A forum for owners of Yamaha TTR250 trail and enduro bikes!

TheWizardofOdds · Senior Member

heat protection for battery housing

Fladdem · Senior Member

It has happened to mine, I assume, as there is a hole melted into the bottom, front left corner, closest to the header pipe. I left it, the battery isn't going to fall through it. I wouldn't worry about a little hole in the corner of the box, personally.

Having said that, I just re-read your post, the hole in my box, is only big enough for a little finger to fit through. If yours is two inches across, that's quite big and may cause structural un-soundness. Are the mounting bolts for the box loose? Could have caused it to slip and sit on the exhaust?

-- Edited by Fladdem on Sunday 6th of April 2014 11:05:59 PM

TheWizardofOdds · Senior Member

Fladdem wrote:
It has happened to mine, I assume, as there is a hole melted into the bottom, front left corner, closest to the header pipe. I left it, the battery isn't going to fall through it. I wouldn't worry about a little hole in the corner of the box, personally.

Having said that, I just re-read your post, the hole in my box, is only big enough for a little finger to fit through. If yours is two inches across, that's quite big and may cause structural un-soundness. Are the mounting bolts for the box loose? Could have caused it to slip and sit on the exhaust?

-- Edited by Fladdem on Sunday 6th of April 2014 11:05:59 PM

The box isn't sitting on the exhaust and is about two or maybe three inches apart, I'd need to double check tomorrow. The first hole was on the outer edge of the box and was long and narrow but the hole directly underneath the battery is quite big and is sure to get worse.

I'll try to post pics and have a look again tomorrow, thanks.

TT-R250M · Super Guru

The battery box and the RHS side panel should have an aluminum insulated cover to stop the exhaust from burning them. See parts N8. and 14 in the link below-

http://www.partzilla.com/parts/search/Yamaha/Motorcycle/2000/TTR250+-+TTR250MC/SIDE+COVER/parts.html

I can't say I have ever had that happen but I have the insulators fitted.

If you are experiencing a red hot exhaust, it would be a good thing to check that you are not running lean. Running too lean can burn out the rings as the engine needs enough fuel to cool the piston/cylinder down. In extreme cases it can burn a hole in the piston.

Jarrah

TheWizardofOdds · Senior Member

TT-R250M wrote:
The battery box and the RHS side panel should have an aluminum insulated cover to stop the exhaust from burning them. See parts N8. and 14 in the link below-
http://www.partzilla.com/parts/search/Yamaha/Motorcycle/2000/TTR250+-+TTR250MC/SIDE+COVER/parts.html
I can't say I have ever had that happen but I have the insulators fitted.
If you are experiencing a red hot exhaust, it would be a good thing to check that you are not running lean. Running too lean can burn out the rings as the engine needs enough fuel to cool the piston/cylinder down. In extreme cases it can burn a hole in the piston.
Jarrah

I dont have either of the insulators Jarrah.

How do you know if the bike is running lean?

I was sent a pdf of the TTR and the parts numbers like the link you've posted Jarrah. As its an Australian Yamaha parts list are the parts numbers valid for the UK? If I was looking for certain parts from a UK dealer would these be the parts numbers they would use?

TheWizardofOdds · Senior Member

TT-R250M · Super Guru

Wow, looks nasty!

Yeah, the part numbers will be the same in the UK.

It can be hard to tell whether you are running lean as it will only show symptoms if it is extremely lean. There is numerous ways to tell whether you are running lean- over-heating, red at the header pipe, needs a lot of choke on start-up. backfire on acceleration, whitish deposits or a clean spark plug all indicate a lean condition. Bear in mind that you may not have any of the symptoms described. On the other hand, running rich is easy to tell- backfiring when the throttle is let off, splutters until full throttle, slow acceleration, flat spot on acceleration, black deposits on the spark plug etc..

