Misterclean

4 hours ago, 56Sierra said:

Fuel boils because of heat and reduced ambient pressure.   If his tank wasn't venting properly the fuel may boil.  The fuel pump, if there is one would have increased the pressure enough for the fuel to remain below the boiling point.  Shut the engine down, the pressure drops and vapor lock occurs.  Picture opening a soda bottle.  The CO2 comes out of solution or a diver accending too quickly and nitrogen boiling if his/her blood.

 But, it started when primed and ran good. That alone eliminates your theory. 

Let's not make this difficult. The mower started when hot with starting fluid and ran fine correct? This says ot was mot getting fuel correct? Unless there is more information that we don't know, them the problem is fuel delivery.  When the fuel boils it can't pump or even gravity feed thru the filter. The fuel must be boiling. Yes, even if it didn't do this when new. It doesnt.matter why.......it just does. You have cleaned the cooling fins so the only thing left to do in to insulate every fuel component you can between the fuel tank to the intake manifold.  This is an air cooled machine and they can get very hot .........Too hot for some fuels. This may be a symptom that isn't repairable but it's worth a try.

That is loose but it won't help your starting problem.  Your problem is fuel starvation from overheating. 

This thread had convicted me to lower my sodium intake. Reading online about salt substitutes I learned tha MSG has an incorrect bias that we have been taught for decades. I learned that a small percentage of people really have an allergy to it. If one uses it wisely there is almost no chance of any health concerns. The article went on to say that it is wise to eat carbs or protein at the same time to be safe. I'm doing this now.......Just started about a week ago. 

2 hours ago, slowindown said:

I cleaned the fins really good yesterday when the shroud was off and they weren’t very dirty at all. I can wrap the lines. I wonder why is it doing it and why it has gotten worse. 

Fuel has different blends for different time of the year which can lower the boiling points. Another thing.......an older engine runs hotter than a new engine. The cooling fan blades may be worn after a thousand hours of use. Higher octane fuel runs much cooler than low octane. Reduce the engine speed 50 rpms. Thin oil cools better than thick oil. Just a few ideas and facts. 

4 hours ago, shadetree said:

he's not going anywhere..unless his wife has him arrested for breaking her trx300fw ?..lol. it's all good...offer him a 30 pack..bet he'll reconsider !..rofl,

I could hand deliver the 30 pack in about 5 hours.......hmmmmmm?

Wow Fish, I just got caught up on this thread! I'm very sad to hear about you're stroke but very happy it was a 1. I will miss you and your great humor and perspective on things. I understand all aspects of the political and religious subject. I am a conservative Christian and a conservative on politics. A friend of mine that had a bar said I shouldn't talk religion or politics in his bar forty years ago. LOL I rubbed me wrong at the time but as I grew older I see the wisdom. It is a proven fact that the things that are most important to us are also the most volatile. I personally wish you would reconsider your decision ......at least stay here as a contributor. I would like to confess to everyone that I took a long vacation from this forum because of the Covid subject. Frankly it was hyperbolic in some ways because many if not all of the extreme predictions just didn't happen. I got angry but came back. I would probably leave again if something similar happened again. Fish, again, I really like your contributions ect.......please stay, please. sniff sniff

5 hours ago, texas123 said:

Anyone have any experience with the Toro Aluminum decked mowers? My Snapper 21" is over 12 years old and still works great with the 6.75 B&S engine, but last year I installed a 1 size smaller belt and damaged the driveline by putting too much tension on the levers and such. Parts would be almost $150, which is fine, but I parked it outside one year & a lot of the bolts have corroded to the point of sockets not fitting properly and I don't think it would go back together without a tap & dye set. It's $500 at HD, but it's a 22" with a 7.25 B&S engine.

The aluminum deck is a good idea but the aluminum wears out at the height adjuster making them jump out of the notch. Toro came up with a shim to slip in between but it was just an after thought. They are a little brittle and the steel bolts like to break off in the aluminum threads.

