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

Willythegame · Member

Starter assembly problems

hanzo · Senior Member

Doesn't look there meshing properly from pics which would explain a lot I would strip it down a damaged sprag will get worse and there is no fix .Damaging all related components and metal fragments going through the engine.have you looked at oil filter for any signs of metal particles.

Willythegame · Member

Can't say I have. Going to order up the new sprag this week and get that installed , I was hoping I'd get by on a new gear and sprag . New gear,sprag and motor is looking like a costly operation 😥😥

TTRfan · Super Guru

Welcome to the forum! Please don't forget to put a bit of detail on your profile please wink

It would be a shame to replace all but one component and suffer damage again.

Pull the starter motor out and have a good look at the pinion. If it looks at all like this then don't use it again

There are some cheaper alternatives to buying a new starter motor here http://ttr250.activeboard.com/t48824180/starter-motor-problems-and-solutions-megathread/?page=3

EMS starter pinion damage 001.jpg

Willythegame · Member

Thanks guys. I'm going to pull the starter motor tomorrow hopefully to get a look. I'll post updates :)

admbnm · Veteran Member

hi pal,it may be of some interest to you that there are 2 different setups/ratios for the starter gears as i luckily learnt from on here,a mis-matched pair will,i believe go in but obviously lead to mechanical failure,all the best and good luck

TTRfan · Super Guru

Well picked up Martin! This is the thread you refer to http://ttr250.activeboard.com/t52922697/replacing-the-starter-idler-gears-beware/

Brian

Willythegame · Member

Ah ok Guys so from a quick glance earlier bikes may have a smaller Idler/starter gear? The bike is an 05 , I still haven't managed to get down there to pull the starter and get a look. Might manage tonight. Pain in the arse, but well worth doing, i like this bike alot.

TTRfan · Super Guru

As your TTR is an '05 then your gears are almost certainly 72T/19T (part #4GY-15512-01-00) and 16T/14T (part #4GY-15517-01-00) but best to wait and do the tooth count wink

Brian

hanzo · Senior Member

TTRfan wrote:
As your TTR is an '05 then your gears are almost certainly 72T/19T (part #4GY-15512-01-00) and 16T/14T (part #4GY-15517-01-00) but best to wait and do the tooth count
Brian

O5 isn't that the possible year of registration looks like a metal tank oe on Sig pics so best to have a tooth count mine ran the 72/20 and 16/15 small idler . The 72/20 obsolete but I believe the 16/15 small idler can still be purchased .

ttr steve · Super Guru

Yep only the 72/19 and 16/14 available new now, but I still have the earlier combo in great used condition in the shop. Or 16/14 can be ordered new on it's own.

https://totallyttrs.com/epages/699105d9-e4cc-4b32-b236-84e72cd67f84.sf/en_GB/?ObjectID=1655063&ViewAction=FacetedSearchProducts&SearchString=idler+gears&=&SearchButton=

-- Edited by ttr steve on Monday 20th of February 2017 07:10:19 PM

-- Edited by ttr steve on Wednesday 22nd of February 2017 07:00:29 PM

Willythegame · Member

Hey guys pulled the motor today. Removed it from the stator side as it seemed easier with an after market shock reservoir really getting in the way clutch side. Starter is caput as is the gear pictured. Also not even a trace of gasket when removing the side case

Willythegame · Member

Large idler/starter seems actually not bad

ttr steve · Super Guru

Oh Dear Oh Dear

A few of us have been here before cry

You need to inspect your sprag clutch, as the damage you have shown us is the effects of a knackered sprag, kicking back through the idler gears and shredding teeth all the way back to the starter pinion.

You have your work cut out, but all is do able and lot's of threads about it on this forum. (just use the search box)

There is going to be lots of shards in the bottom of your engine, is there a magnetic sump plug fitted and have you inspected it?

Quite a few really good used parts are available in my shop, this might help you save a bit of money.

Also there is some good threads about starter motor alternatives on here. Someone from the forum bought a cheap starter from ebay, not sure how they got on with it? I had one and the pinion seemed to be made of cheese.

Sure there will be lot's of others along soon with good advice.

Steve

hanzo · Senior Member

Can safely say thats fubar mate .Thats what an ignored sprag does looks to be quite a bit of material missing so you need to have a good go through id check the strainer in the bottom of clutch side housing see whats floating about and see if theres any glitter bits of metal in the filter too .Make sure you keep hold of the shims on the gear too as youll need them also check condition of the needle bearings in both gears.the sprag is a fairly straight forward job but it helps if you got a couple of tools to hand. A flywheel puller... but you can get away with using the rear axle at a push good torque wrench and an impact wrench is handy for the flywheel bolt Brians excellent guideto sprag replacement on here is handy to have in the stickys section.. the basic rule is if its not 100% replace it as there is no alternative .You need to check the condition of the boss on the large gear as well .basically start from backwards and work back to the starter motor.

Willythegame · Member

Thanks guys.
Steve right off the bat I need a new sprag , the tank is metal so i need whatever starter gearing that indicates. The small starter gear pictured has 17? Teeth though I'm not sure if someone has reinstalled in the past and potentially fitted the wrong size. I also need the stator side case.

There was a fair bit of loose metal kicking around the big hear boss is lightly scratched. The plug was magnetic and there was alot of sediment there also. I also dropped the oil, it was grungy but there was nothing overly concerning metal wise.

Thanks again

ttr steve · Super Guru

Happy to help.

All the parts you need are in the shop https://totallyttrs.com/epages/699105d9-e4cc-4b32-b236-84e72cd67f84.sf/en_GB/?ObjectID=1655063&ViewAction=FacetedSearchProducts&SearchString=idler+gears&=

You just need to decide whether to go for the 72/19 16/14 combo or the 72/20 16/15 combo

Idler gear 3 is the same for all models, you will need to check yours carefully as advised, as if you put on a new sprag on a knackered boss it will only go again very quickly and they are relatively cheap.

Make sure you check what Dominic has advised.

Make sure you flush the engine out well, you do not want all them missing bits of metal going around once you have put it back together, else you will be doing a barrel and piston re-bore too

Willythegame · Member

Hey Steve which ideal gear 2 comes as standard with this version of the bike? I'm going to purchase both the Large and small idle gear just as I figure with this it's Best to go new than risk. Idle gear 3 looks really good so at least theres that.

ttr steve · Super Guru

It is not just the teeth on gear 3 you need to check, it is very important you check the boss that the sprag runs on. Below is a picture of what a damaged one looks like. Groves were the pink mark is, if you can feel anything there it has had it.

Robins sprag 4.jpg

Your choice of combination seeing as you are changing both

Idler gear 1 72/19 used with Idler gear 2 16/14 (If you are going with new, this is your only option).

Idler gear 1 72/20 used with Idler gear 2 16/15

Hope that helps.

Steve

-- Edited by ttr steve on Wednesday 22nd of February 2017 08:45:12 PM

Willythegame · Member

I haven't been that far yet, I'll be able to inspect when preparing for the new sprag.
Hopefully we've avoided that trouble
Thanks again

-- Edited by Willythegame on Wednesday 22nd of February 2017 09:52:47 PM