopefully someone else will benefit from all of this.

 

[Greg58]

Good to hear you got it running, I keep a cdi, magneto and carb as spares just in case.

 

[D.Knight]

Good to hear you got it running, I keep a cdi, magneto and carb as spares just in case.

Yeah I do the same, I just didn't think cdi since I was getting spark. I thought the magneto dictated when the spark occurs all on its it own

 

[Greg58]

The magneto creates the spark and triggers the discharge, the cdi is the capacitor that stores the charge until its triggered.

 

[crassius]

component inside CDI determines timing of spark

 

[Greg58]

Several people have aftermarket cdi units that some say work well, while others say they reduced the rpm. I've built a couple that I think improved over stock but not enough to satisfy me, the handmade look made my bikes look bad. I like the compact stock cdi for my use, I'm not after high speed and do not race my bikes. If I can ride in the 25 to 30 mph range I'm satisfied.

 

[D.Knight]

Yea I noticed what feels like a good 3 to 4 mph slower with the stock one on. The aftermarket one that I had only lasted about 25 miles.

 

[D.Knight]

Okay, so now back to the lack of power issue that was the reason I started this thread.

I feel like I'm getting robbed of power somewhere. I have an hp carb, expansion chamber exhaust, throttle is opening all the way, I tried the 3 prong spark plug and it was a downgrade from the ngk bp6hs, and just put on a boost bottle which made my power very choppy so I'll be reverting back to stock. I've gone through 5 tanks of break in mix, and am now at 40:1, but nothing seems to help. I'm only able to go about 23 on a level road (I know this thanks to the man and those speedometer speed limit signs).

Any and all suggestions, comments, ideas, or remarks are welcomed.

 

[crassius]

I've kinda lost track of what all was done here - but my usual advice is get everything back to standard and see what happens.

 

[D.Knight]

I've kinda lost track of what all was done here - but my usual advice is get everything back to standard and see what happens.

My last post pretty much sums it up, but I was going to put everything back to stock tomorrow and see what happens.

 

[Greg58]

D something is holding you back, my 48cc with minimal performance upgrades will do 30 on flat roads, that's with a 44 tooth rear sprocket. I've trimmed the piston for port clearance, a little porting and a modified stock exhaust . This is with a stock nt carb. I have got 32 out of a different motor using the cns2 carb but got tired of the carb bushing problem.

 

[D.Knight]

D something is holding you back, my 48cc with minimal performance upgrades will do 30 on flat roads, that's with a 44 tooth rear sprocket. I've trimmed the piston for port clearance, a little porting and a modified stock exhaust . This is with a stock nt carb. I have got 32 out of a different motor using the cns2 carb but got tired of the carb bushing problem.

I've been wanting to take the piston to the bench grinder after learning that it doesn't clear all the way and I have a spare piston and company in stock. But would that restart the break in period? The reason I haven't done it yet is because I don't know the answer to that question. I'm using the stock sprocket which I believe is a 44. Also seems I have a vacuum leak which only shows itself after a long ride. I've sealed everything on the intake, where else can this come from?

 

[Greg58]

If you are using a stock head sanding it on sandpaper taped to a thick piece of glass will help seal it. I've had a couple that leaked badly. Check both ends of the crank for fuel behind either cover, fuel means a leaking seal. Also look around the base of the cylinder and the crankcase halves for signs of fuel. One of the most common leaks is at the carb to intake.