Dax Titan 50cc 4-stroke (R2?) won't idle (long post w/ pics)

texsc

New Member
Jul 6, 2008
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skip the first paragraph if you don't wanna read the background info about the wreck and get to the problem.

I've had the the kit installed and running for over 200 miles, but about two months ago I was going around a turn (a little too fast) went across some dirt and wiped out! So I got up and sat on the curb for a bit and my foot was *really* killing me (broke 4 bones :eek:). I managed to get the chain lined up even though the crash bent the left rack mount... the right one was OK due to my reinforcement I added. It cranked right back up and idled great and drove fine all the way home. The next day I had to go to my dad's where my tools were and it ran fine then also. I could not get around to messing with it for a while because of the pain/etc so it sat in the garage waiting.

This past week after it sat for two months I got the rack mount straightened and reinforced and tried to get it to run and it would not idle. It used to crank without even putting the choke on and idle smooth as butter. Now I have to adjust the throttle screw in so it was always pumping more gas just to get it to idle with the choke on and runs horribly almost stalling, or trying to engage the clutch(centrifugal auto) due to higher revs.

When I try to switch the choke off it revs really high then just dies quickly. I can crank it with the choke off and pump the throttle and get it to go but must keep the revs up or it will die. At speed it runs ok, not quite like it used to but OK...same avg speed(29-31 flat road). I tried to just run out the problems and rode it for ~50 miles on a long trip... But it still behaves the same at idle.

I've removed and fully cleaned the carb 3 times now
Tried cranking without the filter
And tried without the filter and muffler (in case of back pressure/etc)
Removed the plug it was black and looked like it was not firing to the tip but down into the plug near the insulator so I replaced it.
Greased the clutch bearings

After all this it still runs the same: OK at speed, will not properly idle

I pulled the valve cover to check the valve clearances but don't know what the specs are supposed to be...
What I measured was: Intake - 0.008
Exhaust - 0.016

Any help greatly appreciated...can't figure this one out!!



And because everyone (me included) likes pics, here ya go...
This is on my Forge Sawback 7xx Full-Suspension mountain bike!


Here you can see the left support for the rack is bent...

Closeup of bent rack mount
 
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paul

Well-Known Member
Dec 23, 2007
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Kalamazoo, MI
yes its eather that or something really simple like the fuel line has a kink in it. i know its a short line but i replaced mine for it had a small kink. hope you get it running right. i would also send an email to dax and maybe he has some ideas. i put over a 1,000 miles on mine and never had any problems
 

texsc

New Member
Jul 6, 2008
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I'll pull the carb again and check the float.... I did look at it briefly and didn't notice anything but you never know.

The fuel line seems to be fine, I *think* it's actually getting too much fuel so float may be the cause. I'll let you guys know what I find out
 

thatsdax

Member
Feb 22, 2008
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www.thatsdax.com
Oh my gosh !! You need to remove the carrier and pound out the Stainless brackets straight, Remove and replace the carriage bolts. You can get them at ACE, Lowes ect. And then re install. I hope you are doing well. Those brackets are Grade 5 and you bent them? Wow ! Watch those turns and gravel !! Yikes !! Not sure why a hard impact would change the engine run. Could be fuel feed, Carb issue, I am not sure. You may have impacted the carb in such a way that you have broken or factured one or more of the gaskets. Spray some carb cleaner in those areas while it is running and check for air leaks. Remove and reinstall the Carrier. Re align. Be careful and..... Enjoy the ride....
 

texsc

New Member
Jul 6, 2008
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@thatsdax: I checked the first time I ever touched it and it was 2 full turns, but how far it the air screw supposed to be turned out?

well I had already straightened and reinforced the carrier as I stated in the first post, those were just some old pics after the wreck... I took a new one today I'll post below but still need to do some aligning. The right bracket it sitting lower than the left so I need to change the bracket location on the swingarm to even them out.

This is weird...
I took apart the carb and carefully inspected the float and all seemed well. I even blew into the fuel feed and could not blow air through went the float needle was engaged so I don't think that was the problem.

Reading some others posts about idle issues and the gaskets, I checked all of them to verify alignment/etc. The gasket between the filter plastic and the carb didn't line up to well, so I trimmed it carefully and then took all the parts/pieces of the carb out and cleaned them ALL again.


Carefully put it back together (minus air filter) making sure to align the gaskets and it cranked right up with the choke like it used to. Soooo, I let it run for a min to warm up then slid the choke to open and it kept on going as it originally did when I got it. I picked up the rear end and revved it and ran great, and it didn't die when I left off the gas at all.

I noticed the air filter was oily/fuel soaked, probably from backfires, so I cleaned it with some K&N cleaner then just rinsed thoroughly with water. After this I went back to crank it again (still no air filter) and to my amazement it was back to running like crap again after sitting less than 15 minutes from the prior good run.

Any ideas?

reinforced carrier (still needs to be aligned)


float


choke side of carb


All carb parts removed...
 
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Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
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Float leaking/filling up?
I think when you crashed, you may have affected the operation of the float and it's sticking itermittantly.
 

thatsdax

Member
Feb 22, 2008
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www.thatsdax.com
Update to R3 mounts and a new carb. You may have cracked the Float or a seal somewhere. Also..Update your mounts to R3 so you can position your engine back and much lower. This will help a ton. Contact me for help. I will help you update. Let me know. Thanks..