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Discussion Starter #1
Mine (a 94's) is backfiring a lot, why ?, I know that my friend who has sold it to me, had decided when it was his own, to get it a little bit more "present" (noisy).
So hes has made some (one per side) 20mm in the center of the muffler.
So now, I think that's why it's backfiring.
But the issue is that I have tried to close the holes but I didn't succeed.
The consequences are : little more present :) , but explosions when I decelerate :mad: , and tendancy to be hot (too hot), and when it's hot the engine hurt a little bit.
In fact in the morning when the engine is cold, it's the best feel I have, the engine seems to be happy, round, sweet and "torqy"

So my question is : how to make it as when it's cold ?
re-jet
airmix screw
change the mufflers ? :doh:
 

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HAWK
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2,576 Posts
Is the Reed valves still intacted? If so I would remove or plug them, then adjust the mix screws. What other mods have been made, is the Premuffler (goatbelly) still intact? Have you instaled a new Maint free batt, or checked your voltage?
 

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Uber Member
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yeah, i would say reed valves too.... sounds like in the heat its either hot enough to burn the unused fuel, or there is just enough unused fuel that the denser cold are helps burn more.... we need more info !!!!!
 

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If tou turn up the idle adj. so the tach is around 1250 rpm to 1400 rpm that will reduce popping.A lot of people dont like thier idle that high.
 

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lol i know i dont, i acutally turned mine below 1k :p he he he..... one plus with the higher idle speed is less battery drain at idle lol
 

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and the Adventure Cycle
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Hizzo3 said:
i acutally turned mine below 1k
That's how i have mine too. But just barely below. Occationally it'll almost sound like it's going to stall (while sitting at a redlight) but the Vulcan keeps on runnin' !!
 

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Discussion Starter #7 (Edited)
mods

In fact no other's mods, the goatbelly is there, the reeds too, just the mufflers a little bit more open.:wow:
I've noticed that , like today, this morning was 17°c she runs perfectly :notworthy , start without choke, but needs choke to keep alive (middle), this afternoon around 29 , awfull, the engine is rough, intake noisy (grrrrrrr) not as round ans smooth it is in "cold" mode.:confused:

The iddle is 1k rpm

for the batt, in france I can't find a maint free batt:hitanykey , so it's a new one but...voltage is ok

I've some hot starting issues also, when I stop to refuel she's accept to run only if I walk with her, pushing the start button and on 1st gear "playing with clutch".

I don't know if all these problems are linked but it seem that when the T° increase the carburation is to lean (backfiring, and getting hot, and not sweet engine)

Does the reeds play also on normal throttle (on ride), or only in throttle off ?
does the air mix screw involve in the not iddle mode ? or only at iddle ?

for me the main pb is not so much backfiring but the difference between 17°c and 29°c, between a pleasant engine, round running ;) , and a rough engine, hurting :loser1:

just a remark more,
when I've tried to close the holes he has done, it was better...
 

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Once Banned
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2,125 Posts
I can tell you that your hot starting issues are due to the battery. Ordering a maintenance free battery over the internet may be your only option. The battery will also prevent backfires when starting. It doesn't matter if the voltage is OK on your current battery. There is only one battery designed for the bike that is not maintenance free, and that is the Yuasa. All the others may fit, and the specifications may say for the Vulcan 750, but they don't work well with our electric starting system.
 
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