Adjusted Valves runs and sounds poorly

[freebo86 291]

4 hours ago, retro said:

 

I have a hunch that the exhaust valve may be hanging open due to the automatic compression release sticking. Do you mind testing for that possibility by readjusting the exhaust valve lash to .015" temporarily?

 

EDIT: The comp release doesn't have to be stuck to hold the exhaust valve open when it should be closed... it could have a worn out exhaust lobe on the cam and/or a worn out lifter which could allow for a perfectly functional comp release to hold the exhaust valve open. Adjusting the exhaust lash to .015" (.38mm) would reveal any of those problems though.

yes I’ll give this a go tonight. So set the exhaust to .015, intake to .006 and let it warm up and then see if it starts? 

[Goober 1,555]

Ok thanks for catching me up. very good. So ignition is normal, it starts up easily with the choke, runs well, even after warmup. then while riding it dies suddenly and without getting hot or other symptoms?

Valve train noise since you fixed the muffler?
 

plug doesn’t look terrible sooty.

 

Not overheating. Fan kicks on? Were you riding it and fan kicked on or stationary?

 

does your choke cable stick at all? choke valve seems to be working. Lube the cable to be sure it’s free.

 

you have low compression while it’s warm and higher compression when cold?
 

I like Retro’s suggestion. 

Edited February 22, 2021 by Goober

[jdlmodelt 38]

On 2/3/2021 at 7:20 PM, freebo86 said:

Thats the issue. So many that I don’t even know where to begin, lol. Quite overwhelmed and frightened considering seems like the possibility is endless along with the money train that I can throw at it. 

Does this model have the fuel pump that ticks when its pumping? My fuel pump is fairly audible and It was a semi continuous to semi random ticking rythm.

13 minutes ago, Goober said:

Ok thanks for catching me up. very good. So ignition is normal, it starts up easily with the choke, runs well, even after warmup. then while riding it dies suddenly and without getting hot or other symptoms?

Valve train noise since you fixed the muffler?
 

plug doesn’t look terrible sooty.

 

Not overheating. Fan kicks on? Were you riding it and fan kicked on or stationary?

 

does your choke cable stick at all? choke valve seems to be working. Lube the cable to be sure it’s free.

 

you have low compression while it’s warm and higher compression when cold?
 

I like Retro’s suggestion. 

The decompression interfering while warm/hot makes sense with regards to the compression. The only other thing I can think of is do a top end overhaul. Sounds like you'll see things in there that you can't see right now. Mine had cupped rockers where they ride on the cam. Cam was fine. My top (intake) side of piston and cylinder were scored due to overheating or lack of lubrication. Now, new rockers, bored out 0.5mm and new Wiseco 10:1 piston and she runs.

[freebo86 291]

16 minutes ago, Goober said:

Ok thanks for catching me up. very good. So ignition is normal, it starts up easily with the choke, runs well, even after warmup. then while riding it dies suddenly and without getting hot or other symptoms?

It starts up easily when its COLD. Runs well (at times). Never dies on me while riding. Will keep running as long as there is gas and I don't turn it off.

Valve train noise since you fixed the muffler?
Nope, valve train noise seemed to happen more after I adjusted the valves.

 

plug doesn’t look terrible sooty.

 

Not overheating. Fan kicks on? Were you riding it and fan kicked on or stationary?

Fan has kicked on while riding, fan also will kick on if I'm stationary and letting the thing idle without riding during troubleshooting. 

 

does your choke cable stick at all? choke valve seems to be working. Lube the cable to be sure it’s free.

Choke pulls in and out smooothly. I looked at the plunger while out of the carb, can get it to move in out of the little housing.. unless its worn down or the seal on it is gone thats all I can confirm on the choke plunger. Cable moves freely i checked routing.

 

you have low compression while it’s warm and higher compression when cold?
You got it boss. Cold = ~75-80psi.

Warm 60-65psi.

 

I like Retro’s suggestion. 

 

Responses in bold for your reading pleasures.

[freebo86 291]

4 minutes ago, jdlmodelt said:

Does this model have the fuel pump that ticks when its pumping? My fuel pump is fairly audible and It was a semi continuous to semi random ticking rythm.

The decompression interfering while warm/hot makes sense with regards to the compression. The only other thing I can think of is do a top end overhaul. Sounds like you'll see things in there that you can't see right now. Mine had cupped rockers where they ride on the cam. Cam was fine. My top (intake) side of piston and cylinder were scored due to overheating or lack of lubrication. Now, new rockers, bored out 0.5mm and new Wiseco 10:1 piston and she runs.

 

No fuel pump on this ancient beast. Just a carb and gravity that feeds fuel down.

 

 

[freebo86 291]

Your vast knowledge of these machines is something.. can you tell me is there differences in carbs between a 350 vs. 450? Would jetting be the only difference?

 

Looking to see if I can get my hands on another carb locally to put in to test and see if the carb is in fact POS I have. I got a buddy that has a 350 hes willing to lend me to test out my theory.

[_Wilson_™ 6,566]

did you try shooting a small blast of starting fluid in the intake ..while the bike is hot and shut off ? just to find out if it fire off ? would give a clue the carb might indeed be the issue. 

