Carb problems, scooter boggs By rsw1158 (Read 2,953 times)

[Alleyoop]

Bummer on the broken stud, Remember anything on the motor just nice and snug do not crank on any bolts going into the motor and or case.

Also to check if your ENRICHER is feeding it extra fuel just take it off and lay it on it side and cover the hole with your thumb and hold it there and start the motor keep your thumb on the hole for at least 3-4 minutes. as your letting it idle watch the ENRICHER and see if the gold cylinder EXTENDS out about 3/16-1/4 of an inch after 3-4 minutes if it does it is working.
Alleyoop

[Bashan]

Wow, good eye Alley, I thought that was a cap and a plug..... I need to pay closer attention. What do you think Alley, too much air? I don't THINK it's the coil but it happens. And 250....yeah, you have to get the CDI secured and it never hurts to have a few spare parts sitting around. That's one thing about this field, you don't have to break the bank to work on them, it's relatively inexpensive. Rich

[Alleyoop]

Well if it is MISSING then yea I would suspect the CDI and or coil, but he says it is BOGGING, so it air and fuel problem at the moment.
Alleyoop

[roketa250]

Agreed with your thoughts alley! Tomorrow I tackle the broken bolt and then onto swapping out the fuel pump. That won't be too much! It will be Wed when I get a chance to test those reworks.... Wish me luck!

[roketa250]

See if you can wrap your head around this one.... I attempted and failed at a bolt extraction. It was my first go at it and I really didn't know what I was doing. I watched a youtube video... Does that count? Now I'm left to deal with a broken tip of a hardened screw extractor in the hole. I've unsuccessfully tried to drill that out and no luck! Now I'm wondering what my next step is. I was thinking I could do all this off of the bike much easier but removing what I think to be the head isn't as easy as I thought.  I remember the chain actually runs into there and I don't know much about removing that and putting it back on. So I'm at a cross roads so to speak! I'm not sure what my next move should be but I have an idea to put the intake back on with a good bolt on one side and jb weld the other side. Think that might work? What's an alternate idea? Help! Please!

[Alleyoop]

What I try is to cut a slit in that piece with a dremel tool then heat up the side of the intake by the bolt and try and unscrew it out.
Alleyoop

[Bashan]

The JB won't stand up to those temperatures, I've tried it. It says on the spec sheet that it will but it gets crumbly over time. Alley has a great idea there, I never thought of that.

[roketa250]

This just keeps getting better and better. Quite an undertaking that's for sure! I need all the help/pictures/docs that you can spare on removing the engine completely from this scooter since I've come to the decision while failing to remove the bolt that broke in the head I'm just going to replace the entire head. Stupid me didn't realize there would be studs coming from the engine not bolts holding the head down. Duh! I should've known better. But it's a learning experience! I'm guessing it's as easy from where I'm at now all I have left is to pull the exhaust off and remove the swing arm. The wheel and once that happens the engine will slide back and I'll be able to remove the head or put the entire engine on the bench for that matter? Thanks and here are some pics on where I'm at currently...

[roketa250]

Just wanting to make sure I'm going in the right direction with the part. Found this one on eBay...
www.ebay.com/itm/291042567170?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Of if there is another website that is affordable and has oem replacement parts. Once again I have the 257cc Lanai horizontal yamaha clone engine. Thanks!

[roketa250]

Needing some direction please!!! Thanks!

[Bashan]

OK, I threw the chicken and Jack should appear within the next 12 hours.....buuuk....

OK, I've never did a Linhai horizontal. I've taken them out to dinner but things just didn't work out. Spent a damn fortune at Chiles too. If it hadn't been for the coupon, I would have complained more than I did!

All of these Chinese bikes have similar motor mounts, very close to the GY6 silentbloc swing mount. It's a double axis that allows the engine to move horizontally back and forth to absorb thrust forces. They all have the main engine bolt that needs to come out. To do that you will have to do the following:

#1: Get the head and cylinder back down so you don't damage the dowels or the piston. Try to secure it on a couple of the dowels after you get back down on there with bolts.
#2: Remove the exhaust, swing arm, rear wheel, everything but one of the shocks. You want something hold it up. Get a screw jack or other lifting device up under the pan of the engine, crank it up enough to take the pressure off of the shock.
#3: Take the engine bolt out, the engine will have to be weightless on the stand. Take the shock off. Lower the engine down and if you have some help you can probably drag it out the back.

I get a heavy scooter up in the air on my Harbor Freight lift, put a 4X4 across a couple jackstands, and lower the bike down on the 4X4. It lifts it up in the air, then I pull the engine out. You MUST secure the handle bars and make sure the bike is stable on the front wheel only or it will fall off of the lift. Or so Alley tells me.... I've never did that.  Rich

[JR]

OK I'm late to the party but it's simple get the engine/drive train out of the scooter. Take pics or label parts, wires, plugs if necessary. Once you get it out this engine will come apart easily. In the manuals here go to the Yamaha section and fine the YP250 Majesty Service manual, it has a complete engine breakdown.

Now one tip to know quickly, if you are going to replace the piston rings which I would do since I had it tore apart you MUST measure the piston first. Why? This engine can come in 3 different piston sizes 68, 69 and 70mm, the most common being the 69mm. Also even if you don't replace the rings you'll need to replace the bottom head cylinder gasket. Looks like this engine has been treated pretty rough?

JR

[roketa250]

Actually I'm not really sure what I'm looking at JR.... I'm going to post some pics once I get it apart and let you tell me. Question? Once I pull the head do I have to replace the head gasket? Also there is a lot of build up on the piston head and the valves. Anyway to clean this? ... Most importantly to know I've completely ruined the head. I was checking locally to get it fixed and there is no way it will be cheaper than just replacing it! With that being said I've got to make sure that all parts are installed in the head, As I know nothing about that... Plus I'm thinking are the valves going to be in the same place as mine i.e., one up one down... Does that make sense? I guess what I'm getting at is timing... As if you can't tell I'm kinda lost. I don't even know if what I'm saying makes sense! Feedback wanted! Thanks!

[Bashan]

Yes, you MUST put a new head gasket on! The old one, even if metal, distorts and will never be usable under those kinds of titanic forces again. If it was me I'd buy a head ready to go, valves are installed and you don't have to mess with anything, bolt it on. On a GY6 they're about $60.00, on a 250 I'm guessing $100.00. How much are you going to save if you have to buy a spring compressor? I understand the concept, I don't need to revisit the learning experience. I also don't need to ruin my afternoon trying to get springs compressed and insert the retainers. JMO, Rich

[roketa250]

Good opinion! In the range from $140 - $150 believe it or not. I'm seriously thinking of skipping eBay and spending the extra $10 and going with ScrappyDog. I can pick up the phone and call them if I have a question for that matter... Or just refer back to here. Plus I'm for the business owner before the online retailer! Here is what I need.... it's a little down the page under VOG cylinder head complete.
www.scrappydogscooters.com/LH170MN_Linhai_257___275.html