I would suggest that you drop your jet needle clip position down two settings (towards the sharp end). If it sputters or backfires when the throttle is let off, it means that it is rich and you should return the jet needle clip position back to where it was. If you find that it has better acceleration or runs better, it means that you are running lean- try going down to the last setting (closest to sharp end) and if it still runs fine- you may need to go larger on main jet. Of course, if it's happening below 1/3 throttle and cools when you go to full throttle, it means that the pilot jet is too small.

Jarrah

TTRfan · Super Guru

Is that the replacement battery box I sent you Dave?

I have run a lot of battery boxes without the insulation (the insulation's glue tends to die with age and it comes off with power washing) without such a problem confuse

Your carb will have the standard UK jetting inc. a new pilot jet which, together with the fact that your mechanic raised the needle, makes me fairly certain your mixture is OK.

I think we have to turn to other possibilities,

The engine is still tight after its rebore so will run slightly hotter than a fully run in engine.

The airflow over the engine once the TTR is being ridden should keep everything, including the battery box, cool enough.

Are you possibly running the engine for any length of time with the TTR stationary (not good for an air-cooled engine)? This is all I can think that might cause the melt down of the battery box.

Brian

PS If you need another battery box (with insulation!) just let me know wink

TheWizardofOdds · Senior Member

TT-R250M wrote:
Wow, looks nasty!
Yeah, the part numbers will be the same in the UK.
It can be hard to tell whether you are running lean as it will only show symptoms if it is extremely lean. There is numerous ways to tell whether you are running lean- over-heating, red at the header pipe, needs a lot of choke on start-up. backfire on acceleration, whitish deposits or a clean spark plug all indicate a lean condition. Bear in mind that you may not have any of the symptoms described. On the other hand, running rich is easy to tell- backfiring when the throttle is let off, splutters until full throttle, slow acceleration, flat spot on acceleration, black deposits on the spark plug etc..
I would suggest that you drop your jet needle clip position down two settings (towards the sharp end). If it sputters or backfires when the throttle is let off, it means that it is rich and you should return the jet needle clip position back to where it was. If you find that it has better acceleration or runs better, it means that you are running lean- try going down to the last setting (closest to sharp end) and if it still runs fine- you may need to go larger on main jet. Of course, if it's happening below 1/3 throttle and cools when you go to full throttle, it means that the pilot jet is too small.
Jarrah

Thanks Jarrah.

The bike runs fine, no backfiring, accelerating well, choke is only on for 15secs or so and is now no problem at all. I would be reluctant to meddle with the carb as its just been serviced by a mechanic. I haven't checked the spark plug though so that's next.

TheWizardofOdds · Senior Member

TTRfan wrote:
Is that the replacement battery box I sent you Dave?
I have run a lot of battery boxes without the insulation (the insulation's glue tends to die with age and it comes off with power washing) without such a problem
Your carb will have the standard UK jetting inc. a new pilot jet which, together with the fact that your mechanic raised the needle, makes me fairly certain your mixture is OK.
I think we have to turn to other possibilities,
The engine is still tight after its rebore so will run slightly hotter than a fully run in engine.
The airflow over the engine once the TTR is being ridden should keep everything, including the battery box, cool enough.
Are you possibly running the engine for any length of time with the TTR stationary (not good for an air-cooled engine)? This is all I can think that might cause the melt down of the battery box.
Brian
PS If you need another battery box (with insulation!) just let me know

Brian, that's the original box, I'm not going to install the one you sent until I've wrapped the exhaust and put a heat shield underneath or it'll just melt too.

It doesn't make much sense to me either as I've only taken the bike to work which is early mornings and back in the evening or vice versa so the roads are quiet and I haven't even been as much as held at a traffic light. After the initial problem when it melted and the carb was serviced I've been particularly careful not to idle and the bike is switched off immediately so as not to overheat. So the bike is never stationary for more than a few seconds.

Thanks for sending the box I'll see how I get on in the next few days. I'm going to try local hardware shops for aluminium tape/silver foil and try it out. You can see from the picture that it seems to be concentrated at the join of the exhaust. Hmmm..

