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Leak-Down test completed
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Posted by: fireburns99

I started a thread a while back regarding my engine not running right, and suspected that i could have an air leak somewhere. Thread can be found here: http://www.exriders.com/vbb/showthr...ght=warped+head
Well i just got done building and conducting a leak down test, and i had the following results;
Starting at 5lbs, after 15+minutes i had lost 0.3 lbs. Obviously within specs. So now i'm looking for other possible reasons. Getting ready to go pull the reeds and check them, but other that that i cannot think of anything else that could be causing a lean condition, when i'm running a 180+ main on a stockbore.
So if anyone has any suggestions, i'm open to ideas.

P.S.
Thank yoy 86 Quad for the wonderful thread on building a leak-down tester.

Posted by: fireburns99

Also, should the leak down test be completed when piston is at BDC, or does it matter. I was thinking that if the rings are sealing good that if the intake port is covered then air shouldn't get to the exhaust port and therefore not test the full system. Comments anyone?

Posted by: Scott-300ex

I've never done a leak down test but I would think it would have to be near TDC or you would loose all your pressure and would come out threw the exhaust.

If I were you, I would do another leak down test and squirt soapy water all over the engine and intake and look for bubbles.

If your having to make it run richer like you said your prolly loosin compression, hopefully you did one before so you have something to compare it to. Do a compression test and tell us wut you got, Cuz if your running it richer, then you are loosing some of the fuel its either getting leaked out or its slippin threw the rings or somethin.

Thats my thought.

Posted by: clutch22

you might try spraying ether or some sort of similar flamable spray around your head gasket and base gasket while its running, and see if it speeds the idle up.

Posted by: fireburns99

Scott the exhaust port is plugged using a piece of an old inner-tube. The procedure is found here:
http://www.exriders.com/vbb/showthr...=leak+down+test

And the compression is still well over the 160lb mark. I think the last time i checked after removing the cr head gasket it was 185, with the CR gasket it was 210.

But keep the ideas coming.

Posted by: Aceman

I don't believe it matters where the piston is at in the stroke, the air will get around it by going through the ports anyhow. I used an 1 5/8" expandable rubber plug I bought from ACE Hardware instead of an innertube. It fits perfectly into my ESR billet exhaust flange when expanded, no leaks whatsoever. I also pumped my engine to 10 psi for 10 min rather than 5 psi. Mine didn't drop at all, even when I let it sit for 15 min.

I don't know what's causing your supposed lean condition but when I have a problem I can't figure out I go through it systematically. Just start with one thing and work your way through the whole system, no matter how insignificant you might think it is. Clean the carb, air filter, check reeds, check fuel flow, needle/seat, etc. Check head/cylinder for flatness, keep an eye on coolant, look for bubbling, white exhaust smoke. Just go through EVERYTHING.

Posted by: 86 Quad R

how are the joints on the exhaust? is the cable to cap sealed good? is the cap sealing ok on the carb?

it may be a good idea to replace the cranks seal for the hell of it. there is a remote possibility that the seal were damaged when ya had the blocked exhaust and are only leaking when under WOT. juss a thought. FWIW

Posted by: fireburns99

quote:
Originally posted by 86 Quad R
how are the joints on the exhaust? is the cable to cap sealed good? is the cap sealing ok on the carb?

it may be a good idea to replace the cranks seal for the hell of it. there is a remote possibility that the seal were damaged when ya had the blocked exhaust and are only leaking when under WOT. juss a thought. FWIW

How difficult is it to replace crank seals. I've never torn into the bottom end, i've done plenty of top-ends. Does the motor have to be removed, and the cases split for the crank seals to be replaced?

I have been thinking of possibly buying a 38mm AS and i think this may just be the push i need to buy one. That way i can test whether its the carb leaking. It gives me a reason to tell the woman when she asks why i bought it. haha.

Posted by: fireburns99

quote:
Originally posted by Aceman
I don't believe it matters where the piston is at in the stroke, the air will get around it by going through the ports anyhow. I used an 1 5/8" expandable rubber plug I bought from ACE Hardware instead of an innertube. It fits perfectly into my ESR billet exhaust flange when expanded, no leaks whatsoever. I also pumped my engine to 10 psi for 10 min rather than 5 psi. Mine didn't drop at all, even when I let it sit for 15 min.

