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Hello all. Happy to be on this site. The information is priceless. Quick background on me, I have built hot rod cars from 1920's to 70's for many years.
I currently have a 1991 Yamaha Moto4 250 2wd quad. The bike is in great shape. I bought it from an older guy who used it around his farm until it decided to stop running. He figured it was an electronic issue since it was a "crank no start" situation. He replaced the original CDI with a cheap Chinese unit and a stator with a cheap amazon part. What was happening, as you started it, with the spark plug grounded, it would spark on the the push of the starter button - then no spark as it turned over - then spark when the button was released. When I got the bike, he did give me the oem cdi and stator.
Fast forwarding, I picked up a manual. I started to check all the electronic specs.
~The original stator, falls in spec per the troubleshooting methods as described by Yamaha. I swapped out the china stator for the original.
~The china cdi box was removed and i put the original cdi back in. What I discovered was the original cdi did not give off any spark. I picked up another original 'good used' cdi as I dont know if it is possible to test.
~new DK coil pack, spark plug and spark plug cover and swapped it in. ( I tested spark plug cover, the manual says it should be 10 ohms but the plug cover is showing 5 ohms. Not sure if this is vital issue)
Now I am getting spark consistently out of the plug, grounded to head/fins.
I have 2 china carbs. One that came on the bike and a 2nd new in box. Fuel is flowing from the tank to carb.
When I try to start, the bike just turns over. Fuel appears to be flowing from the carb (clear yellow fuel line), notably when I put my hand over the carb, I get fuel on my hand from the vacuum. Every now and again, it does burp or 'fire' a few quick cylinder cycles (like "3-4 fires in cylinder" (boom, boom, boom)). It burps back through the carb more than it does to try to start. I tried starting fluid, it does pop, but nothing consistent to want to run or even go vroom!.
I have checked the timing and it "appears" to be spot on. I even check to make sure piston is all the way up on the firing cycle. Without over thinking this, I did notice as the flywheel is at TDC, the cam gear was off a little to the right, not completely straight up and down to timing mark as per the manual. With all that I have done, I feel like the timing chain off, and timing is the main issue (replace timing chain), am I wrong?
I have adjusted the rockers per cold values in manual. I did a compression check and with the throttle closed, im getting 114 psi roughly. I did see some posts saying that the throttle should be open to get the correct value, Ill perform this and update my post.
Unfortunately, its still not starting/running.
I'm at a loss and about to replace the timing chain. I dont think it is a mechanical issue, but I need some fresh perspective....
Any help is greatly appreciated.
Hello im a newbie ive been looking around on the page for sometime but new to posting and not so good on typing lol but my question is, is there any other 50cc parts that will work on the "86" lt50 g? meaning any other CHEAPER parts like aftermarket or other 50cc cheaper parts ? Thanx in advace ,and if its not the right forum im sorry i just figured this is the one lol ps. I did a dumb mistake i put a screwdriver in the flywheel to try n remove it quickly and scratched the coil breaking a few wraps [email protected]#! Lol
I'm about to service my big bear and have a few questions,
1. Transfer case oil- I believe this is the same as the engine 10w40? How much do I need for the transfer and the engine?
2. Is there a link for the oil in the transfer case to back and forth between the transfer and engine?
3. diff oil- I'm looking at doing both best viscosity and how much will I Need?
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Hey all, just signed up. New to ATVs as well, just bought my first quad last week. 89 Yamaha Big Bear 350. Spent the last week or so ordering and installing some parts. Barely ran when I got it and now it does pretty well, still have some lean problems but Ill get to those. Waiting for my Clymer manual to come in so I can learn a bit more. Just downloaded a service manual from here so Im currently going through that till mine comes in.
Took apart the carb and cleaned and adjusted it a bit, runs waaaaay better now, just got back from a test drive. I can take off and idle now w/o feathering the throttle to keep going Always a plus.
Hi everyone in quad land. I have actually had my quad for a couple of years but decided to get on here and interact with other quad owners and chat it up a bit. I have really been a 3-wheeler guy back in my younger years (and currently have an 87 Honda 200x that I am restoring) but since 3-wheelers have gone bye-bye, I decided to get a nice quad. I have always been the type for something fast and I happened upon this new Honda TRX700xx that my local Honda place had that they were trying to move since it was an 08 model and they were coming into 2011. I was able to get it for half price. Now I know there are those die-hard Yamaha Raptor guys and others, but I really couldn't turn this one down for the price and I am really enjoying the torque, power, and smooth ride of this quad. Are there any central Arkansas quad owners out there?
Im the new guy. Im from Rogers Arkansas and i love riding:) found this board by accident but I LOVE it so far, IM looking for more people to ride with in Arkansas or Oklahoma (Little Sahara) or Missouri. Also just lookin for new friends to communicate with on the Forum:)
Anyways I have Pics of my Quad on my profile. Anyone that is close to my area or that just wants to talk drop me a message.
Thanks Blaze:cute: :tongue:
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