Yamaha TTR250 FAQ - Updated 24 August 2001

General:
The TTR250 has an air-cooled, 4 stroke, 4 valve, DOHC single with electric start, six (fairly close ratio) speed gearbox and disc brakes front and rear. The Open Enduro model has a well specified suspension set-up with adjustable units front and rear.  The very capable quick-steering front end has a leading axle and air-damped forks with over 10" of travel. The rear has Yamaha's own rising rate monoshock with a remote reservoir that allows adjustment for both compression and rebound damping and about 10" of travel as for the front forks. It has a steel box section frame with a heavy duty ally swingarm and distinctive purple anodised wheel rims which you either love or hate! The engine thrives on revs but has enough bottom end to plonk along at low revs and still pull cleanly from nothing. Quoted at 28bhp @ 8,500rpm.

The TTR is a very civilised traillie that TBM described as being "as civilised as it is competent".  Only a handful of TTRs was imported back in 1995 by Mitsui Yamaha (were these classed as "official" imports does anyone know?) but seem not to have sold well - not because they weren't good bikes - but because of what was described as an "exorbitant" price tag at the time of £4,000 plus. There are basically two models: (pre the Y2K "blue" model) the Open Enduro and Raid. There seemed to be a lot of imports between 93 and 95 (usually white plastics and metal tanks) after which there seems to be a gap until the new "blue" 2000 TTR (plastic tanks) became available and sold officially by Yamaha in the UK. The 2000 models have electric and kickstart making them "dual start" as well as revised steering geometry and suspension. Some of the common parts are interchangeable with other makes of offroaders, i.e. brake pads, but the battery is peculiar to the TTR (and expensive).

How much should I pay for a Yamaha TTR250?
White imports between £1200-2000
2000 models £2,000 upwards

What should I look out for?
Generally not a lot goes wrong on one which has been maintained well. The electronic speedo is very expensive so is an obvious one to check otherwise its the usual four stroke checks (see my comprehensive buyer's checklist ) plus a good run to check handling, clutch, controls, etc.

What gearing should I use for the Trail?
14-52 or 13-48 is good on & off road compromise. Standard is 14-44. Renthal part number for front sprocket is 342A-520-13 or 14 (assuming you are running a 520 chain which I hope you are!). The bigger front sprocket is easier on the chain but chain noise increases when you replace the original Yamaha sprocket which has a substantial ring of rubber built in to act as a bit of a "cush drive" - there is NO cush drive in rear wheel so expect some judder on take off!

What tyres are best for on and off road use?
MT21s do it for me! However, the ideal for UK (muddy and stony) trail riding is probably a MX knobbly on the front and a trials tyre (e.g.Pirelli MT43) on the rear. 

Can I get a big-bore kit for the TTR?

Yep! Paul Bates of Bogbusters International Imports is building a 320 - watch this space! Brian Eland of www.BrianEland.com is also looking at importing SRC big-bore kits. Also, have a look at this American website for tuning stuff for TTR250s - 325 big bore or 350 stroked kits have been available in America for some time - http://www.strokerspeed.com/bikes/ttr250.cfm and http://www.srcinc.net/enginekit.html Rumour has it the 350s can be unreliable though :-(

Can I get a bigger tank for LDTs etc?
Yes - Acerbis did an 22 litre plastic tank.

How can I improve the lights on the open Enduro?
Either (a) fit the whole headlamp assembly from a Raid which are designed for roadwork and are 50/55W compared to the Open Enduro's 33/36.5W. I have just fitted a Raid headlight assembly to my TTR and the difference is amazing - well worth the £40 I paid for the s/h assembly complete. The lighting coil on the TTR produces a healthy output and can run a 100W H4 halogen bulb but check it fits before investing - these bulbs will fit the after-market Acerbis HP lamp which has a glass lens that can handle the heat of the bulb. The standard headlight switch and wires may be suspect running the bigger bulb and it may be worth using heavier gauge wires from the switch to the headlamp.

or (b) install a 250LC pattern headlight and headlight brackets from M&P for a total of £46 (£26 for the light, £20 for the brackets). 
PS If you don't like the "headlight always on" then fit a simple push on and off switch (about £4.00) and splice it into the yellow and black wires just by the left hand bar switch.

