subanator

I came across this recently, may have been on here before. This period article and test from Mike Rapley in TMX from 1979 http://tinyurl.com/3cbz63q

A talent lost, after watching the weekend before the Phillip Island GP, Marco's podium finish shows just how good he was on his Honda amongst the factory bikes. RIP Simo.

Interesting you say that about 125's, I have been watching more of them also lately, nice to here the zing, not the drone. I reckon they have divided the classes and capacities with not too far removed from the Superbike and Supersport series. Pity, some imagination say with entry class as Twin cylinder 250's 4st, the Moto2 should be 3 cylinder 600cc 4st, and the open class MotoGP be as it is at 800 or 900cc. This would be interesting to what the manufacturers could develop, a bit of new variety to adapt to and watch.

A few of us in Oz have successfully used a method of using Molasses. This is a sugar byproduct and the coating lasts for years. But I cannot vouch for with the use of ethanol based fuels. It can be purchased cheaply at rural feed lot stores, as its used for in calfing for cattle rearing. Here is a recent topic posted on HERE

Search found HERE for you

Dont to excited just yet, there is no hidden mystery in the DT175 barrel, that is the equivalent year model 4 bolt head one. There is no real difference in porting. Fins are bigger, thats about it. Other influences between the DT and TY are making the difference. These include a bigger carb from 22 to 24 mm, the reed cage is bigger, the head is lower compression, the exhaust length is longer and tuned higher in rev range, the ignition is higher in degree advance and actually has a centrifical mechanism to advance from low setting to high. There may be differences in the airbox size, but not really a lot. Piston is the same also. Unless you are stuck for a good TY barrel, the DT is a good substitute, apart from that little else. Now if you compare the 4 bolt head barrel to the later 5 bolt head from '78 to '84 I think, there is a number of differences, but it wont just bolt on due to different base pattern. Do a search for the swingarm lengthening by Feetup, that was actually a fairly recent post about a month or so back. My Bikes - TY175C and DT175C(not running, so cant directly compare performance) (both 1976)

Interesting commentary (at our end anyway in OZ) during the race commentator and ex GP rider Daryl Beattie, says the gap of the back markers now is too big, some good ex 250 World Champs are in this mix and seem to be struggling with MotoGP 800cc bikes, and this gap would worsen when going out further to the new class of 1000cc. I remember this was also the same for the 500cc bike in their day, the back markers struggled taming those animals and were constantly being lapped by the leads riders. What happens here for Moto2 riders coming up to MotoGP next year will be a bigger learning curve than it is now. I hope they dont mess with the formula too much, as the hole will get bigger, and looking at the number of riders qualifying now, that number is quite low in rider numbers per race as to a few years ago, as is the number of manufacturers still involved in MotoGP. 2012 will be interesting thats for sure. During the race, good to see Dougie Lampkin got a mention whilst in the pits!

See HEREand download either section 3 PDF that relates to the engine, or the rest also for ref. Page 93 is what you want to know. I saved off the Yamaha Sport the parts list, this item is the shims as: 132-11561-00-03 SHIM, CRANK (25.5-35-0.3) U. R. 132-11561-00-05 SHIM, CRANK (25.5-35-0.5) 1 136-11561-00-03 SHIM, CRANK (20-30-0.3) 136-11561-00-04 SHIM, CRANK (20-30-0.4) U. R. 136-11561-00-05 SHIM, CRANK (20-30-0.5) 136-11561-00-06 SHIM, CRANK (20-30-0.6) 136-11561-00-07 SHIM, CRANK (20-30-0.7) These part numbers may differ per country, as these are for Nth America

The comments by Mick Doohan in our papers in Oz was obviously supporting the fact he is riding a Honda, but did go to say the ease he has made in taking to the Honda in terms of being able to push the bike the way he likes, compared to riding the Ducati previously 99% and at limitation. Pity that Pedrosa is out of the fray, as his mix would have made the fight for podium places even more interesting. Yes, Stoner will get there for the Championship I think too. Yes, I am enjoying this years racing too, some new faces and second tier teams now too at the pointy end like Spies and Simo are making it not easy for the experienced ones.

Firstly for me would be the above reply, failing that, there is an alternative, not ideal, but does fit. I sourced a kick start lever off an '80's RD250 or 350 Yamaha, its way too long and will actually foul with the exhaust slightly, but more with your right leg when riding. But the pinch bolt on the spline design is far more robust in cast size to the TY one. I tried to heat bend it to shape better, but was just not quite right to kick on then. Go with the original!

I dont agree with 45deg. I made up a new set of side plates for my TY175 and used the footpegs off my Beta as a guide for new ones I bought later. They ended up something different at and angle nearer to 30deg, as I leveled from the top of the pegs and cantered them forward ever so slightly, and dropped them 1" down. Sorry I never measured the exact angle. I assume Basher that you intend to fit new pegs on an old bike? I suggest the best way is to buy the pegs firstly and measure the clearances to suit as I did. But if you are going this way from scratch, then you will need a complete set of footpegs with pins and springs etc., as there is one new classic replacement that is complete and just needs welding on. Is that what you are looking at?

