Author Topic: 2014 uxv700i will not start  (Read 532 times)

300winchester

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2014 uxv700i will not start
« on: October 15, 2022, 07:58:02 PM »
Here is what I did
took compression, 90 psi, manual says 213
i have inspection covers off for valve adjustment and this is what I am seeing
when i turn crankshaft
exhaust valves open and close
intake valves open and close
then just a tad more turn and I hear a snap. clank and i can even feel the exhaust valves vibrate while this happens
I brought to TDC compression stroke , readjusted valves, compression still 90 ?
thanks all

CROSSBOLT

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Re: 2014 uxv700i will not start
« Reply #1 on: October 15, 2022, 08:05:00 PM »
90 sounds a little low. Either a valve not closing all the way or piston/rings. Can be valve timing out, also. That's why confirm betweem cam and crank positions.
Karl

Three motorcycles 1960-1977 (restored a 1955 BSA)
Agility 50
Yager 200i
Downtown 300i
Navy tech, Ships Engineer, pilot and aircraft mechanic

300winchester

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Re: 2014 uxv700i will not start
« Reply #2 on: October 16, 2022, 12:25:18 AM »
From some awesome help and replies from CROSSBOLT I think I may have found the issue, I hope. I took off the top valve cover and per Crossbolts recommendations I think I have comfirmed the timing has jumped
Tomorrow another day and will reset timing chain on sprocket and retake compression and more.
stay tuned for updates
Thanks all
This click in the exhaust valves is a decompression built in to this camshaft. it decreases compression on cold starts for easier starting.
MGM

CROSSBOLT

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Re: 2014 uxv700i will not start
« Reply #3 on: October 16, 2022, 12:31:39 AM »
From some awesome help and replies from CROSSBOLT I think I may have found the issue, I hope. I took off the top valve cover and per Crossbolts recommendations I think I have comfirmed the timing has jumped
Tomorrow another day and will reset timing chain on sprocket and retake compression and more.
stay tuned for updates
Thanks all
This click in the exhaust valves is a decompression built in to this camshaft. it decreases compression on cold starts for easier starting.
MGM
Aw, shucks! Bet you say that to all the girls! Har, har!

Yes, there is a compression release kinda similar to Briggs and Stratton that doesn't seem to work well, either!

Now, WHY would a timing chain jump time? While at it check your chain tensioner...
Karl

Three motorcycles 1960-1977 (restored a 1955 BSA)
Agility 50
Yager 200i
Downtown 300i
Navy tech, Ships Engineer, pilot and aircraft mechanic

airshot

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Re: 2014 uxv700i will not start
« Reply #4 on: October 16, 2022, 04:07:13 PM »
Any chance the flywheel key may have sheared?  Your issue description fits a sheared key in outboard motors !!!  Not uncommon to find.  Good luck and keep us posted..

CROSSBOLT

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Karl

Three motorcycles 1960-1977 (restored a 1955 BSA)
Agility 50
Yager 200i
Downtown 300i
Navy tech, Ships Engineer, pilot and aircraft mechanic

300winchester

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Re: 2014 uxv700i will not start
« Reply #6 on: October 17, 2022, 08:08:58 PM »
For all you following this post this is what I found.  While checking over and over and over again, with the timing mark on flywheel lined up I adjusted timing, no good,
so after watching a pencil go up and down while rotating flywheel to timing mark i noticed the piston was already heading back down by the time the timing mark arrived.  So I pulled the flywheel and sure enough (long story ) but someone other than me who replace side stator cover gasket did not tighten nut on side cover good. so it fell off and that what cause the flywheel to slide slightly off key and ruin the inside of flywheel taper.  it was ruined, by at least 1/2".  So, timing was correct but flywheel was the issue, ordered new flywheel, will put back together, reset timing , valve lash and see what happened.  With the decompression part on the exhaust valve cam Im not sure how you are ever suppose to read 213psi,  it releases pressure for starts.  Ill post again once i received flywheel and put back together. 
MGM



300winchester

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Re: 2014 uxv700i will not start
« Reply #7 on: October 17, 2022, 08:09:41 PM »
great call AIRSHOT

stuo

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Re: 2014 uxv700i will not start
« Reply #8 on: October 17, 2022, 09:02:19 PM »
I doubt that 213psi is a correct compression rating. If you divide 213 by 14.7, (the normal air pressure at sea level) you get a compression ratio of 14.5 to 1, which seems too high. A ratio of 10 to 1 is considered high compression but within reason, which would give a reading of 147psi. I'd like to know the compression reading you get after the repairs.
2009 GV 250

300winchester

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Re: 2014 uxv700i will not start
« Reply #9 on: October 17, 2022, 10:52:13 PM »
I'll for sure let you know Stuo
that darn decompression thingy is whats not allowing me to see true psi but when all back together I will post my findings
thanks all
MGM
I ordered just the defective piece of flywheel, my sprag clutch part of the flywheel was not damaged. 
31110-LKM8-900 from a great local dealer.

300winchester

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Re: 2014 uxv700i will not start
« Reply #10 on: October 17, 2022, 10:56:10 PM »


this kind of explains a decompression cam,  at slow loses compression to make it easier to start, once speed up no release.  pretty cool,

Stig / Major Tom

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Re: 2014 uxv700i will not start
« Reply #11 on: October 17, 2022, 11:30:44 PM »


this kind of explains a decompression cam,  at slow loses compression to make it easier to start, once speed up no release.  pretty cool,
The 155cc engine in my Piaggio Liberty has such a device. I wonder if is there to help the miserably small 6Ah battery get things going🙃
Stig
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And, I'm feeling a little peculiar.

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