BRed 2011 MUV700 - Start Troubles [SOLVED]

[fmjnax]

2011 Big Red MUV700. I picked it up as a project. Rebuilt the engine (among other things). Previous owner had put in a brand new battery 2 days before I got it because it wouldn't start (though it wasn't quite the right battery: a Duralast ETX14L 220cca). I put a new starter in it and all was good... at first.

Over the past 2 months, it has started to have the same symptoms that led the previous owner to buy a new battery. Slow starting and sometimes not enough torque to turn the engine over at all. If I pull the plug, it will turn the engine over-and-over until the battery dies. Happens even if I jump the solenoid and even if I apply 12v directly to the post and ground the case. I didn't think the starter would have given out in 2 short months but this past week I put yet another new starter in it and also purchased a proper YTX14BS 235cca. I also purchased a new solenoid relay but it hasn't arrived yet. With the new battery and starter, it fires up again. However, sometimes it still hangs up and won't turn the engine over unless I hold the key. Battery is fully charged. Maybe the solenoid will fix it, but I'm not too hopeful.

Once I do get it started, the machine runs beautifully. The engine is basically new and has STRONG compression so I expect it to be tight, but can there be too much compression to keep the starter from turning it over? What other things could cause this and/or what should I check for?

 

[Admin]

 

[DG Rider]

2011 Big Red MUV700. I picked it up as a project. Rebuilt the engine (among other things). Previous owner had put in a brand new battery 2 days before I got it because it wouldn't start (though it wasn't quite the right battery: a Duralast ETX14L 220cca). I put a new starter in it and all was good... at first.

Over the past 2 months, it has started to have the same symptoms that led the previous owner to buy a new battery. Slow starting and sometimes not enough torque to turn the engine over at all. If I pull the plug, it will turn the engine over-and-over until the battery dies. Happens even if I jump the solenoid and even if I apply 12v directly to the post and ground the case. I didn't think the starter would have given out in 2 short months but this past week I put yet another new starter in it and also purchased a proper YTX14BS 235cca. I also purchased a new solenoid relay but it hasn't arrived yet. With the new battery and starter, it fires up again. However, sometimes it still hangs up and won't turn the engine over unless I hold the key. Battery is fully charged. Maybe the solenoid will fix it, but I'm not too hopeful.

Once I do get it started, the machine runs beautifully. The engine is basically new and has STRONG compression so I expect it to be tight, but can there be too much compression to keep the starter from turning it over? What other things could cause this and/or what should I check for?

Check the actual compression. There is supposed to be a decompression device on the cam just to make life easier on the starter. The spec is 80 Psi for a stock engine.

 

[fmjnax]

Ah, thanks DG Rider. I bet that is what is wrong. I can't even take a compression reading because the starter can't turn it over reliably with the plug (or gauge, in this case) in. I'm going to start tearing down the top-end and see what I can find. I have a manual but it's not totally clear what I'm checking for with the decompressor. Any suggestions?

Also, could this happen if I was 180 degrees off (meaning I lined up the indicator on the exhaust stroke instead of the compression stroke)?

 

[fmjnax]

I went ahead and ordered a new cam before ripping in to the top-end. Part was cheap enough and this machine had a ROUGH past so why not. Received it today and went to work. Got the new cam installed without any issues. Set valve clearances to spec. Bolted it back up enough to give it a test. Threw in a brand new starter and brand new battery and turned the key... exact same issue. It will not turn completely over. WAY too much compression. 130 psi, to be exact!!

The internals, as far as I could see, all look good (as they should, being just rebuilt). No troubles turning the crankshaft by hand while aligning TDC. I am pretty sure I was on TDC at the compression stroke as both cam lobes were downwards and both rocker arms had up and down play once bolted up. Maybe my timing was off a tooth, but it was lined up as it should have. As far as I can tell, it was all by the book.

Any other suggestions?

 

[fmjnax]

Issue resolved (for now).

After confirming all of the electrical components were good, I took the top-end back apart. I broke down the valve assembly and made sure it was all in spec. I then cleaned all (98% of it, anyway) of the carbon up.

On that teardown, I took a look at the timing from various angles and really scrutinized it. It looked slightly off so I realigned that. It was 2 teeth off (retarded, I think it was).

Bolted it all back up and turned the key. Fired right up. I'm pretty sure it was the timing being off, but the valve cleanup and re-adjustment certainly could have helped.

I need to top off the oil and put new coolant in it and then I'll make sure it wasn't a fluke start, but I'm optimistic that it's all good to go now.

 

[Hawkeye01]

Interesting updates as I've got a 2013 that same some ugly gremlins that I can't seem to track down around MUV700 not starting. As the previous person stated my MUV is having similar issues. Sometimes I jump in turn it over and the machine starts without issue. Then other times with a fully charged battery, good solenoid, I have three starters (all good) the machine will make a single click and not turn over.

I've checked volts, ohms, amps, grounds, all wires from starter to solenoid and batter to ground and all are sound and complete to spec. I did sand every ground point, replaced fuses, cleaned diod's etc and still sometimes the machine does great starts fine and then sometimes it just clicks a single time and nothing. If you turn it off and try again the same thing occurs.

I've replaced the ignition switch with a honda OEM I'm at a loss on how to resolve to ensure it turns over every time not just some times lol.

 

[Hawkeye01]

Interesting updates as I've got a 2013 that same some ugly gremlins that I can't seem to track down around MUV700 not starting. As the previous person stated my MUV is having similar issues. Sometimes I jump in turn it over and the machine starts without issue. Then other times with a fully charged battery, good solenoid, I have three starters (all good) the machine will make a single click and not turn over.

I've checked volts, ohms, amps, grounds, all wires from starter to solenoid and batter to ground and all are sound and complete to spec. I did sand every ground point, replaced fuses, cleaned diod's etc and still sometimes the machine does great starts fine and then sometimes it just clicks a single time and nothing. If you turn it off and try again the same thing occurs.

I've replaced the ignition switch with a honda OEM I'm at a loss on how to resolve to ensure it turns over every time not just some times lol.

Did you ever figure out what was wrong with your MUV700? Mine does the exact same thing sometimes starts with no issues other times same as yours a single click and done...like you i've chased and replaced battery, solenoid, both cables to battery / starter, new starter relay etc and still same symptoms.