Iain, have you checked the pinion on the end of the kickstart shaft has not slipped? A common problem related to the TY175 is the pinion that also locates the return spring will after time break the weld that holds its location on the shaft. Usual problem is that will not return to its proper return position and sometimes over return and smashes into the side casing, usually holing it by the pinch bolt is on the kickstart lever. The alternatives are 1. replace the shaft with a new one, Yamaha still have this part on hand, but does not have a circlip groove near the outer for a shim location against the casing (nothing to be worried about). 2. Try and reweld the pinion in its proper location position on shaft (really hard to see exactly, as a new replacement is obvious, and the old one is now a repaired spare - as I have done now!) I hope this helps you some, its symptoms are looking to be related to this common problem, hate to see you go and smash you casing also, a heads up on some info anyway if its not. Cheers Roger

The end of season race was a cracker for those that missed it. Lorenzo showed he was really the champion this year. Taking the lead of Stoner was pure ability, but do feel Stoner was held back by the limitations of his setup (too harder rear tyre spinning up?). Rossi was just had to hang on to 3rd, nothing more he could do, different set up to Lorenzo? Great challenge by Simoncelli, and place by Spies. Cat wait to next year with all the new seat changes. I see red next year, I think Rossi will still be at the pointy end, but not without some renewed competition. What do you think?

I dont know how many of you know that Mozilla Firefox as your internet browser has a built in spelling check as you type. Just right click the word to correct via selection. Another tip, dont rely on Online language converters. I was posting on the French TY forum some years ago a block of text translated by Babel Fish into French. Well the result of bad grammar and meaning lost was a huge joke on me!

Looking at my options to update also, Raptors are way to pricey. Comparable to Hebo ones, how do they rate? I like the S3 adjustment options.

I like this a lot, has some real appeal. Nice job It is a reminder to me when I raced a KLX250 back in '81 (a similar engine), before the XR Honda's hit their straps soon after with a better bike. To make mine more competitive, I modified the motor somewhat. The beauty of this engine is that its a long stroke engine, perfect for a trials application, but somewhat heavy. I know you can coax more out of the engine, I tried to square the bore up, giving it around 275cc with a Moriwaki piston from a Z1000, White Brothers exhaust and Super Trapp silencer. A cam grind also helped and failed (another story). A bigger carb was on the cards, but never got around to getting one fitted. The thing I liked about the Super Trapp silencer was when I got the bike licensed for road use, I had to pull many of the stainless rings out to quieten the bike to get it passed. It also made the engine torque a whole lot more noticeable, so open loud exhausts dont really cut it with trials, but this silencer is tune-able, a nice feature. Also the KLX had electronic ignition, something you may want to consider, correct me if I am wrong to yours having points.

Why even bother? The TY175 is lighter, shorter in height and wheelbase. Gearing is better suited etc. Just be patient and look for a good TY when one comes up, in the long run it will pay off.

I reckon it works a treat, but the low end jetting is a bit of work. It is not right off tickover and tends to hesitate. Adjustment on the air screw is at the end of its range and needs a richer pilot jet. Overall the midrange and topend is a big improvement. Havent seen the OKO 24mm carb used, but believe it performs the same, and probably better set up for trials.

I tried the RD one but not happy with the outcome. Firstly the straight length of the RD on interferes with the exhaust and your leg when riding, very off putting Secondly the pivot shaft is on the crankcase side, and needs to be angled away putting the lever to far back. So I heat bent mine to that of the TY, and ended up with it short in kick length to the TY one. The design of the RD one is better than the TY on the pivot being better and stronger than the TY's design. In the end I need an new TY one as the output shaft pinion was flogged out, so a new kicker with the assembly was my best option. Cost was weighed up to piece of mind due to holing the clutch cover previously with the old kickstart lever over-returning due to the stuffed pinion.

You want Boyesen Part No 605 for DT175.

In my experience from having a Techno to the REV3 270 which is quite a lot more responsive, where I should have bought a 200 really. To soften the power delivery, it had extra 2 base gaskets fitted (3 in total). This lowers the compression, but does raise the exhaust port. Power is a lot more smoother and controllable at low speed, just requires a bit more throttle for bigger stuff. Leave the timing standard also. Rides a bit like a 250 now really, and have left it like this even now.

Also do a search in this part of the forum, this subject has been done a few times over a couple of years. Answers to your questions are within.

I had my flywheel weight skimmed so that it was just off the large rivets that hold it to the main flywheel. But in the center it was raised to allow full thread for the puller.

Must have been one of the best MotoGP races of all time to date. For those who missed the dice in the final laps of Yamaha team mates Rossi and Lorenzo was something I havent seen since 500 GP days. To see these guy swap the lead corner after corner in the final lap was simply amazing, and it could have ended in tears if one rider took the other out, real heart in the mouth stuff. The skill level went up a notch watching this, super-human skill pushing the bikes to the limits in 40degC something heat. Whats more is Rossi, Lorenzo and Stoner are on 106 points each in the championship, some competitive racing to come for the next 7 rounds! Who's your money one for this season? I reckon Rossi just has the final say in most dices (Stoner last year), seems he can pull that rabbit out of the hat when most needed.

I think you could get away with the 24mm round slide OKO, not the flatslide. I think this can be supplied as a "trials kit" also. The bigger carb will make a difference, as I inquired about this option to OKO Aust. I havent seen one done yet or heard of any either apart from the promotional one OKO Aust did. Dont know if the low down response is sacrificed or what airslide the OKO has, but maybe its more trailbike like in setup. This is where the flatslide has it over the round slide, crisper low down response. But for non stop rules, round slide should be ok really. I have achieved this with a modified DT175 carb.