This is good news because it says there is a fuel problem. The fuel is probably boiling in the lines  and/or pump. Wrap the fuel lines with insulation and make sure the cooling fins are as clean as possible.

22 hours ago, slowindown said:

The dealer (local co-op) didn't have the gaskets (surprise).  So I ordered some and an oem fuel pump, just in case from amazon.  Should be in by the end of next week - apparently 2-day prime shipping is a thing of the past for where I live...

According to your diagnostics the fuel pump will not repair the problem because you said starting fluid doesn't help. I just don't want you to waste money. Please read my suggestions from a few days ago.......this procedure should narrow it down to spark, fuel or compression.

14 hours ago, slowindown said:

As I recall, Used to I could let it idle a bit and it would restart. I don’t think it will now. But I’m not 100% sure. I don’t usually turn it off unless I’m taking a break for awhile. I’ll test that this weekend.  
 

And Wilson yes, it seems to be a bit worse this year. 

If it runs fine until you shut it off and won't hit with starting fluid it could be flooding after you turn it off. There's a small chance that the coil super heats and quits firing or the valves that were on the edge of too tight get tight during the super heating of the engine. Engines will super heat if turned off after work on a hot day. I always let mine cool down at idle for 5 or 10 minutes. I usually blow or trim during the cool down period. It boils down to this.......you need to be prepared to diagnose your problem when it happens. Mow for an hour, kill it, wait a few minutes, verify that it will not start, spray staring fluid, if it doesn't start check for spark, if it  sparks then look for wet spark plugs (checking for flooding) . If that fails then quickly remove the blower housing and spin the flywheel backwards by hand. It should bounce sharply against the compression stroke. This method is the only way to check for true compression because it approaches the compression stroke from the opposite side of the cam shaft lobe where there is no compression release function.

14 hours ago, LedFTed said:

708cc, is from china, (i didnt know that, at the time)  i already had to adjust the valves once. its overdue. may have starter issues also. the hot going to the starter looks burnt. it acted up today, i could hear it popping inside of the house. it quit before the time i got out of the house, wouldnt start back up. ya just gotta love china, dont ya.. 😬😬😬

Disabled compression release can burn up a starter, solenoid and wires. It''s very hard on the battery too.

Your can also try to clean the cooling fins and maybe slow the engine speed down 50 RPM's. Overheating causes the fuel to boil. Wrapping insulation on the fuel hoes helps too.

On 7/5/2021 at 12:51 AM, LedFTed said:

the 1st pic. is not what i wanted to post. the 2nd is... i intend to install this on the ex-mark zero turn. its out of warranty,  an i have been through plenty of solenoids with this creature. when its hot, is the worst. wont start, have to get a charger. so i got a boost to the battery an now the battery will turn the starter, to fire the motor.

i ave already tested this, with a jumper start button, just hook up 2 wires, one goes to the battery, the other goes to the solenoid. gives extra strength from the battery, more voltage, or current. i have always jumped battery voltage to the plus terminal on the solenoid, and didnt know any other way. till of late. i was afraid to use my push button  jumper, across the battery terminals at the top of the solenoid.

Check your valve lash. If it is too large it disables the automatic compression release causing problems like you mentioned.

I'm exhausted! I just read the whole thing and was hoping for a happy ending........now I'm frustr

ated! LOL

12 hours ago, Honda 400X said:

No idea man.. all i know is i put a 2005 400ex engine in a 86 350x frame and seems like it was under geared.. when i was on 5th topping out on the road for a long period of time gunning the throttle it would starve eventually but normal riding in the trail it road perfectly fine.. this will only happen at wide open throttle in the street once it hit max mph and about 2 miles later..I would know it will starve because the second it would act up i shut the fuel valve off and stop the bike I would drain the carb and nothing will drain out..

