TrxPipUK

46 minutes ago, shadetree said:

air fuel mixture jet/screw, bottom front of carb, this is where you set your air to fuel mixture.

Okay so that controls air and fuel mix? Am I right in thinking the more you screw it in the less fuel the engine gets? 

What about the screw on the side? I think it's near the idle adjustment. 

4 hours ago, _Wilson_™ said:

in the last video ... sounds to me like she's running Rich. at idol. and when you give it throttle your giving just the amount of air to allow the fuel air ratio equal out ie the engine revs. if it's a vacum leek, it should idol high most of the time. 

Hmm okay... are there separate air and fuel screws? Or is it controlled by the screw on the bottom of the carb? 

Still haven't got my head around what screws do what lol.. I know what the idle does though haha

4 hours ago, oh400ex said:

 

Sounds like a vacuum leak.

Being that there is no throttle side diaphragm on this model (as we discussed earlier) the next primary suspect is the intake boot.

 

In the most simple terms... air is getting somewhere it shouldn't.

There are a few different possibilities that come to mind...

Leaky intake boot, improperly lapped/adjusted valves, carburetor/throttle adjustment and worn-out parts...

If the throttle is hard to push (at all) there may be resistance in the slide or cable causing this symptom.

Don't think it's that due to it revving up on its own though... hard to tell from video.

 

There are a few different checks that can be done to test for leaks around the intake boot.

The most common is to spray carb cleaner or starting fluid around the area to see if any is sucked in causing a noticeable difference in RPM.

That way is arguably dangerous due to the possibility of the flammable liquid combusting so is frowned upon by some.

My counter-point to that argument is that the amount needed for the test is so minimal that if it did catch fire would quickly burn away before causing further damage (assuming it didn't light something else in the process) (AKA use common sense!)

If you choose to do the test make sure you use very short bursts and give time for the product to evaporate before going further. 

 

Greasing the boot before installation (lightly) will sometimes make up for a slightly worn boot.

Some folks who run in deep water will use a large amount of grease around all sealing points as an attempt to prevent water from coming in.

 

 

Okay great thanks. I'll check for a vacuum leak.

Is there any chance the piston in the carb is sticking or something? 

Hi all.

Wondering if anyone can help me with an issue I'm having? 

Basically I think the carb is either sticking or there's a fuel issue. It idles okay but then when you rev it up and let off it stays quite high for a few seconds before dropping down to idle speed again. Also it revs up by itself sometimes after giving it some throttle. 

I'm pretty puzzled about what's happening with it so help would be amazing. Thanks 

https://youtu.be/OB5gOOD5WjY

9 hours ago, retro said:

 

There are lots of errors scattered throughout Honda's factory service manuals. Ya get used to seeing incorrect info after reading a bunch of them. The cam chain tensioner is mounted in the same location on all the TRX350 years/models (rearward of the chain/guide) so all TRX350 crankshafts rotate the same direction.

 

 

The flywheel is bolted directly onto the end of the crankshaft taper. They rotate as one....

Thanks again retro for setting us all straight lol

8 hours ago, Goober said:

I gotta apologize to @TrxPipUK and @oh400ex for trying to lead you astray.
 

well in my defense You were trying to advance the engine using the kick start and peep thru the timing hole! who does that it way anyways  lols!?

No apology needed Goober! 

4 hours ago, oh400ex said:

 

Can look on the frame's model sticker to find out if you haven't already. 

I don't have the sticker on the frame unfortunately as the frame was blasted and powder coated 

23 minutes ago, _Wilson_™ said:

what manual are you using, pip ? 

This is the manual I am using 

27 minutes ago, Goober said:

The manual says to turn the flywheel in clockwise direction; hard for me to believe this is the first anyone has heard of this editing error.
 @TrxPipUK can you tell us if this is a counter-rotating flywheel? Pop the flywheel cover and pull starter gears. Does the flywheel turn opposite of bottom end?

Hard to believe but it is true.. All I can tell you is that when I turn the engine over with the kicker the flywheel is turning counterclockwise! 100% sure of this, have seen it with my own eyes lol. Not going to take the side off sorry, don't quite have the time to experiment and I am now happy with the engine. It is peculiar as to why the manual is wrong.. but there we go.

Thanks Goober 

1 hour ago, retro said:

Quite a discussion goin' on here eh. The TRX350 motors must be spun counterclockwise when turning the crank on the flywheel-side, same direction as the kick starter spins the crank. When ya spin the crank backwards you can feel your mistake. The crank turns hard cause the chain slack balls up in the front guide and applys lot of extra force against the dog-leg shaped rear guide.... you are putting a lot of stress on the rear chain guide and forcing the timing chain adjuster plunger back which can make them slip & the chain might jump a tooth or two.... don't ever turn a cam-chain equipped motor backwards intentionally. There is no such thing as timing the cam on a single cylinder 4-stroke motor 180 degrees out because the ignition fires BTDC on every revolution. You adjusted the valves correctly PIP!

