Possible intake leak?

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superhawk996xx
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Joined: Sun Jul 28, 2013 4:04 am

Possible intake leak?

Post by superhawk996xx »

OK, so I have my bike back together after breaking the carbs down, cleaning them and replacing the jets and float valves. The bike runs great with one exception. It pops on the decel and at idle it occationally sounds like it misfires. I thought prehaps it was an intake leak around the boot to the block. I sprayed on carb cleaner around it and the bike shut off. Could it be something else or am I misdiagnosing this problem.
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VTRDark
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Re: Possible intake leak?

Post by VTRDark »

Intake leaks tend to cause more carb farts/spitting. Popping on decel will be on the exhaust side. The first thing to check is for any leaks around seals.clamps in your exhaust system. The smallest leak can upset things. The PAIR system causes a lot of popping and banging if not removed. I presume you have already removed that, but make sure there are no leaks around this and everything is capped off properly.

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superhawk996xx
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Re: Possible intake leak?

Post by superhawk996xx »

No, I still have the pair system installed and working. The popping occurs during idle so far. Also, I sprayed some carb cleaner around the carb boots and the bike shut off. Is this normal? My exhaust has always leaked at the very bottom of the bike but other than that its good. I will try to get that fixed first and go from there. Over all, the bike runs like new with the carbs cleaned, new jets and float valves!
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VTRDark
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Re: Possible intake leak?

Post by VTRDark »

I can't see why the bike would cut out spraying carb cleaner around the inlet rubber. Even if there was a leak you would have to get a fair bit in to do that. By the way carb cleaner is not a good product around rubber as it rots it.

Any exhaust leaks will cause some popping on decel. I believe the PAIR system doesn't help either. You may want to look at removing the PAIR.
http://vtr1000.org/phpBB3/viewtopic.php?f=9&t=26096

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superhawk996xx
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Re: Possible intake leak?

Post by superhawk996xx »

Yea, the carb cleaner around the inlet boot might not be a good idea. I am stumped by this. I guess the only thing to do is make a list and checking off all possible problems. About the PAIR removal, I have been told it is possible to flip the reeds in the valve covers over and that would shut the system down. could the carbs being out and sync and needing a idle down procedure cause this?
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VTRDark
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Re: Possible intake leak?

Post by VTRDark »

could the carbs being out and sync and needing a idle down procedure cause this?
Not the popping and banging but it would help with the idle, with what I suspect to be a stutter rather than misfire. I'm surprised you haven't done a carb sync/balance already as the carbs have been apart and you have made changes.

First things first, get rid of any inlet or exhaust leaks. You will never get things working perfectly smooth with leaks in the system.

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Pete.L
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Re: Possible intake leak?

Post by Pete.L »

Don't forget there is a half hidden joint in the rear exhaust by the rear shock. It is a favourite for the seal to disintegrate over time and it can cause all sorts of popping and the occasional engine stumble.
Have a look there first and then have a go at rebalancing your carbs as well because of the rebuild

Pete.l
My new ride is a bit of a Howler and I love to make her Squeal
superhawk996xx
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Re: Possible intake leak?

Post by superhawk996xx »

Ok, one more symptom I have noticed while letting it run for a few minutes in my garage. I have notice a small blue flame coming from the exhaust when the popping occurs. Also, I have set the bike up for syncing but do not have the tools to do it. I was going to try to make a trip to my local Honda shop for that being I am fixing this thing to sell it. The thought breaks my heart ::(:
superhawk996xx
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Re: Possible intake leak?

Post by superhawk996xx »

also one more thing. the black knob that controls idle speed. I have that knob screwed all the out, like NOT touching the throttle and the idle is around 1k. wouldn't it be lower? :confused
tony.mon
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Re: Possible intake leak?

Post by tony.mon »

The carb synching circular parts at the rear LH side of the carb often seize together, and this makes balancing almost impossible.
Check that they move freely when you move the balance adjuster.
Re the tickover adjuster, sounds like you have the cable slack set too tight, and this is holding the throttle on.
Try resetting the cables at the carb end after you have taken all of the slack out of the adjuster at the cable adjuster near the throttle end.
Then reconnect the cables to the carbs, and you should have ome, but not a lot, of slack.
Dial that out with the upper adjuster near the throttel, and you should be able to get alow tickover, or one which allows the engine to stall.
But you don't want it set low anyway; around 1300 to 1400 is better.

from what you are describing it's perfectly normal, they always bang and pop on the overrun, and the carb cough/(carb fart if you're American) is normal as well.

Stop worrying and ride it.
It's not falling off, it's an upgrade opportunity.
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fabiostar
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Re: Possible intake leak?

Post by fabiostar »

il be the dumb ass here. the PAIR system? what the hells that :D
the older i get,the faster i was :lol:
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Wicky
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Re: Possible intake leak?

Post by Wicky »

Emissions control system that feedbacks and burns old exhaust gases

Like this....

Image

Recent thread on PAIR system removal > http://www.vtr1000.org/phpBB3/viewtopic.php?f=9&t=26096
It may be that your whole purpose in life is simply to serve as a warning to others.

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superhawk996xx
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Joined: Sun Jul 28, 2013 4:04 am

Re: Possible intake leak?

Post by superhawk996xx »

Wicky, I think you are right about the throttle cables having too much tension. I am going to take the tank back off and reset them. I thought I had them just loose enough. I have been running this bike in my garage for about 20 minutes and day and I can tell a huge difference in it with each day. I had alot of gas in the oil when I changed it so I am assuming there was alot of gas still in the engine I could not get to with out running it and letting it boil off. The popping is starting to whine off as well. I am going to try to make a carb sync tool with clear tubing and go from there. Anyone have any suggestions where I can get GOOD instructions on this? As for the PAIR system I am going to leave it. When I started this project, I noticed the PAIR valve was not even hooked up from the last time I took it to have it worked on. If I decided to keep it, I am going to look into removing it.
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