Can I get second-hand parts for my TTR?
For UK - try Bogbusters International Imp Ltd (e-mail paulbates@supanet.com) or Brian Eland (e-mail Brian@BrianEland.com) - please let me know if you find another source!

Can I modify the exhaust to improve power?

(a) The standard silencer is very restrictive (assuming you have stock exhaust!) and can be modified quite cheaply (assuming you have access to welding gear) to improve power output. Johnny Davies from Newark, Notts, supplied the following instructions and excellent drawings: Look at the attached diagrams (standard and modified) before reading the next bit so it all makes sense! Cut completely through the existing weld where cylindrical tail section meets the 'box' section then put back on bike and fire it up to find out which 2 pipes are the outlet. Then cut or drill through plate holding the other 3 pipes in place then you can remove them. Grind off original outlet pipe from tail section. Now you need 2 pipes long enough to connect from cut section to the end of the tail section (Johnny used bits off the frame of an old muddy fox mountain bike). Now you need to make another hole in tail pipe and file both holes out to take then new pipes. Spot weld pipes to the 2 outlet pipes and tack pipes together for extra strength. place tail section over new pipes and tack in place then weld up tail to box and finish by welding around the new outlet pipes. Then you end up with a lovely freeish flowing exhaust. 

(b) Setting up the carb to match the exhaust. It is possible to re-jet the Teiki carb using Kiehin jets. What to use depends on what year your TTR is. Early TTRs were 142 main jet and 48 pilot jet though from about 96/97 the main jet was a 147 and pilot was a 50. Johnny's was a later model so he found a local carb specialist that did Kiehin carbs, took in his main jet and needle jet and they tried a standard round Kiehin main jet and it fitted perfectly. They measured his original jet and it was 1.47mm (apparently different makes of jets don't always mean that the no. on the jet is the size in mm) and suggested trying a 148mm, 150mm, and 152mm (Kiehin). Johnny tried them all (about £3.00 each) 148 no difference, 150 spot on, 152 too rich (like running with the choke on). Johnny has left the snorkel off the air box and has the needle on the standard position. He is looking at different needles at the moment, also he has left the mixture screw at 3.5 turns out compared to standard 2.25. The firm he used is:
Allens Performance R & D, Unit B9, Moorbridge Road, Bingham, Notts, NG13 8GG - tel. no. 01949 836733, fax. 01949 836734
You should get better power throughout the range. Phew! Thanks Johnny.

(c) Martin Wilson's TTR had an XR400 tail pipe on it when he bought it. The mounting brackets all line up, it just requires a small adapter pipe between the tail pipe and the header pipe.

What brake pads fit? (Info from Paul Bates - thanks mate!)
 TTR250 brakes same as WR200, rear same as Serow, front same as TS200 and RMX250. Part numbers by manufacturer as follows with rear given first: Apico BP100 and BP002, Vesrah VD432/2 and VD340, FA152/2 and FA?????, SBS SBS648 and SBS SBS611, Ferodo FDB659 and FDB497, Dunlop DP315 and DP411. Good parts shops should have sets in stock but any dealer with a "Hi level" account can get them next day if not in stock. 
I personally use the sintered Ferodo pads as they seem to work well on and off road and last a sensible amount of time. Brian Eland likes the Kevlar EBC pads which apparently give loads of feel to the lever but are "softer" and he reckons they need changing probably after one rally and two trail rides as the pads are wrecked by then (could be Brian's wicked riding though!).