Maniot · Veteran Member

I have been using layers of sticky backed 2 inch wide aluminium tape on the underside of my battery carrier. This material is the same stuff as used to seal (usually temporarily) wood burning stove pipes in Greece. When I fitted the new FMF muffler recently I also applied black fire-resistant sealant within the header before slipping in the muffler. I also ensured that the exhaust clamp was well tightened. I imagine any hot exhaust gas leakage in this area would soon melt any adjacent plastic material.

TheWizardofOdds · Senior Member

Maniot wrote:
I have been using layers of sticky backed 2 inch wide aluminium tape on the underside of my battery carrier. This material is the same stuff as used to seal (usually temporarily) wood burning stove pipes in Greece. When I fitted the new FMF muffler recently I also applied black fire-resistant sealant within the header before slipping in the muffler. I also ensured that the exhaust clamp was well tightened. I imagine any hot exhaust gas leakage in this area would soon melt any adjacent plastic material.

Your box isnt melting anytime soon, that's for sure.

Good point about the clamp. I'll have a chance to take a look properly tomorrow and see if the exhaust clamp is loose. It seems to be melting at the same spot. Thanks.

TheWizardofOdds · Senior Member

I've taken the battery out and tightened the clamp about one turn to a turn and a half. Here's a photo of the are which melted the underside of the box. Should the metal ring to the right of the clamp be there? Or beneath the clamp? Does everything look as it should here?

fast fazer · Member

Is the Gold coloured ring to the Right of the clamp not meant to be inside of the clamp so it makes a seal on the front pipe?

You normally have a Lead like ring that goes into the wide part of the rear pipe that seals onto the front pipe when the clamp is tightened.

Is the exhaust gas tight or can you feel it blowing out at the clamp?

Regards, ff.

TheWizardofOdds · Senior Member

fast fazer wrote:
Is the Gold coloured ring to the Right of the clamp not meant to be inside of the clamp so it makes a seal on the front pipe?

You normally have a Lead like ring that goes into the wide part of the rear pipe that seals onto the front pipe when the clamp is tightened.

Is the exhaust gas tight or can you feel it blowing out at the clamp?

Regards, ff.

I would of thought that should be under the clamp too but its stuck fast and doesn't slide at all. I'm not sure what it is?

I'm going to put the battery back in in the new box and fire it up and take a look, briefly, I don't want to melt this one.

TT-R250M · Super Guru

TheWizardofOdds wrote:
fast fazer wrote:
Is the Gold coloured ring to the Right of the clamp not meant to be inside of the clamp so it makes a seal on the front pipe?

You normally have a Lead like ring that goes into the wide part of the rear pipe that seals onto the front pipe when the clamp is tightened.

Is the exhaust gas tight or can you feel it blowing out at the clamp?

Regards, ff.

I would of thought that should be under the clamp too but its stuck fast and doesn't slide at all. I'm not sure what it is?

That is the exhaust collar, it is there so that you know when the muffler is far enough forward. It does not seal the muffler in any way. Yours looks to be not sitting against it from the picture and may need to be loosened and pushed forward a tad.

Jarrah

TTRfan · Super Guru

The collar is a standard fitment on all standard TTR250 exhaust header pipes. Yours is correctly placed Dave - it is there to help position the exhaust box.

In my experience it is extremely unlikely that a properly tightened up clamp will leak. The graphite collector box seal used between the clamp and header is a brilliant device wink

I have Motad exhausts fitted to my TTRs so can't take a pic to show you.

Brian

TT-R250M · Super Guru

Oh, in case you didn't know, you seem to be missing a muffler bolt-

Jarrah

TheWizardofOdds · Senior Member

TTRfan wrote:
The collar is a standard fitment on all standard TTR250 exhaust header pipes. Yours is correctly placed Dave - it is there to help position the exhaust box.
In my experience it is extremely unlikely that a properly tightened up clamp will leak. The graphite collector box seal used between the clamp and header is a brilliant device
I have Motad exhausts fitted to my TTRs so can't take a pic to show you.
Brian

Thanks Brian. I just wondered if it had shaken loose or something, I know why these things are called thumpers now!

