Aftermarket Exhaust on a Brozz

[goat67]

I just installed the aftermarket exhaust with exhaust wrap.

My impressions, I miss the chrome accents that were on the header pipe and muffler.

The original exhaust is much heavier maybe twice as much.

The aftermarket needs some tweaks to get it to fit around the clutch linkage and the back of the engine.

I do not like that there is not a clamp to hold the two pipes together.

The second pipe runs real close to the frame in the rear.

I thought I had sufficient clearance around the motor but it is to close and transferring to much heat via the clutch linkage and the back of the motor.

I am hoping I can reposition it otherwise I do not know if I will leave it on...

I am running a 108 jet right now with two washers under the clip.

What do you suggest I go to I have a wide assortment of jet sizes
110 or 112?

[JerryHawk250]

Looks good Someone else on here made a bracket to the muffler shield . I would go with a 115 main.
Found the thread http://www.chinariders.net/showthread.php?t=20165

[goat67]

Well I repositioned the pipe. I needed to drill a new hole for the mount.

Took it for a spin and got a backfire does that mean it is lean?

The elevation for where I live is 879 to 1000 ft

I have a 108 Jet in right now. What jet?

[Kivi]

115-120 main jet, for open exhaust with no cat and air filter you have.
If backfires on engine breaking then try to open mixture screw for half turn.

Also, check your kickstarter if it is mounted OK.

[Megadan]

You had close to the same fitment issues I did. I was able to get everything lined up in a way that it didn't contact the motor, but like you that mid pipe mount was just slightly off from where it should be in order to clear everything. I ended up having to remove the rubber isolator where the stock exhaust bolted on, and offset it in the mount hole with a big flat washer on each side to help hold it down. I honestly think that mid pipe and its mount tab cause 90% of the fitment issues.

As far as the Jetting, Kivi is pretty spot on. At least a 115 main should work well, but having the next 2 sizes up can't hurt to possibly dial it in more.

Nice rotated exhaust tip btw. I had to do the same thing lol.

[goat67]

Ok
I a little guidance needed here. I Changed Main jet to 118

Elevation around 900ft temp today is hot around 90

I have for main jets
100 102 103 105 108 110 112 115 118 120 122 125 130 135 140
and for pilot
30 31 33 34 35 38 40 42 45

I am adjusted 1 1/2 out
Idle at 1500
1 washer under the clip in the needle
34 Pilot
118 main jet up from 108 I had in there.

Bike starts up with no choke
Top end has improved and is pretty smoth.
I can pull right thru 8000 rpm

Only thing that I am noticing now is it seems to wants to idle up high I am having to blip the throttle to get it to drop.

I have never been able to get the bottom adjustment to really make a difference. Is 34 to big?

Thanks for any guidance on dialing this in.

[Kivi]

Looks like air leak? Check if you put back everything OK.
Also, after changing main jet, needle, I believe the mixture should be adjusted again for highest idle.

[goat67]

Originally Posted by Kivi

Looks like air leak? Check if you put back everything OK.
Also, after changing main jet, needle, I believe the mixture should be adjusted again for highest idle.

Ya
It helps if you screw down the throttle cable I am amazed it ran at all,
the top was not screwed on at all only thing keeping it in the carb was
how short the cable is.

[Megadan]

A climbing idle like that is usually an indication of being lean on the idle mixture. A rich idle mixture will cause the revs to drop and bog out a bit as it sits there. As far as the slow jet/pilot jet size. Most tuned keihins on the cg250 I have seen run around a 38 to 40

[goat67]

Originally Posted by Megadan

A climbing idle like that is usually an indication of being lean on the idle mixture. A rich idle mixture will cause the revs to drop and bog out a bit as it sits there. As far as the slow jet/pilot jet size. Most tuned keihins on the cg250 I have seen run around a 38 to 40

The climbing idle was solved by screwing the cap on the carb

How should I go about tuning this carb like I said I have not really ever been able to get any difference on the slow jet.

When I first got the bike I changed to a 108 from the 105 and put 2 washers under the clip.

From then on I could start the bike any time of the year with out using the choke.

[JerryHawk250]

I just notice you deleted the airbox. I like all that extra room under the seat. I want to remove mine but at the same time create a storage compartment in that area.

[JerryHawk250]

My stock PZ30 had a K40 pilot and needle shimmed with 2 washers and on my new PWK30 I have a 38 pilot. Needle is on 2nd groove from the bottom.