Fitting rear pads. Advice courtesy Brian Eland. Take the brake guard off - loosen the rear wheel spindle bolt - loosen the front bolt on the caliper body - tilt it forward - open out the brake caliper to push the piston back - take out the brake pin bolts - you should then should be able to drop the brake pads down then remove them backwards. On installation to put the pins in you have to push slightly up against the anti chatter springs, Copper Slip the brake pins very well and only tighten very carefully - if you over tighten the pin will stick and it will have to be drilled out - any doubt about the fit of an Allen key into the brake pin do not put it back in - replace it instead.

Oil filter is a common off-the-shelf Yamaha part - I used a Champion X313 last time around (Yamaha Part No is - 1UY-13440-02-00).

Can I get a bash plate and frame guards for my TTR?
Yes - CRD do them and they are available from Taylor & Sons. Unfortunately, I had a manufacturing problem on mine and it took many phone calls and a letter to Taylors, going back 4 months, before I got a replacement bracket. Also, the frame guard on the gear change side doesn't fit exactly on the older TTRs and you still end up scuffing the frame and hence the usual ugly rust - although still better than not having one fitted. :-(

Where can I get a manual?

a) The guy to contact for a manual is Gordon Brush, Customer Relations Dept, Yamaha UK, Sopwith Drive, Brooklands, Weybridge, Surrey, KT13 OUZ (Tel 01932 358000). A bound photocopy of an English manual costs £20 - make cheque payable to Yamaha Motor UK and supply your frame number. If your TTR250 is Japanese import like mine (frame number starts 4GY) then a lot of the electrics etc may be different but motor details should be pretty good. Or e-mail me for a CD ROM copy of the full workshop manual for a TTR 250 for £5 (unfortunately the scanned images are very poor but users have said its still very useful!). 
b) There is now a Haynes manual on: Yamaha Trail Bikes 1981-00 Haynes 2350, PW50/80, RT100/180, TT-R90, TT-R225, TT-R250, XT225, XT350. Available to Rides List members at a discount from Mike Husband at Merlin books - http://www.merlinbooks.com . Covers only the American spec TTR250 "play bike" though but a UK TTR owner who bought it says its still very useful. 

Wheel Bearings. The wheel bearing on the TTR250 are sealed. Replacing bearings can be a challenge until you get to know how they fit. The collars are press fit into the inner race of the bearings and you need a large drift or a press to get them out. Yamaha uses very good bearings and are worth paying the extra for. The bearings for the TTR250 rear wheel are: 60/22RS and you need 3 of them.

Rear suspension linkages. It is recommended that you take the rear suspension links apart every year and re-grease the needle bearings with good quality lithium grease. The TTR linkages are very well put together with almost all links having their own grease nipples. I stripped mine down recently - probably the first time its been apart since new (6 years ago) - and everything was in excellent condition apart from one split seal which needed replacement.

Clogging of front sprocket. It gets pretty tiresome removing the cover every time the bike gets near any dirt just to clean it out. Johnny Davies has modified the cover to allow mud etc to escape rather than build up into a nice compacted lump around the front sprocket - pictures on the Yahoo Group - address at top of page. Looks simple but effective. The Y2K TTRs have a conventional speedo driven by a front wheel cable so don't suffer with this problem!

When it all goes wrong! If anyone knows of a repair shop that has particular expertise with TTR engines please e-mail me with details.
Thanks to Terry Oram for the following: "There is a small company called Vernon Motorcycles in Havant, Portsmouth. They sell and repair all sorts of bikes mostly imports, and I have found them quite useful as most of the guys that work there have TTR250 Raids. The number is (02392)498558, It's probably worth giving them a call as they have completely stripped and rebuilt their bikes in the past." Anyone with similar personal recommendations around the globe please let me know.
And to Nik Codling: "Just thought I'd mention the excellent service I've had from Quick Crank in Waterlooville (02392 233933). This place is great - full of absolute perfectionists. They specialise mostly in restoring old vehicles, and re-building or even manufacturing things like cylinder heads and blocks." They did a good job on boring his cylinder apparently.