That's new information for me. Wide open throttle for two miles! LOL That's hard on an engine! Perhaps the fuel was boiling because of the excessive heat built up in the fuel hose. If you have an inline fuel filter then remove it and just rely on the filter built into the petcock. Fuel does funny things when hot and gravity fed thru a filter media. Also re route and/or insulate the fuel hose. Hope this helps.

28 minutes ago, Honda 400X said:

So I already figured it out.. believe it or not it was gearing.. i have a 05 400ex motor in a 350x frame. I went to a 36 in the rear because my bike on 5th was screaming like it wanted to blow up and felt i needed to shift to 6th which there isn’t..  now it rides awesome and no more running out of fuel because i was over reving.. 350x frame is much lighter more aerodynamic and just 3 wheels on the ground.. i had checked all fuel flows i swapped petcocks, fuel lines, fuel cap and even carb and did nothing.. thanks for replying!👍🏻👍🏻

Ok but it does not sound logical to me. I'm 62 now and have played with gearing (for fun) for at least 35 years now and have never experienced anything like this. I've geared dirt bikes so tall that they wouldn't top out in high gear. 105 mph on my YZ 250 is a fairly recent example. An old 1978 RM 400 went so fast fast that the unbalanced front tire was literally hopping off the pavement. 

If its a fuel flow problem then I would do a flow test at the fuel hose where it connects to the carb nipple and another test out the bowl drain valve. A clogged bowl vent will do this as well. If the valves are too tight it will have these same symptoms. Hope this helps.

On 6/6/2021 at 10:03 AM, retro said:

By the way, you can renew a wet angle sensor by soaking it in 91% rubbing alcohol, then dry the alcohol out for a couple hours over some heat. Alcohol flushes renew many old and failing angle sensors too. 🙂

 

When I worked off shore in the olden days we could bring capacitors back to life by submerging them in Naptha overnight. I tried this procedure on an old air cooled yz 250 years ago. Didn't have naptha so I used gas.....it worked!

Concerning the break in procedure.........if it were an OEM top end I would say just run it.........perhaps a little easy on the first cut tho. Since it's aftermarket it's impossible to say because you didn't measure the clearances.....or didn't mention it. Because it's aftermarket, play it safe and do heat cycles and easy cuts etc. for a tank of gas. 38 years doing this and a few years before that on dirt bikes for me.

The first picture in the last post has shiny yellow fuel hose. Chinese hose is shiny and will fail very quickly. Tygon is the only hose I've used professionally. Looks good otherwise!!!!

I've been working on these things for 38 years. I must say those are some odd symptoms. Perhaps its flooding when not running? If it's tight valves I would suspect it would run poorly when hot. Best thing is to check spark when this happens and work down from there. Could adjust valves to be sure. I very curious myself. Please keep us posted.

2 hours ago, sled_22 said:

Yup, mixing oil is simple math. 128 oz per gallon so take 128 divided by mix ratio.

50:1 = 128/50 = 2.56oz oil per gal.

45:1 = 128/45 = 2.8oz oil per gal.

40:1 = 128/40 = 3.2oz oil per gal.

32:1 = 128/32 = 4oz per gal as retro stated

 

That ( i would assume) is why many older saws and boat motors were 32:1. Because it's a straight up 4oz per gal. Easy to remember & mix.

 

Better cooling systems, better metallurgy, better machining and better oil is why less oil is needed.

I just read this post and the first few replies. I must ask......how did you own this for thirty years and not know about all the problems?

I've had a twist throttle on every wheeler I've owned. I'm a dirt bike guy and wouldn't have it any other way. All my old dirt bike friends Love it. R

10 hours ago, Fishfiles said:

 

 

I have never personally had a twist grip on a ATV ,  also never heard anything good about having one on a ATV  till today 

I guess you forgot about the huge debates on the old sight.  I bought up the sunject way back then in 2014 when I joined. The only problem is leaving it in gear with the engine running. You get off to do something and grab the bar to pull yourself up and twist the throttle instead. Lol it's happened a few times. I warn my friends about this.