Thankyou everyone and thankyou @retro for stepping in and giving an explanation, much appreciated. 

Makes a lot of sense that the engine turns over counterclockwise as that is the way the kickstart turns it over (I have checked multiple times now lol). My biggest question is why does the manual say to turn it clockwise when that is definitely NOT the correct direction.. very confusing. Thanks again for clearing that up retro, I'll turn the engine over counterclockwise and check all is okay. 

Thankyou everyone 

2 hours ago, Goober said:

Sounds incorrect @TrxPipUK

Set the valves on the compression stroke—after intake valve Open/closure —you’re looking for the timing mark just after—And before exhaust valve movement.

 

your exhaust valves will be too loose otherwise 

you’re not 180 out but on the exhaust stroke the exhaust valves are on their way to being but may not yet be fully seated. This makes complete sense to me because you complained the exhaust valves were too tight. Now I’m sure they are too loose.

I think I'm just struggling to find TDC on the compression stroke.. At one of the TDC's the intake valves begin to shut but before they do the exhaust valves are beginning to open. It's like they're both just off their seats. This doesn't seem like the compression stroke as there is no resistance when turning the engine and there is no clearance between valve stems and the rocker.

At the other TDC there is compression when the piston is coming up and once the valves seat then there is a lot more movement of the piston before any valves open again, there is also clearance between the valve stem and rocker. So this seemed to be the compression stroke to me apart from that the last valves to close were the exhaust and not the intake, maybe it would make more sense to turn the flywheel round anti clockwise and see if it's easier to find the compression stroke that way.

Am I right to be turning it clockwise? When I used the kickstart the flywheel turned round in a anti clockwise direction. Surely it would be better to turn it over by hand that way as well even though the manual says turn it clockwise? 

I hope my little ramble there makes a bit of sense.. I don't know why I'm finding it so hard to get the piston and valves in the correct position lol

15 minutes ago, oh400ex said:

 

Are you possibly turning the motor backwards?

Does it turn the same direction when moving the motor with the kicker instead of the ratchet?

Dunno if that would produce what you are seeing...

 

Edit: If there was a serious problem it would not run. It is either not susceptible to the "180 out" or timed correctly.

That is a good point! I'll check which direction it turns with the kicker. However, I am turning it clockwise as the manual says to.

As long as it's not going to be damaging the engine in some way then I'm happy to just run it as is.

Thanks 

23 minutes ago, oh400ex said:

 

Generally confused a bit but think you may have it timed at "180 out"

Honestly... it may not even matter. I never personally do anything but time on the compression stroke... 

This article may help clarify a few things... took a few of the highpoints but feel free to give it a closer look

Edit: Confused after watching the video... not sure what I'm missing but something...

 

 

 

Yes I am confused about it as well...

Reading that article and surely if it was 180 out then it wouldn't run? Will it be okay running like this or will I have to go back into the engine and and sort it out properly? 

I can't see how it would be like this though.

I remember when setting the timing I thought it looked all backwards when turning it over, but I had the timing spot on so I went with it.

Can I just run it like is? 

On 12/12/2020 at 11:25 PM, oh400ex said:

 

Yes the engine needs to be at top-dead-center but on the compression stroke. Make sure the mark is perfectly lined up and that the piston is at TDC.

Intake > Compression > Ignition > Exhaust 

You can have the piston at the top on the compression stroke or the exhaust stroke just make sure it's on the compression stroke.

Basically... if you saw the intake valve close just before getting TDC... you got it!

If you just saw the exhaust close it would be wrong.

 

Service manual does explain this fairly well if you would like a more precise explanation.

 

Good luck with it!

Just looking at the valves to check the clearances again seeing as I had the carb off. 

And looking at it whilst turning the engine over by hand it seems as though the compression stroke is straight after the exhaust valves shut... this doesn't seem right? I've got the spark plug in as well so I know when the compression stroke definitely is. 

Does anyone have an explanation as to why it's like this? Would the valves be set right as long as it's on the compression stroke?

Funny thing is that it runs so surely everything is fine? Lol

I'll get a video 

Thankyou both very much! I will report back when I do it, will probably be on the weekend 

15 hours ago, Goober said:

Pilot screw adjustment first page 4-16

 

Page 4-13 4-14 

synchronize the throttle link to the piston valve. Be very careful not to over adjust the throttle link slot metal—if you break it you will be looking for a donor carb.

 

Afterward synchronize the butterfly with the throttle stop screw so you have the butterfly dead closed when installing the cable. Before I install the carb i make a mark on the throttle drum to more easily see the dead zero idle setting. 
here’s where i start

i advance the throttle stop screw just until the Throttle Drum starts moving and the butterfly starts to open. I back it off to zero and use an indelible marker and ruler to make a little mark on the carb body. See my little yellow mark in the picture?