I've put the box in you sent me and will monitor it carefully. I'll order some Ali tape too and it should be fine.

TheWizardofOdds · Senior Member

TT-R250M wrote:
Oh, in case you didn't know, you seem to be missing a muffler bolt-
Jarrah

Yeah thanks Jarrah I knew.

As I mentioned to Brian I know why they're thumpers now. A few bolts seem to have shaken loose or I've not tightened enough. Need to keep a check on it.

fast fazer · Member

TTRfan wrote:
The collar is a standard fitment on all standard TTR250 exhaust header pipes. Yours is correctly placed Dave - it is there to help position the exhaust box....

Shows how long I haven't seen my bike for doesn't it smile

Regards,ff.

TT-R250M · Super Guru

TTRfan wrote:
The collar is is there to help position the exhaust box....

The exhaust box? how would the collar help to fit it to this exhaust box you speak of? Just having a dig. wink

Anyway-

That is the exhaust collar, it is there so that you know when the muffler (AKA- silencer) is far enough forward. It does not seal the muffler in any way. Yours looks to be not sitting against it from the picture and may need to be loosened and pushed forward a tad. Edited: but it is usually the bottom that butts up to each other so it may be correct?...

If you can't get that missing bolt in, you'll know why at least.

Jarrah

TheWizardofOdds · Senior Member

TT-R250M wrote:
TTRfan wrote:
The collar is is there to help position the exhaust box....

The exhaust box? how would the collar help to fit it to this exhaust box you speak of? Just having a dig.
Anyway-
That is the exhaust collar, it is there so that you know when the muffler (AKA- silencer) is far enough forward. It does not seal the muffler in any way. Yours looks to be not sitting against it from the picture and may need to be loosened and pushed forward a tad. Edited: but it is usually the bottom that butts up to each other so it may be correct?...
If you can't get that missing bolt in, you'll know why at least.
Jarrah

What size is the bolt that's missing?

I've got some silicone rescue tape from a local hardware shop. Its heat resistant to 260 degrees Celsius. Rescue tape. I'll wrap that under the box and the clamp possibly, see what happens.

TT-R250M · Super Guru

The bolt is M8 and needs to be anywhere between 15-20mm long. I like to use a large M10 washer (or a loose fitting M8 washer) that I offset towards the frame rail to protect the exhaust mount from snapping off (common problem it seems, happened on my old OE TTR). In addition to the large washer I use a split-washer so it doesn't come loose...

That tape sounds alright, if that doesn't fix the ''melted battery problem'', I suggest that something else is going wrong. It should not get that hot surely.

Jarrah

TheWizardofOdds · Senior Member

Its all purpose tape. An american one I think, it costmore than seems reasonable on tape but it seems like its real quality stuff. I'll take the battery out again tomorrow and layer the tape properly underneath and at the clamp which is where its melting the box. I'm confident it should be OK after that. Like I said, the bike is running nicely now so fingers crossed .

Thanks for the information regarding the bolt. My plan is to replace all the nuts and bolts/screws that need replaced. Should I order a load from Yamaha? I like the idea of having original equipment ones on the bike. Or do most people here just use ones from stores?

TT-R250M · Super Guru

I use stainless steel Allen key head bolts for everything other than bolts over M8. I use OEM bolts for all other bolts. It makes it easy to do a service and also means that I don't need so many tools when in the bush.

Jarrah

Bugeye_bob · Veteran Member

do you have access to an IR temp reader at all?
It may be worth doing a few temp tests and reporting back, see what other members are getting after the same time periods.
I know around the guard it is around 160 degrees, but the downpipes can reach 280,
I will try doing a few sample test on the area in question and let you know.

TheWizardofOdds · Senior Member

TT-R250M wrote:
I use stainless steel Allen key head bolts for everything other than bolts over M8. I use OEM bolts for all other bolts. It makes it easy to do a service and also means that I don't need so many tools when in the bush.
Jarrah

I just do road riding on my TT so just the ordinary ones for me I think.

