Yammie Brap 180

[.RJ]

if fuel is in the bowl, it will pull into the cylinder. did you measure the float height? and, if its overflowing out of the overflow its most certainly flooding into the cylinder.

take the carb off, take it apart again, and start over step by step - i assume you have a shop manual for this thing?

[V1GiLaNtE]

if fuel is in the bowl, it will pull into the cylinder.  did you measure the float height?  and, if its overflowing out of the overflow its most certainly flooding into the cylinder.  

take the carb off, take it apart again, and start over step by step - i assume you have a shop manual for this thing?

No shop manual. I've measured the float height both in mm and as most folks put it "level" with the gasket rim. Float height should be 20-22mm. If it's flooding into the cylinder why is the spark plug bone dry?

[.RJ]

If the bowl is full, what is stopping fuel from getting in?

Pull the carb off and break it down again. Make sure every jet/port/etc in there is clear and not blocked. Carbs are such simple things but so damn frustrating when you think its right but 1 small thing can render the motor dead. Sometimes I hate them.

[V1GiLaNtE]

If the bowl is full, what is stopping fuel from getting in?

Pull the carb off and break it down again.  Make sure every jet/port/etc in there is clear and not blocked.  Carbs are such simple things but so damn frustrating when you think its right but 1 small thing can render the motor dead.  Sometimes I hate them.

That's what I don't understand. The only thing I can think of is by not having the air filter on there is not enough vacuum to pull the fuel into the cylinder? Is that even a thing? There are no vacuum lines on the carb otherwise. 

When I pull it apart fuel goes everywhere from the bowl. I've double and triple checked the float needle port with compressed air to ensure that the needle is blocking the fuel flow off when closed. It is. That tells me that circuit is working. I think I've torn this carb apart 10 times. I went ahead and downloaded the manual for $15.

List of things to double check tonight:

- Ensure spark plug gap is .024-.028mm (Bike bandit lists gap as .032, but manual says the former range. NGK plug comes @ .032)
- Swap spark plug with newly gaped plug
- Ensure there is indeed spark
- Double check slide needle is on position #2 (I did a direct swap of c-clip from old to new)
- Double check air mixture screw is 1.5 turns out (again)
- Double check idle screw is .5 turns out (again)
- Double check float height it 20-22mm from gasket surface (again)

[Deceus]

You can put a grocery bag near the intake to make sure you have good vacuum. The carb should try to suck it in. The filter shouldn't affect vacuum all but a leak past or in the carb anywhere can. It can also be a thing if your valve timing is off by a good bit. Ask me how I know lol.

edit: TIL 2 strokes don't have valves so forget that part.

[V1GiLaNtE]

You can put a grocery bag near the intake to make sure you have good vacuum. The carb should try to suck it in. The filter shouldn't affect vacuum all but a leak past or in the carb anywhere can. It can also be a thing if your valve timing is off by a good bit. Ask me how I know lol.

edit: TIL 2 strokes don't have valves so forget that part.

Good tip. I've heard things like covering it with your hand too. However, when I started it on fluid it was just the airbox so I don't think it's a vacuum issue. 

Also, TIL there is a needle jet (#2) which the main jet feeds into and it is removable on these carbs.. Something I haven't removed and cleaned... Seems to be small number of things working against me. No wonder people want to burn down carburetor bikes/cars and collect the insurance money, because, ya know, fuel leaking onto a hot engine can cause a fire.. just sayin..

[.RJ]

Also, if the top of the carb has a rubber diaphragm, make sure its not torn. That will keep the slide from opening if its a CV style carb. but yeah, clean that main jet needle.

[V1GiLaNtE]

Also, if the top of the carb has a rubber diaphragm, make sure its not torn.  That will keep the slide from opening if its a CV style carb.  but yeah, clean that main jet needle.

It's a slide style carb so no diaphragm.

[rherold9]

Let's see if just having my annoying ass out there asking a million questions and trying things that have been already tried helps tonight. I'll be home to help after the gym bb . Gapping tool is in my black toolbox with yellow top.

