popping from exhaust front cylinder

[kidastra]

ok long story short, bike was stored for 4 years, finally decided I wanted to get this bike running again.
first no start issues, cleaned the carbs and replaced rear float and set height.

starts and runs easily now, and will continue to idle, the popping gets worse if I give it throttle.

problem is I have a popping coming from the exhaust (aftermarket) same exhaust as when it was running 4 years ago.
the popping is only from the front cylinder, no popping whatsoever from the rear.

I have not done a carb sync yet, but I'm not positive I need one as I just removed the cables but did not touch the 10mm lock on the cables and replaced the cables exactly as I found them, I will do a sync before I take the bike out but want to figure out the popping first.
I did try removing the boot going to the air filter to see if any change in the popping and didn't notice any difference at all.
don't see any leak in the exhaust, not sure if I have a vacuum leak cause I don't know where I would need to check.
while the boot was off, I did notice a random mist of fuel come from the top of the front carb. not constant but it was there when I gave it throttle only

any help would be great.

last thing is this site the old intruderalert site?

[Lechy]

Try replacing the crush gaskets on the header to block.
[emoji41]

[YoDude]

last thing is this site the old intruderalert site?

This site was borne because of the old intruderalert site. They kept having problems with crashing. This site was created because of that particular issue. While we are not the original IA, most all the members here are from there, including myself. We're going on two years now and haven't yet had a single crash. Also we don't allow corporate advertising so you'll never see any banner ads here. We rely on the members for financial support on a yearly basis. The cost of actually operating the site is very minimal so the members don't really mind helping out with that.

We have a pretty good group here for technical support as well and some of the material presented here came directly from IA. Anyway, that's how that goes. Welcome aboard!

Yo-

[kidastra]

Try replacing the crush gaskets on the header to block.
[emoji41]

even if there is no exhaust leak? I covered the popping exhaust with a towel to look/feel for a leak, didn't feel anything and the pop had enough force to push my hand off.

here is a video of what it sounds like
[youtube][/youtube]

[kidastra]

last thing is this site the old intruderalert site?

This site was borne because of the old intruderalert site. They kept having problems with crashing. This site was created because of that particular issue. While we are not the original IA, most all the members here are from there, including myself. We're going on two years now and haven't yet had a single crash. Also we don't allow corporate advertising so you'll never see any banner ads here. We rely on the members for financial support on a yearly basis. The cost of actually operating the site is very minimal so the members don't really mind helping out with that.

We have a pretty good group here for technical support as well and some of the material presented here came directly from IA. Anyway, that's how that goes. Welcome aboard!

Yo-

I was a member of IA, was wondering why all the links were broken. Good to know the site was reborn

[kidastra]

Try replacing the crush gaskets on the header to block.
[emoji41]

I second this idea. I also would suggest you check the boot from the front carb to the jug. They're know to develop small rips/tears/holes which allow for air to be sucked in that will cause pops.

I'll change it if I must, but I'll check that boot also. Jug means the engine?

[kidastra]

Start by increasing your idle a bit and adjusting the A/F mixture. If that continues, you probably have an air leak somewhere.

The crush gaskets are a typical source of air leaks, especially if they weren't replaced when pipes were removed.

idle was increased after the video, air fuel has never been touched, so i'll check that as well when checking the other 2 suggestions

pipes were never removed since I owned this bike

[kidastra]

OK... now you're getting warmer. If your bike has aftermarket pipes, the A/F screws MUST be adjusted to compensate for the increased air flow. If you also have aftermarket air filters, like K&N, then they'll need even more adjusting.

From the factory, the carbs have plugs over the A/F screws. If they're still in place, then you'll likely see a vast improvement when you remove the plugs and adjust the screws.

Good to know, the bike does have aftermarket pipes, I bought the bike with them already on, rode it for a couple years with no popping anywhere (had the occasional backfire while riding)

I suspect an air leak more then a needle setting, but I will definitely check everything you guys have suggested, do you still thing the crush gasket should be checked?

