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canada280i

Ty 80 Engine Questions/help

19 posts in this topic

Goudrons and Charlyxty were kind enough to offer assistance with my electrical questions for my recent TY80 purchase. I stripped the side cases off the motor tonight and now have more engine related questions I am hoping someone can answer:

1: Can the gear shift shaft be replaced without splitting the cases? it looks like it just pulls right through from the clutch side (I hope so, the previous owner sheared the splnes off the end of the shaft with vise grips)

2: when I pulled the clutch case I noticed that one of the basket side pieces is snapped off. I will look for a replacement but if Ican;t get one will it still work okay? when I bought the bike the engine was out so I have no idea if it ran like this before.

Apart from these two questions the insides look very clean, no oil leaks, gear select okay (apart from the knackered shaft), stator sparks like crazy.

Daughter seems eager for me to get it fixed for her so thats another good thing.

Ebay here I come for the bits.

Any advice on the above will be greatly appreciated!

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1, Yes. http://www.tytrials.co.uk/trailandtrialsuk/cat_43333--7-Shifter-2-Gear-Lever.html

First,

Remove the gear lever, remove the left hand cover.

Prise the circlip off the left hand end of shaft (4) and remove the washer (13).

Working from the over side of the engine, remove the clutch.

Behind is the selector claw (1)

Prise off the claw retaining circlip (the other 4)

Press the claw down and lift away.

Remove the roller (7) and pull the shaft (8) out.

2, Someone has tried to jam the clutch basket with a screwdriver or something to undo the nut and broken the basket.

There is a flywheel/clutch tool that saves this

http://www.tytrials.co.uk/trailandtrialsuk/prod_424514-Clutch-amp-Flywheel-Holding-Tool.html

It should work with one missing, but it may not feel right.

Check the inner edges of these pieces of the basket, they get damaged by the plates rubbing on them, you can often file then flat again to make the clutch action smoother as the plates will run against them without sticking, also the clutch rod can get bent causing a stiff clutch that kids won't be able to operate.

There is a kit to refurb this

http://www.tytrials.co.uk/trailandtrialsuk/prod_147748-1626-Clutch-Arm-Repair-Kit-TY80.html

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Firstly, this is why I love this site! This is a great help to me and gives me the confidence to keep going with this project, thanks Goudrons!

I wa looking at some of the ebay links and they reference that the parts also fit a YZ80, is the basic engine the same in a YZ80 as the TY80? if so, this will probably help me more as YZ motocross parts will be easier to source than TY parts here in Canada, especially thngs like gasket and seal kits. If this is the case, do you know up to what year are they similar? for example, would a gasket set for a 1977 YZ80 fit a 1974 TY80, or would it only be a 1974 YZ the same as a 1974 TY?

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Hi Goudrons....one more question I am hoping you can answer for me. I looked up the engine number (2G9-200983) which appears to correspond to a 1978 Yamaha GT80 (Canadian model), do you knwo if this engine is the same in terms of parts? Also, will it therefore be geared wrong for trials or is this controlled by sprocket sizes. The frame and everything else that came with it are definitelky TY80 but if the engine is not going to be any good for trials I dont want to waste money on the repairs.

Thanks!

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I'm not up with what parts are fitted to which.

You can cross reference parts here

http://www.cmsnl.com/yamaha-motorcycle_model16707/

A quick look and transmission seems to have the same part numbers, as does the crankcase halves and so on.

I'd say the GT80 was the same engine apart from the stator, as you've found out, it has a lighting coil and the TY doesn't.

Methinks there will be similar shared parts with the DT50, RD60, GT80 and probably a load of others.

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Thanks Goudrons, you have been a great help, it is very much appreciated!

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So, just an update on where this project currently sits, I had to buy a new kickstart assembly ($40), new shift shaft ($40), nerw shift lever ($20), and a new kickstart shaft seal ($10), all sourced of e-bay. Unfortunately it turns out that some of the engine parts between a TY80 and a GT 80 are different which meant that the shift shaft was the wrong size so i had to get another for another $30, still, I will relist the NOS TY 80 one that I orginally bought to offset some of the cost. I thought I had everything covered last night and was getting excited to be entering the final gasket making phase before putting it all back together when I discoverd that the oil pump gear was missing, likely broken and removed at some point. A quick browse around e-bay and a complete new pump assembly, gear, shaft, and related hoses was ordered for the princely sum of $13 + shipping ($25) total, so I was very happy with that. Onve it arrives I will reassemble and hope that it starts with little or no effort.......fingers crossed!

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I remember something about removing/disabling the oil pump and running the bike on premixed oil/fuel but that was over 30 years ago on my TY80.I just cant remember whyI think maybe it used to over oil ?

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I toyed with going that way as well but had more difficulty finding a right size single throttle cable to replace the double oil pump/carb cable that came with the bike so the pump gear replacement was the cheapest option. If it fails again I will certainly be removing the pump and going the premix way.

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You can remove the oil pump part of the cable from the junction box and just run straight to carb.

And Venhill make several cables for these, standard twist grip with oil pump, standard without, amal twist and so on.

http://www.tytrials.co.uk/trailandtrialsuk/cat_43346-20-Handlebars-Cables.html

The oil pimps got removed as they never worked properly, a pain to set up and if they went wrong, major damage would occur!

If you do run on pre mix, don't forget to bung up the oil feed on the inlet (me thinks it's on top of the inlet manifold)

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Problem solved!

I picked up a second complete TY80 and made one good bike out of the two, so now I have a complete TY80 working for my daughter, and a spare rolling chassis and GT80 complete engine that I will probably sell as a project to someone for a couple of hunded dollars.

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did you get a manual from your other post? I have a PDF of manual and PDF of parts lists

gasket sets and many parts from Dennis Kirk.com Veshrah gasket sets from TY were available, but not listed, last time I bought was several years back. from YZ and GT fit and were about $10 US, but I think the head gasket had to be punched out for bolt holes.

Oil pump, yes, remove it completely with gear. Build your own cable with a generic housing (Dennis Kirk also) and a bicycle shifter cable inner wire. That is quite a bit softer and more flexible, and easier for daughter to use.

GT80 is similar I think the cases were wider on one side so shifter is different. Heads were different, one used nuts, one used cap nuts deep into the cylinder. Some GT80 has 5 speed transm, but no advantage to change. The ratios all the same, just a higher gear on top. TY issue was the gap between gears, not the overall ratio, so the 5 speed would not help.

I had several TY80 as kids grew. sold off my remaining TY80 stuff this winter as my daughter is now 23 and in law school, middle son 25 and rode some nationals a few years back. My how they grow.

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Kevin

Would like a copy of the manual. Working on a rebuild of my son's Whitehawk 80, for a grandson.

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