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Similar Forum Topics
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By Red_Dragon
Hey, I've been wanting to know if any mechanic would like to help me with my Custom quad frames from welding and parts list
Let me know by replying to this message. thank you!
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By h1000101b
STREET LEGAL - ONE OF A KIND HARLEY DAVIDSON 4-WHEELER $9,500 OBO Sporster 883 bored to 1200cc built into a Street Legal Licensed and Insured 4-Wheeler. It has 400ex front end, 250r Rear end. All chromed out with new black gloss paint. I have a $500 Dakota Digital Speedometer to go with it (needs installed). I also have an extra rear gear and extra set of off-road mud tires and rims. Brakes need to be adjusted, and there's a few other touch ups that will place it into show quality. I haven't started it in a while. Ran Great last run. This bike has over $20k invested in work and time. It will go about 120 mph or more. With the other gear it will go about 60 mph. It rides great on and off road. It brings trophies and turns heads at shows. Shoot me a message or offer if interested. (May entertain trades). I will entertain any offers. This is your only chance to own a Street Legal 4 wheeler. Currently titles and registered in KY.
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By SnowmanTX
Hello!
First time poster here, looking for help. This will be long, but I want to give you the whole story. I'm very confused because I am a fairly experienced mechanic but must be missing something. A friend who is not mechanical brought me a 2003 Eiger 400 automatic that didn't run. A quick inspection revealed that the motor was seized. I pulled the top end and found the cylinder and piston rings were rusted together from the machine having been submerged at some point and then left to sit for several years.
I put in a new piston and cylinder and checked the valve lash. Compression test today was 150 psi. Replaced the corroded vacuum petcock with a Yamaha petcock, cleaned the fuel tank out, and replaced all the fuel lines. Replaced the badly corroded carburetor with an Amazon aftermarket model (with good reviews) and it wouldn't start. Found that there was no spark so I substituted an Amazon 4-pin CDI box and found that I now have good spark. It still wouldn't start so I used a little starting fluid and it fired right up for about 3 seconds.
Now, after cleaning and checking out the new carburetor, I have found that when it cranks and fires, the engine actually kicks backwards momentarily and then resumes cranking. It is acting like the spark is way advanced and it is firing before TDC. I know that it is turning backwards momentarily because I still have the recoil off and I can see the starter cup rotating and then literally stopping momentarily when it fires. I've had the flywheel off to check the magnets and the woodruff key. The flywheel does not have the exposed magnets, but the fully enclosed magnets like the replacement RMStator flywheel. The woodruff key was in perfect condition. The pickup coil resistance test was good.
Since it seems like a timing issue, I pulled the cylinder head off again and double-checked the timing. It did appear that the timing marks were off by one tooth, so I corrected that and thought that I had found the problem. Unfortunately, it still does the same thing...It will crank just fine, but won’t start, and kicks backwards when it fires whether I use starting fluid or not.
Since the timing is not adjustable on this machine, I’m wondering if the factory CDI circuitry incorporates any type of variable timing feature that is dependent on RPM? That is about the only thing I can think of.
I've read other threads that discuss this "kickback" symptom and the usual culprits are weak battery or a too lean condition causing preignition. I've installed (and charged) a new battery and triple-checked both carburetors...the original one that I completely cleaned, and the Amazon replacement. Same response with both carbs, which leads me back to questioning the CDI.
Any body else run into this?
Thank in advance for your help.
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By 92BayouB
Hey there all,
First off thanks for the board. My Bayou 220 has survived 3 teenagers and is on its 4th now. Up until recently it has been a virtual tank....until I decided to fix it;)
Noticed some smoking from the engine block (not exhaust) so figured it was time for a quick top end rebuild. Now that I have it all back together, it fails to start. I've pulled the starter rope until my arm is tired.
So I will be as detailed as possible and hopefully get some help.
Completed:
-New Head gasket
-New Valve seals
-New piston (standard)
-New rings (standard)
-All new seals
-Cleaned up head and valves (didn't do any resurfacing, as it all cleaned up pretty easy)
-All torqued to spec
-Piston ring gaps all checked out
-Valve clearances (Intake: .18mm, Exhaust .20mm). Not too tight, not too loose.
Pros:
-Engine IS making decent compression
-DO have spark
-Will fire for a split second if I drop some gas in the spark plug hole and pull start. Will NOT from carb and or intake valve.
Timing:
So I followed the guide of: TDC
-Flywheel aligns on the “T” mark on the engine site hole
-Cam gear mark aligned with the cover mark
Seeing as this is my first time doing a top end rebuild on an ATV. Here are my questions and concerns:
-I didn't realize (dummy me) that there are 2 TDC's. 1- Compression, 1-Exhaust.
How do I know if I'm on the right one?
-Does the cam need to be aligned a certain way when put back in? I just aligned the cam gear dimple with the cam and put it in. No alignment.
Thanks ahead of time. I feel like I'm 90% there, but I'm missing an important step for completion.
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