[Lechy]

The 750-800's have an aggressive valve timing, the exhaust valve stays open for a short time on the induction stroke which sucks a little of the exhaust gas back into the cylinder. If there is a leak at the header connection raw cool air will be sucked through it into the exhaust system and will cause an ignition of the un-burned fuel. I suspect that the 1400 has the same cam timing.

The other suggestions are all valid and will need to be checked out also.

[emoji41]

[Lechy]

I don't have experience with the 1400 but I do know they have a de-compression system for starting, this needs to be checked and adjusted occasionally.
Could be giving you problems.
[emoji41]

[kidastra]

OK... now you're getting warmer. If your bike has aftermarket pipes, the A/F screws MUST be adjusted to compensate for the increased air flow. If you also have aftermarket air filters, like K&N, then they'll need even more adjusting.

From the factory, the carbs have plugs over the A/F screws. If they're still in place, then you'll likely see a vast improvement when you remove the plugs and adjust the screws.

Good to know, the bike does have aftermarket pipes, I bought the bike with them already on, rode it for a couple years with no popping anywhere (had the occasional backfire while riding)

I suspect an air leak more then a needle setting, but I will definitely check everything you guys have suggested, do you still thing the crush gasket should be checked?

Here's the thing with the crush gaskets. They are a one time use item. When the PO changed the pipes, its a 50-50 chance he replaced them. Some people look at them and think they look good enough to use again, or they don't know they're a one time deal. Since they cost next to nothing...about $20 for the pair, then it certainly won't hurt anything to swap them out.

You'll probably always have a certain amount of popping on the bike so long as you have aftermarket pipes. What I heard in your video is not "normal" with aftermarkets. You've got some other issue there. The problem is there are about 50 different reasons for the issue! OK, that was exaggeration, but you get the point. The easiest things to check have been discussed in this thread.

Let us know how it plays out.

will do, i'll check the crush gaskets last, when I had the bike 4 years ago, I was riding with no popping so i'll assume it is good for now

[kidastra]

I don't have experience with the 1400 but I do know they have a de-compression system for starting, this needs to be checked and adjusted occasionally.
Could be giving you problems.
[emoji41]

i'll start with the other items, then update the thread

[Lechy]

I'm slipping. First thing to do on Intruders is to clean up the battery connections and fit star washers under the bolts, also clean up the earth cable where it fits to the frame, check the earth cable, if it is stiff near the battery side make up a new one and replace it. A lot of problems that folks attribute to the fuel system are caused by dirty battery connections.
These old girls are powered from the battery not the alternator.
[emoji41]

[kidastra]

I'm slipping. First thing to do on Intruders is to clean up the battery connections and fit star washers under the bolts, also clean up the earth cable where it fits to the frame, check the earth cable, if it is stiff near the battery side make up a new one and replace it. A lot of problems that folks attribute to the fuel system are caused by dirty battery connections.
These old girls are powered from the battery not the alternator.
[emoji41]

even if its only popping on 1 cylinder?

[kidastra]

ok I checked out the boot from the carb to the cylinder, no signs of damage at all.
I did notice one bolt was a little loose, but not sure if that had an effect.

started her up and she purred, until she warmed up, then the popping started again.

I then tried the air fuel screw, turning it in might have fixed it... still monitoring

is turning in leaning the mixture or richening? I am trying to understand what is causing the popping on 1 cylinder

[kidastra]

this is the best it has run, about 5 minutes later it sounded like the first video.
[youtube][/youtube]

[kidastra]

so playing with the front carb air fuel screw seemed to work, 2.5 full turns right (in I assume) the popping stops completely,

If this fixed it I want to thank all of you for the help

also the a/f screw was already uncovered, so I assume it was adjusted when the pipes were put on.

[kidastra]

If you seated the screw all the way by going 2.5 turns clockwise, then you shut off the gas to that cylinder. You're running in one cylinder now. Bad idea.

Still felt exhaust pressure from both exhausts.
I'll check how many turns out I am now

[kidastra]

Seems like I am 1.4 turns out

[Blaine]

Seems like I am 1.4 turns out

Not enough.Your running lean.