Higher Speed Lag and Spark Plug question

I

iSack1L

Been Around the Block
Hey all. Any input on this question is appreciated. As some background, I started with UNI pods (the red ones) installed on my CB350 twin with stock jetting and it was running pretty crappy at high speeds. I bumped up the main and secondary main jets and it seemed to run a bit better. However, I'm still not getting anywhere above 60mph or so with full throttle. So I'm looking for input. Basically, as a relative noob, I'm not sure if I am leaning out or running too rich with the throttle open. Just looking for some input on whether to go back down with the jets or up further. I had adjusted the timing and valves before and I thought my compression was good.


The other problem is that I have been fouling plugs. I assumed greater air (b/c of the pods) necessitated bigger jets, but the plugs are fouled and I can't get a good chop to figure out where I am at. So, I am going to start from scratch again. I am going to get some new plugs and I was hoping also for a recommendation on that. I have dyna coils and wires and I don't feel like the spark I'm getting is as big as what I expected with the coils. Perhaps I need a better plug? Also, is the gapping different for the plug with the dynas? I know some people with the Dynas ran Iridium plugs or the NGK B7ES plugs. Any thoughts on that would be greatly helpful.


I'm going to go through the motions again from valves, to timing, to compression and probably another jet adjustment. But would love your input beforehand. Let me know what you got. Thanks guys. :D


Isaac
 
On a related note, I have been running my Dyna coils and wires without a resistor cap. I was told I didn't need it. Is this OK?
 
You probably need resistor plug caps, they actually improve spark (it has to be a higher voltage to get through resistor)
Very doubtful you needed bigger primary mains, airflow through stock filters is close to atmospheric at low rpm.
You will need bigger secondary mains, start around 115
 
Thanks PJ. I have 115s in there right now. Would you recommend regular NGK resistors? Also do you think a hotter plug would help like the B7ES?
 
Anyone have a plug recommendation and/or thoughts on whether the gap would be to spec if I bumped up the jets and changed the coils?
 
People swear by iridium plugs.....but even normal plugs should get you over 60mph. And the gap wouldn't change - it's set to create ideal spark for that plug. Not the tuning characteristics.


Good luck man.
 
Another thought is to check your float height and make sure you're getting adequate fuel flow. At higher speeds it might be starving out.
 
I'm running B8ES or B8EG with 0.030" gap and standard Honda coils/points on my 360 (378cc)
I think your jetting is way too rich, re-fit stock pilots and primary mains and try 110 secondary mains.
Drop needle one clip if possible *haven't messed with CB350 stock carbs for a long long time, forget if needle is adjustable?)
Check battery voltage when running and check voltage to ignition coils
 
These carbs dont have the capability to adjust the needles like that. I think some people shim them, but I haven't gone that far. I will do as you suggested with the 110 secondary mains this weekend. Also, should float level be at spec or different because of the larger jets?


Thanks.
 
Don't shim needles, it makes it even richer mid range.
re-set float level about 0.5mm higher and see if there is an improvement.
You can go 1mm higher if you need to.
If 115 is too rich, you want to try 112 and 110, pods make carbs very susceptible to small jetting changes
 
I'm runnin pods on my 360 with short mufflers. I put some 110s in the other day and its running rich. My plugs were so fouled that the engine would not start back up when it was warm. So I got some 105s in the mail. Hopefully that will sort it out. It just blows my mind that such a small hole can make such a difference in how the engine runs cause with the stock jets at 100 it was running pretty lean.
 
No kidding. Stock for me was 105 though. I have the 110s already and will bump it down this weekend. I am going to recheck everything though (timing, valves, float height), because I'm sure my previous noobish adjustments were a little off.
 
skatetheame said:
I'm runnin pods on my 360 with short mufflers. I put some 110s in the other day and its running rich. My plugs were so fouled that the engine would not start back up when it was warm. So I got some 105s in the mail. Hopefully that will sort it out. It just blows my mind that such a small hole can make such a difference in how the engine runs cause with the stock jets at 100 it was running pretty lean.
Click to expand...

Depending on how restrictive mufflers are, 105 jets should be lean at top end on a 360
I've found even 107.5 are too lean to run properly with a free flowing exhaust (not a loud exhaust, just free flowing)
Mid range will still be rich without air correctors
 
That's what I thought. That's why I got the 110s. I don't think I have the screw in air jets tho. :-/ Maybe I could drill them out tap them and get some screw in ones from you? Idk I'm just hopin the 105s will let me get it to idle right.

Also the mufflers don't have conventional baffles I'd never seen something like them before but then again this is my first bike. It's hard to explain how they work or look but they are the Emgo 15" tapered mufflers I'll post a pic after I get off work.

Also sorry for the thread jacking that just occurred haha.
 
4aab42f5-46fe-b951.jpg

Ok so here's the inside of the muffler. At the header it bottlenecks to one side and flows from those holes on the outside of the pipe
 
Don't know how restrictive (quiet) that system is but you'll probably be fine with slightly larger than stock jetting. Can you get a similar picture of spark plug?
 
While I had the pipes off I ran it for a while with straight pipes and it was really loud. The mufflers quiet it down a lot. The plugs are a good tan color when I'm runnin down the road but they get fouled pretty easily when it's idling or in stop and go traffic. I have some 105s in the mail so hopefully that will straighten it out at least where it will return to idle normally so I can get through town.
 
Were are idle screws set?
further in will lean out idle, further out richens it.
Start at 1 turn out from lightly seated and try 1/4 turn at a time either direction
 
Oh yeah with the 110s in it now the idle screw is an eighth out from fully seated and it's still running rich. I've got some new plugs that I will be using to test with tomorrow tho because the ones in there now are in pretty bad shape. I think with the 105s I'll be able to dial em in with the pilot screw.
 
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