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The 2-Stroke Garage => Turning Wrenches => Topic started by: KANDY on May 20, 2021, 06:58:13 PM

Title: What is the Recipe for Bottom end Power
Post by: KANDY on May 20, 2021, 06:58:13 PM
Hi All,

Happened to ride someone else RD350 last week and found my RD is missing bottom end power , take off from stop feels like it does not get enough gas. At 4000 on wards it is running to my satisfaction.

Checked if it is the clutch slipping, and found it is good. May I know what makes bottom end power for RD350. High top Carb.

Also I have to put 22.5 pilot because 25 was giving maximum RPM at 2.5 out on Air screw. And 22.5 is giving at 1.25 out.

Bike start cold at first kick all the time with choke and without choke afterwards. Needle positions were tried in middle and one down rich side. Middle was giving me bogging so tried one slot

down and running good. Running on Points and timing is spot on 1.8 BTDC. Using K & N with Y Boot

Picture of Brand new plug ran for 50 miles with this setting attached. Mostly from 1/4 up to 3/4 throttle.

Title: Re: What is the Recipe for Bottom end Power
Post by: KANDY on May 20, 2021, 11:57:51 PM
 :help:
Title: Re: What is the Recipe for Bottom end Power
Post by: Jspooner on May 21, 2021, 12:00:34 AM
It would help to know what you've done to it already.
Title: Re: What is the Recipe for Bottom end Power
Post by: KANDY on May 21, 2021, 12:04:53 AM
Nothing much, Squish has been corrected to 1.0mm by machining the Head. Stock Exhaust. RZ350 Cross Over Pipe, removed the Locator in the Reed manifold.
Cleaned all ports, but did not removed much material
Title: Re: What is the Recipe for Bottom end Power
Post by: m in sc on May 21, 2021, 10:16:14 AM
try raising the needle one richer.

Title: Re: What is the Recipe for Bottom end Power
Post by: KANDY on May 21, 2021, 10:34:06 AM
Will do it today. That will be the richest possible for that needle.
May i know the part number of the richer needle. Current one is 514
Title: Re: What is the Recipe for Bottom end Power
Post by: m in sc on May 21, 2021, 10:43:37 AM
stick with the 5L4.

if it gets worse, then go back down 2 to middle. try then.

:twocents:
Title: Re: What is the Recipe for Bottom end Power
Post by: KANDY on May 21, 2021, 10:52:21 AM
FYI : Before I tried the slot above the middle position(Lean side), the Bike could not take off.
One Below the Middle position, where I am currently runs very good, but taking off is still lacking.
Hope one more down you suggested, will improve that.

Also I was wondering, 22.5 on pilot and so much rich on Needle, is that a combination, Am I missing something.
Title: Re: What is the Recipe for Bottom end Power
Post by: m in sc on May 21, 2021, 11:05:57 AM
im not sure whats going on with your carbs. very odd settings. but the bike wants what the bike wants.

Title: Re: What is the Recipe for Bottom end Power
Post by: KANDY on May 21, 2021, 11:17:52 AM
Yea, what ever I read and learned is not tallying with this Carb Tuning. may be I will do a thorough Check if it is still not working.
Title: Re: What is the Recipe for Bottom end Power
Post by: sav0r on May 21, 2021, 11:24:03 AM
Make sure the slides are down on the adjusters and not being held up by the throttle cables.
Title: Re: What is the Recipe for Bottom end Power
Post by: KANDY on May 21, 2021, 11:43:52 AM
Will check it for sure.
Title: Re: What is the Recipe for Bottom end Power
Post by: Jspooner on May 21, 2021, 12:14:11 PM
I think you need bigger pilots. You have smaller than stock in it. I'd put 30s in.
Title: Re: What is the Recipe for Bottom end Power
Post by: KANDY on May 21, 2021, 12:32:25 PM
Will try that too in the Weekend. Wondering why the air screw reading is giving wrong indication.

Quote from: KANDY on May 20, 2021, 06:58:13 PM

Also I have to put 22.5 pilot because 25 was giving maximum RPM at 2.5 out on Air screw. And 22.5 is giving at 1.25 out.

Title: Re: What is the Recipe for Bottom end Power
Post by: dugsgms on May 21, 2021, 11:11:05 PM
 Did you ever ride the bike with the 25 pilots before installing the 22.5s?
Title: Re: What is the Recipe for Bottom end Power
Post by: gardenhosebusabottle on May 21, 2021, 11:43:40 PM
I agree w/ Jspooner.  sort the pilot 1st.  Smaller than stock, you are probably leaning out and that is carrying over to the other circuits, confusing things.   you could go 27.5 and then 30 pilot.  I ran a 27.5 pilot in the RD400 w/ Supertune airbox mods (stock bike).

You could try this: put new plugs in the bike....take it for a easy 15 minute ride using some throttle to put some color on the plugs.   Now do an idle speed plug chop w/ bike on the stand and a fan in front...let the bike idle, for say 5 minutes or so, not touching the throttle and then kill it and look at the plugs.

post a good pic for the experts to peruse!

I'd do that.  what say you fellas?
Title: Re: What is the Recipe for Bottom end Power
Post by: Czakky on May 22, 2021, 06:59:28 AM
I don't think letting your bike idle for five mins is necessary. Using the method the OPs stated for setting pilot has led me to choosing the wrong pilot jets on occasion too. It is a good guideline but what is more important is feeling what the bike wants. My opinion try a bigger pilot just because your stuck and not happy with how the bikes running. If it's worse go back. Pay attention to when the jets are giving most influence and make sure you've got throttle position marked on your throttle.