When you install the throttle cable, you have to insert the cable end into the carb body—don’t attach to throttle drum yet! Screw the cable to the carb first but leave it loose. Adjust your handlebar cable adjuster so you can balance the cable slack.

Position the carb in the boot and straighten up the cable—no twists or kinks. then connect the cable to the throttle drum. Then take out the slack—watch that little zero mark—you dont want to tighten the cable too much and unintentionally advance the throttle. Snug the cable lock nut and carb boot.

 

 

Thankyou Goober. Plenty information for me to be getting on with. I'll go over the carb and sort it out. Thanks 

14 minutes ago, oh400ex said:

Always tough to tell from a video but the motor sounds great!

 

Few things stand out to me...

Battery sooner than later... the stator is working overtime... "failure to discharge" was the term the forum came up with I believe. 

Idle seems low. More of a preference but too low can more easily show the instabilities.

There may be a vacuum leak somewhere... heard a bit of delay in increase and decrease of RPM.

Tiny holes in the throttle slide diaphragm would be my first suspect if something else doesn't stand out.

 

Okay great thanks! 

So I'll charge the battery up as soon as possible and I'll have a play with the idle speed, see what sounds best. 

When you say a vacuum leak, where might that be? In the engine? 

And lastly, what is the throttle slide diaphragm? I haven't come across it before.  

Thankyouuu 🙂

1 hour ago, Goober said:

I couldn’t really hear it.

do you have a muffler on it? I hear the wop wop wop like the can has a hole in it.

 

Carburetor synchronization off a little perhaps —what’s the setting of your pilot needle—1 and 5/8ths? 

Yes has a muffler on it, I welded up all the little holes I could find in it as well then painted it.

Yea could well be carburetor synchronisation as I don't know what that is haha... I'll have a look over the manual. Is that adjusted by one of the screws on the outside of the carb? I'm aware that there is an air/fuel mix screw somewhere as well. Is that worth looking at as well? 

Thanks Goober

I fixed the problem of not drawing fuel from the tank with a couple fresh o-rings in the petcock. 

Now I have had it started up (have to kick it because the battery is flat) I've noticed at idle the engine seems a little inconsistent? Not sure if it's normal or the carb needs tuning or what? Hopefully it's noticable in the video. Any help would be greatly appreciated once again.

Thanks 

21 hours ago, Fishfiles said:

Congratulations 'PIP' >>>> Been almost a year to the day from when you started on it 

Thank you man! Appreciate all the help you have given 

15 hours ago, Goober said:

Your fuel tank suction lines might have sediment in them. Use about a foot of string trimmer line or old brake cable to ream out those lines.

careful there’s an intake screen at the end of each suction line. Don’t punch through or get the steel cable hung up on the metal screen.

A clogged or bad petcock would also restrict fuel flow

also inspect the fuel hoses for extensive cracking which would cause suction loss.

 

 

Thanks Goober! Have fixed the issue now. It was the petcock not sealing against the tank properly, replaced the o-rings and now it draws fuel fine 🙂

Thanks guys! Yes I will keep you up to date and I'm sure there will be more questions lol..

Pics will follow as well as it comes together 🙂

Thanks, all the best

Earlier today I had a very exciting afternoon! After some fiddling and finding fuel wasn't being drawn from the tank, I put the fuel line to the pump straight into a can of petrol and she fired right up!!

I think the carb needs a little tuning as it needed to run with the choke half on. Apart from that though, the engine sounded great! No tapping or slapping noises or anything, I'll get a video of it running when I start her up again (need to charge the battery as I flattened it lol). 

But most importantly I wanted to say a HUGE thankyou to every single one of you on hear that has helped me and guided me along. I can't name you all but you know who you are! @shadetreethankyou ever so much for getting me the parts that I needed to get this old quad running. 

I can't thank everyone enough! Cheers guys 🙂

So just looking at the valves and the intake is a bit loose at just over 0.13mm, however the exhaust has no clearance at all and is too tight. 

The manual says the clearance for both intake and exhaust should be 0.08mm, so I'll set both to that. 

10 hours ago, oh400ex said:

 

Yes the engine needs to be at top-dead-center but on the compression stroke. Make sure the mark is perfectly lined up and that the piston is at TDC.

Intake > Compression > Ignition > Exhaust 

You can have the piston at the top on the compression stroke or the exhaust stroke just make sure it's on the compression stroke.

Basically... if you saw the intake valve close just before getting TDC... you got it!

If you just saw the exhaust close it would be wrong.

 

Service manual does explain this fairly well if you would like a more precise explanation.

 

Good luck with it!

Okay brilliant, thanks! 

So then at TDC use the feeler gauge between the top of the valve stem and tappet and adjust as necessary. Right?

Thanks once again for the help!