1969 Suziki T500 Misfire

C

Cincy69Titan

New Member
All,

Just bout done with my Cafe Project! 69 titan MkII.
I just rebuilt my 69 T500 with pods, chambers, some port polishing, carb rebuild, hone and rings. 2nd crank it started up! Now after getting it settled in and cycled a couple of times, it wants to pop on the left side. I verified plug gap, point gap, timing etc. All is fine, when I give it throttle it revs good but it is a bit more smoky on this side too.

I did lean out the idle air screw a 1/2 turn but no change really.

I'm running 1 range cold on the plugs and went up from a 30 to a 35 pilot jet.

Any ideas? Before the top end freshening and carb rebuild no popping!

Thanks,

Marion
 
Did you rejet for the pods and chambers? If you didn't, you will burn holes in the tops of your pistons in very short order, no shit. You will have to go several jet sizes larger on the main jets. You should not have to go colder on the plugs. If you are jetted properly, the stock plug will be perfect. If you have not rejetted, DO NOT ride the bike.

Misfire on a cylinder with points ignition could be a bad condenser. I would start there. Swap condensers and see if the misfire changes sides.
 
Early titan with a sub 1500cc gear box need a mod done to them to extand the life of the gear set carefull running that thing. As far as your current issue i thing alpha is correct you rarely see ported 500s with pipes running stock carbs my dads old drag bike ran 39's so at the very least you should throw alot of jet at yours. Hows about a picture of your bike man
 
All,

Thanks for the replies.

In my post I indicated I upped the Pilot jet from a 30 to a 35. This is the primary fuel source for the idle circuit. As for Mains I upped them from a 150 to 160 s. I also dropped the clip on the Needle 1 slot effectively raising the needle to richen the mid range.

I did a search on here and some suggested a exhaust leak? I'm running some new Jemco Chambers and will loosen and re-do, but new gaskets there too.

I'm not riding it and actually have never had it out since I hauled it home from the sellers barn last summer.

I did not have this issue before carb rebuild and top end refresh. Doesn't mean something has not gone to shit. Plugs, points, condensors are new also.

I just got the front fender on it today need to place on the cafe seat and will get some pics up ASAP.

Thanks,

Marion
 
You hadn't mentioned changing the main jets in your original post.

That may not be enough on the main jet. Best way to jet a two stroke is to keep going richer on the main jet until it sputters on top end. Then back off. Keep the needle clip in the stock position until you get the main jet dialed in, then you can move the needle if needed. Sometimes, you will want to go a notch leaner on the needle after you get the main jet right.
 
Oh, and don't assume that your condenser is working properly just because it is new. All too often I have had troubleshooting nightmares because I refused to believe a brand new component was defective.
 
AlphaDogChoppers said:
Oh, and don't assume that your condenser is working properly just because it is new. All too often I have had troubleshooting nightmares because I refused to believe a brand new component was defective.
Click to expand...
Even at work I doubt new parts. I have had 2 bad parts (NEW) in a row...really scratch your head figuring it out.
Electrical components are especially prone to being bad out of the box....
 
People think you are making that shit up when you say a new part is defective. You begin to doubt yourself when the second new part is also defective.

I used to be a computer consultant. I learned from years of experience that unexplained problems were just as likely as not to be new hardware that was defective.
 
Anecdotal :

I have two and maintain another bike that will not run correctly with NGK plugs installed .
In one case the bike will not pull through midrange let alone approach red line in any gear .
Install correct Denso plug and all is right in the world again .

GM 4 terminal module (inside the common HEI Dist) , walk into the parts store with a bad one and walk out with a bad NEW one . Return to the store and 4 of the 6 in stock are duds .

condensers , about 1 in ten over the years are bad out of the box .

CDI box , lately I'd rather a good used unit found on evilbay or Craigs or forums than a "new" non working from a "US Seller" that drop ships from China .

RAM , as in random access memory , about one in twenty bad out of the box .

Flash (thumb) drives , about one in twenty bad out of the box .

Hammer (seriously a fsck'n hammer) Stanley , new , two in a row shed the hammer from the handle in less than 3 hours of use . (note here , Stanley more than made good on this one as well as Home Desperate actually driving a replacement out twice , now that is dedication)

"It can't be the problem it's NEW!!!" Yeah , right , tell me about it ...
There just is not any substitute for complete diagnostic tools. I'm not talking about the ones you buy and loose in the garage I'm talking about the ones you carry around in your head . Exercise (exorcise?) that mush between your ears once in a while and don't rely on "shotgun repairs" .

~kop
 
AlphaDogChoppers said:
Oh, and don't assume that your condenser is working properly just because it is new. All too often I have had troubleshooting nightmares because I refused to believe a brand new component was defective.
Click to expand...

It's happened to me often enough I check the new part first now. Just happened to me replacing the screen on my wife's iPhone 4S. And that's a bitch of a job to do let alone three times.
 
All,

So far I have not done any changes to the engine. I'm adding a pint of gas at a time and running the motor. With rpm around 2500 to an idle of 1400 rpm with throttle blips. Seems the issue is improving but I may have an air leak with the idle after engine warmup finally settling in. Getting left cyl fire immediately now with a lesser popping. Maybe the rings are still seating? Throttle is very responsive and left and right exahust note are becoming uniform. The Jemco's are sounding stout perhaps a video soon. Ear plugs may be needed! ;D My seat is on but may be a inch or two to high. May have to rearrange. I got a seat from V Nam completely upolstered but cafe style on stock NOS pan.

No liscense, tail lights, mirrors, and a leaky front tire. But for the first time may run it down the 1/4 mile street/cul de sac to shift it and kill some bugs althought it is January!!! I want to test the clutch now and get it in a few gears and brake it to see what happens.

Stay tuned or in reality get it tuned!!! Let's hope is doesn't wheelie or cross up the forks! I selected a 39 tooth rear sprocket so it ought be decently quick.

Overall, going to let it settle in a bit more before I go on a hunt! Plugs look good for the rpm so far.

Marion
 
Ok here she is!

T500Jan2013_zpsf2936241.jpg
 
That's a beautiful titan man! I too agree that 160 is probably not enough on the main jet, I'm thinking another one or two up. I had to go up 5 jet sizes on mine and had the same issue.
 
I have a 162.5 in reserve. I guess it wouldn't hurt to put it in. I drove the bike for the first time today since I picked it up. The clutch was good and it went in and out of 2nd no problem. I only went 25 mph maybe up my street and back just to get it to roll and hear the gears.
 
Ok I got the idle fixed.

I resynched the carbs, tuned the air screw on each side on a single cyl, and changed the plugs fro a B8HS heat range to a B7HS. Starts easy and just cackles away now.

Took it down the street for the 2nd time and it won't hardly take any throttle. I'm figuring now that I will undo the Needle adjustment, tweak my float levels, and go up a main jet to a 162.5.

Marion
 
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