Edited February 22, 2021 by _Wilson_™

[freebo86 291]

3 minutes ago, _Wilson_™ said:

did you try shooting a small blast of starting fluid in the intake ..while the bike is hot and shut off ? 

 

I did not. But I tried pouring about half a tea spoon of gas down the spark plug hole. No difference.

Edited February 22, 2021 by freebo86

[jdlmodelt 38]

The numbers you posted for compression are pretty low for hot or cold. The carburetor isn't making your compression go down when the engine is hot. There is something mechanical that causes your compression to drop when hot. It's either as someone else indicated, decompression mechanism holding the exhaust valve(s) open, or scoring on your cylinder wall and piston, or some other mechanical issue with your valves. At this point, you would spend less time if you just pulled the top end off unless you are able to determine the decompression mechanism is the culprit.

 

 

[_Wilson_™ 6,566]

17 minutes ago, freebo86 said:

 

I did not. But I tried pouring about half a tea spoon of gas down the spark plug hole. No difference.

 

thank you, and, you did the compression test with the throttle open ? I'm thinking like goober, on retros idea. 

[jdlmodelt 38]

the compression new on these is 181-210psi. I think you indicated you have from 60-80psi? 

 

[freebo86 291]

18 minutes ago, jdlmodelt said:

the compression new on these is 181-210psi. I think you indicated you have from 60-80psi? 

 

 

You got it pontiac.

33 minutes ago, _Wilson_™ said:

 

thank you, and, you did the compression test with the throttle open ? I'm thinking like goober, on retros idea. 

Yes, throttle wide open. I will give retros idea a go tonight.

 

So to be clear, set the exhaust valve to .015 and keep the intake at .006? Then start the bike let it warm up.. shut it off and try starting it again? To see if it actually goes this time?

[Fishfiles 20,145]

13 minutes ago, jdlmodelt said:

the compression new on these is 181-210psi. I think you indicated you have from 60-80psi? 

 

there are two compression readings , one with out decompression and one with , I believe that is why Retro asked him to adjust the exhaust valve setting 

[retro 4,048]

1 hour ago, freebo86 said:

So to be clear, set the exhaust valve to .015 and keep the intake at .006? Then start the bike let it warm up.. shut it off and try starting it again? To see if it actually goes this time?

 

Yup, take a cold compression test after you readjust the exhaust valve to .015" and before you start the motor. Start the motor and take it up to operating temp. Shut it down and take a quick comp test while its hot (take a pic of the spark plug too if ya can?) then attempt to restart the motor. Let us know what your findings are.

[retro 4,048]

2 hours ago, freebo86 said:

Your vast knowledge of these machines is something.. can you tell me is there differences in carbs between a 350 vs. 450? Would jetting be the only difference?

 

Looking to see if I can get my hands on another carb locally to put in to test and see if the carb is in fact POS I have. I got a buddy that has a 350 hes willing to lend me to test out my theory.

 

While 350 and 450 carbs are both 32mm, its probably not worth your time trying to swap them. Lets try to find some more cylinder pressure before going back into the carb.

[Goober 1,555]

I didn’t see where you posted year. 00-01 manual i have shows Keihin VE93A and Rancher VE94A. Very similar, but likely  not the issue.

 

Yup very low compression seems to be key concern. If I’m on the same page, your highest reading is at the low end of the Decompressor-affected standard

Edited February 22, 2021 by Goober

[Tim-ANC 202]

Some of his vids are titled 2004 450ES

[Tim-ANC 202]

A couple of sellers offering new cheap carbs with 90 day warranties. Sure, they are probably made it China but we installed one on my buddies 350 and works great so far. Might be good just to get for trouble shooting. Crosses to Honda PN 16100-HN0-672 

 

Caltric Carburetor Carb for Honda 16100-HN0-672 / TRX450FE TRX450FM Foreman | eBay I have had good luck with customer service, quality, and returns with Caltric.

 

Carburetor Carb for Honda 16100-HN0-672 / TRX450FE TRX450FM Foreman | eBay Don't know this seller.

[freebo86 291]

Here is compression, cold after setting the exhaust valve to .015

 

Even higher than before.. the bike is running to get it to temp. Will report back.

 

Edited February 22, 2021 by freebo86

[freebo86 291]

So 15-20min idle and a rip around the block. Compression is a bit higher than before but still lower than cold.

 

 

[retro 4,048]

37 minutes ago, freebo86 said:

Here is compression, cold after setting the exhaust valve to .015

 

Are you adjusting valves using metric feeler gauges (mm), or inch feeler gauges? Note that 0.015" = 0.381mm....

[freebo86 291]

2 minutes ago, retro said:

 

Are you adjusting valves using metric feeler gauges (mm), or inch feeler gauges? Note that 0.015" = 0.381mm....

Inch.

 

Edited February 23, 2021 by freebo86

[retro 4,048]

Thanks. Does the motor start while it is hot now?

[freebo86 291]

18 minutes ago, retro said:

Thanks. Does the motor start while it is hot now?

Yes it seems. But the engine is making quite the ticking/chattering noise. 

[retro 4,048]

Thanks for testing! You will need to replace the camshaft, both lifters, cam chain and the chain tensioner shoe to fix it. Before we go any further can you tell us how many hours/miles/kms are on it? Does the motor consume any oil over time...? Does it puff smoke on cold startup?