I don't know what's causing your supposed lean condition but when I have a problem I can't figure out I go through it systematically. Just start with one thing and work your way through the whole system, no matter how insignificant you might think it is. Clean the carb, air filter, check reeds, check fuel flow, needle/seat, etc. Check head/cylinder for flatness, keep an eye on coolant, look for bubbling, white exhaust smoke. Just go through EVERYTHING.

I didn't even think of an expandable rubber plug, but the inner tube seemd to work fine. It sealed on the first try. After the leak down test i worked my way back and checked the reeds, and they seemed fine. Unfortunately i only get to ride a few times a year, so the motor doesn't see much use. And i've gone through the coolant system after the whole blown head gasket tihng. Maybe i'll rebuild the stock carb, or just replace it with a 38mm AS. I know its going to end up being somthing minute, but such is the nature of engines.

Posted by: 86 Quad R

seal removal isnt that tuff. just takes a little time and patients and the stator side is the easiest.

you'll need to use a sheet metal screw or similar to penetrate the seat face and use a big pair of pliers or vise grips to grip the screw and pull the seal.

follow the instructions in chapter 7 of the manual to access the clutch side seal.

Posted by: fireburns99

hahah, thats funny i was just getting ready to ask whether you were referring to the seals, or the gasket. I've been looking over the service honda schematics. But i must be thinking about the crankcase gasket that would need the cases split.

I'll have to bust out the 'ol clymer manual. Wait after looking at that pic, is that out of the OEM service manual, or the clymer manual? Thanks for the help 86. You wouldn't happen to know of anywhere else to get the seals then service honda would you. It takes forever to get parts. Thanks.

Posted by: 86 Quad R

try a local cycle shop repair/sales or the dealer. you may get lucky and they'll have a pair laying around.

try and find a ole shop thats been around awhile and works on 2 strokers.

Posted by: fireburns99

quote:
Originally posted by 86 Quad R
try a local cycle shop repair/sales or the dealer. you may get lucky and they'll have a pair laying around.

try and find a ole shop thats been around awhile and works on 2 strokers.

haha, now thats a funnny idea. I live in SoCal nothing but the latest and greatest. If its not a 2000 or newer you get this blank stare from people when you say 1987 250R. haha. I think i may give cal-atv a try. They have them listed.

Heres a list of things i'm going to order, do yuo tihnk this covers my basis:
Honda TRX250R New Left Crank Main Seal
Honda TRX250R New Right Crank Main Seal
Honda TRX250R New Clutch Cover Gasket
Honda TRX250R New Ignition Cover Gasket

These two i'm not sure about.
Honda TRX250R New Transmission Countershaft Seal
Honda TRX250R New Shifter Seal

Thank you for the quick help 86 Quad R, if you lived closer i would buy you a beer.

Posted by: 86 Quad R

hell ya may aswell buy a complete seal kit at this point. lol but, seriously tho. replace the counter ballancer holder o-ring while ya in there. cant hurt.

on a side note:

on rare occasions. when going back with the clutch side "seal race" (highlighted in above pic) that fits over the "splined" end of the crank shaft will want to leak between the race and the crank splines. this is ment to be a machined seal between the race and the face of the crank bearing. what i do to seal it off is apply either blue lock tite or simply a smear of grease.

this is an oppertune time for you to inspect any other parts of the engine while ya have it down.

man!!! COOLER cold beer would be great right now with the triple digit temps we're having lol

Posted by: fireburns99

quote:
Originally posted by 86 Quad R
hell ya may aswell buy a complete seal kit at this point. lol but, seriously tho. replace the counter ballancer holder o-ring while ya in there. cant hurt.

on a side note:

on rare occasions. when going back with the clutch side "seal race" (highlighted in above pic) that fits over the "splined" end of the crank shaft will want to leak between the race and the crank splines. this is ment to be a machined seal between the race and the face of the crank bearing. what i do to seal it off is apply either blue lock tite or simply a smear of grease.

this is an oppertune time for you to inspect any other parts of the engine while ya have it down.

man!!! COOLER cold beer would be great right now with the triple digit temps we're having lol

I wish they would just sell a complete seal kit. So that way i wouldn't have to worry about making sure i get them all. And now i need to find the counter ballancer holder o-ring.