[rherold9]

She lives. Time for many braps. Watch the whole clip





http://cloud.tapatalk.com/s/5b62468caa8c...558597.mp4

Sent from my Pixel using Tapatalk

[.RJ]

yasss!

[rherold9]

Here comes dat boi. Me feeling so good riding around and making braps!

http://cloud.tapatalk.com/s/5b625be6adab...739416.mp4

Sent from my Pixel using Tapatalk

[V1GiLaNtE]

Well she lives and is running. After running through the checklist Ryan came home and we started tackling electrical. Pulled the ignition coil, cleaned up the contacts, and got super confused with the multi-meter. The readings were all over the place. The ohm resistance was spot on for the spark plug cap. The ignition coil was another story. Was convinced I was going to have to buy an expensive ass "new used" part. After buttoning it back up it literally fired on the first kick. Unbelievable.

Ran it on the Deer park "aux" tank and it idled and ran!

Observations:

1) The idle screw barely makes much difference in the idle. Either it's high or it's not high and running
2) When we pulled it in, the carb overflow tube dumped a nice amount of gas on the ground
3) While the throttle and clutch needs to be adjusted, it has some serious hesitation/bogging at the low end on 1/4 throttle and then picks up with immense speed.

I think the float is still allowing too much fuel in which would explain the the overflow and the hesitation down low (too rich). Now that it is running I am going to swap in the old float and needle and see what happens.

Other essential things to do:
0) Seal inside of gas tank with POR-15
1) Adjust throttle
2) Adjust clutch
3) Change trans oil
4) Inspect and adjust drums
5) Grease rear wheel bearings
7) Bleed brakes (it takes a lot of braking power to slow her down)
8) Replace chain & sprocket

[.RJ]

what is wrong with the fuel tank?

DIY sealing it ALWAYS ends poorly....

[V1GiLaNtE]

what is wrong with the fuel tank?

DIY sealing it ALWAYS ends poorly....

It was quite rusty on the ridge that goes over the frame. The rest of the tank was very clean. Soaked it in apple cider vinegar and cleaned it up. Now it's clean (with pitting), but it needs to be sealed to prevent further rust.

Interesting, everything I have read about the POR-15 Tank sealer works really well. This isn't a daily street bike, nor do I think I'll keep it for years to come. It is 20 years old at this point.

[.RJ]

If its clean, keep fuel in it and leave it be. Seriously. I've seen enough old tanks that have been sealed and it never, ever, ever ends well long term - the stuff doesnt adhere to the surface properly and flakes off.

It can be sealed, but you really need to dip the whole tank which will destroy the paint - the only take that's held up well long term was done this way.

[Deceus]

POR-15 is some good stuff. I have also heard nothing but good things about their tank sealer from the muscle car guys. I never used it myself since my gas tank was cheap enough to buy and not risk it. You can practically hammer on the stuff if it's applied right which is easier said than done.

[V1GiLaNtE]

If its clean, keep fuel in it and leave it be.  Seriously.  I've seen enough old tanks that have been sealed and it never, ever, ever ends well long term - the stuff doesnt adhere to the surface properly and flakes off.

It can be sealed, but you really need to dip the whole tank which will destroy the paint - the only take that's held up well long term was done this way.

It's displayed a bunch of pin hole leaks after soaking it in ACV so I'm going to go ahead a seal it. IF it becomes a problem long term I'll probably source a completely different tank. I'm not dumping $100+ into a "new used" tank on ebay for a free bike.

[V1GiLaNtE]

Ordered an oil seal for the kick-start since it was leaking from there as well as an OEM blue rear fender. Updated cost and list on main page.

Items to tackle this weekend:

1) Check plug condition to determine lean vs rich mixture
2) Adjust idle/mixture
3) Bleed front brake and replace fluid
4) Inspect/clean/adjust rear drum brake
5) Repack rear wheel bearings
6) Clean/lube/adjust chain
7) Replace misc. missing nuts/bolts
8) Install airbox
9) Figure out some sort of side panel replacement

[.RJ]

If the bike is stock air filter/pipe/jets, you dont really need to check plug condition - but if it has changed and you dont have a known combo of filter/pipe/jets to work from you'll need a stack of plugs to read from. Glad its coming together!