TheWizardofOdds · Senior Member

Bugeye_bob wrote:
do you have access to an IR temp reader at all?
It may be worth doing a few temp tests and reporting back, see what other members are getting after the same time periods.
I know around the guard it is around 160 degrees, but the downpipes can reach 280,
I will try doing a few sample test on the area in question and let you know.

No, I was wondering about the temperatures. If you can tell me the temp that would be great thanks. I'll get stuck in tomorrow and take the bike out for a blat and see if the tape stands up to the heat. I know that its air-cooled and all that but the bike should still be able to idle without overheating, at lights, junctions etc. The tape can withstand temps of 260 celcius but is a short term fix until I determine if the problems still there or not.

ttboof · Super Guru

ive recently completed a,ride over gge barrington tops first day was a 13 hour 350 k run in 38deg heat with the hardest 7ks taking nearly 5hours out of the 10 bikes the ttr was the only air cooled bike and tge only one not to have over heating issues .

fairly quick pace the rest of the day had an ex world gp/ superbike champ mate on the ride

TheWizardofOdds · Senior Member

ttboof wrote:
ive recently completed a,ride over gge barrington tops first day was a 13 hour 350 k run in 38deg heat with the hardest 7ks taking nearly 5hours out of the 10 bikes the ttr was the only air cooled bike and tge only one not to have over heating issues .
fairly quick pace the rest of the day had an ex world gp/ superbike champ mate on the ride

Impressive. Just out of interest, is your bike modified in any way or stock exhaust etc.?

ttboof · Super Guru

TheWizardofOdds wrote:
ttboof wrote:
ive recently completed a,ride over gge barrington tops first day was a 13 hour 350 k run in 38deg heat with the hardest 7ks taking nearly 5hours out of the 10 bikes the ttr was the only air cooled bike and tge only one not to have over heating issues .
fairly quick pace the rest of the day had an ex world gp/ superbike champ mate on the ride
Impressive. Just out of interest, is your bike modified in any way or stock exhaust etc.?

my bike is fairly stock just a stain tune exhaust , aftermarket bars (the originals bend too easily ) opened up the air box (best mod of all ) , went up one size on the pilot jet from standard , adjusted the throttle stop (mine was one of those they were not opening 100% , 10 weight oil in the forks ( well worth doing ) , 13 to 48 gearing (still ok for open stretches of road ) , B&B bash plate (a must ) and im pedantic with cleaning after rides and on top of maintenance.

one other mod due to a lot of steep hill climbs and an old injury is a gripper seat cover out of marine non slip stuff (sreatches in all directions ) .

the ride I mentioned is typical of rides we do a few times a year the Taree, moonan flat and return (the hard way 2 days 700K 26 hours ) the ttr is usually the only sub 400cc bike and get ridden fairly hard but is always there at the end with no problems I find I carry my tools and spares to support the other guys .

that's what riding a ttr is all about , with a few minor changes the bike can give endless hours of fun and adventure . my tip is to keep the mods simple don't go chasing a miracle as it an ordinary bike that gives extra ordinary results when treated correctly . and this forum is a fantastic way to talk to like minded people who have found the joy that is the TTR .

-- Edited by ttboof on Friday 11th of April 2014 10:29:33 PM

TheWizardofOdds · Senior Member

I've read a bit about those mods like the air box and throttle screw etc. I've a feeling I'll get around to them soon as every little extra helps. I take my TT on the roads and although its A-roads through the countryside the traffic still moves at a fair pace.

I like your bike very much. Its a popular number in Australia it seems.

I have a very limited experience of bikes and have only ridden a few. Although I can see me adding to my stable in the future, the TT has an appeal that's hard to explain. It just feels right sitting on it. It looks great and where I live everyone has sport bikes or f650s or 1200s. Nice bikes but people always seem to notice the ttr.