And i'll keep that clutch side seal race thing in mind. Might as well be thorough while i'm at it. I'm kind of amazed at how much you can get too without splitting the cases. I wish i could get ahold of C-Leigh so i could have my jug bored out to 0.60 over, and do the top end so that i have my *** covered.

And i hear you about the beer thing, its been triple digit here as well, except we don't have the humidity. I have a place around here that i hit up, nothing like a frozen glass and a really cold draft.

Posted by: 86 Quad R

pffft

draft gives me head aches

i like a Cooler Cold bottle beer lol

try THIS site

Posted by: fireburns99

That is a great site, it will make it much easier to order. Can the gaskets for the clutch cover and igntion cover be reused, or do i need to order the replacements.

And now i get what you are saying that perfect chill that you can only get from a cooler. But the only thing i drink out of a bottle is Corona. haha. Its a california thing. You want to know what great the new "Miller Chill". Btw i was being sarcastic don't waste your money on that s****. haha.

Posted by: 86 Quad R

yup you can re-use em as long as ya are careful but, i'd order new as back up. i keep extras.

Posted by: clutch22

I've reused new clutch cover gaskets with no problem. I use silicone on them, so they come right off without ripping.

Posted by: fireburns99

Yea i figured you could probably re-use them but to be on the safe side i just ordered a new gasket kit. You can never have too much extra stuff.

Posted by: fireburns99

quote:
Originally posted by 86 Quad R
seal removal isnt that tuff. just takes a little time and patients and the stator side is the easiest.

you'll need to use a sheet metal screw or similar to penetrate the seat face and use a big pair of pliers or vise grips to grip the screw and pull the seal.

follow the instructions in chapter 7 of the manual to access the clutch side seal.

Hey you wouldn't happen to have anymore of chapter scanned into your computer would you? That way i don't have to go by the oem service manual. I have the Clymers manual, but it didn't seem to cover this so well. Thanks, 86. I already got that seal kit, its nice being an hour away from these shops. BUt one question i had is there seems to be a lot more seals than i thought. Do i just need the 2 main crank seal, or can they all be replaced with the engine still in the bike?

Posted by: 86 Quad R

have you got dsl and do you have plenty of disk space?

Posted by: fireburns99

I'm at work with a T1 line, and 5TB server!!!

haha

Posted by: 86 Quad R

you have mail.

Posted by: fireburns99

I just have one question. Did you really scan all 244 pages???? Because if so wow.

Posted by: 86 Quad R

Posted by: fireburns99

Thanks alot 86. Already printd out and bound. haha.

Posted by: 86 Quad R

you should now be able to tackle any of your R's mechanical needs ehhh

Posted by: xlr810

Swap out your carb to one from a 250R that runs properly.

I had a clogged passage on one of my old stock carbs. Normal jetting for it was 165-170 main. I went all the way up to a 200 main, and it was still acting lean at the top end. I swapped a different carb onto it, and 165 was right again, with no lean spots anywhere.

Clean that carb! Completely. Thoroughly. Your leakdown test sounds within specs. It is certainly worth a try. Replacing all the seals is a lot of work.

Posted by: fireburns99

I've got a brand new 38mm A/s on the way!!

Maybe i'll throw that on there first for the hell of it. But thanks for bringing up that clogged passage, i've torn the carb apart and checked float height and all that, but didn't check the passages. Thanks xl80.

Posted by: Scott-300ex

Hey dude, just soak it in a pan of cleaner for a night, after you take the float bowl and float and needle out, and everything like that, then the next morning take carb cleaner and put the straw on it and shoot threw every little opening in the carb untill you see it coming out threw the exit whole somewhere.

Posted by: fireburns99

quote:
Originally posted by Scott-300ex
Hey dude, just soak it in a pan of cleaner for a night, after you take the float bowl and float and needle out, and everything like that, then the next morning take carb cleaner and put the straw on it and shoot threw every little opening in the carb untill you see it coming out threw the exit whole somewhere.

I'll do that just for the sake of my own curiosity. But either way i'm prolly going to have the cylinder bored and honed, and then put on the 38 mm carb.