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Messages - AndyD
16
« on: September 04, 2024, 05:28:19 PM »
Another technology fail with posting - this time only one picture appeared!
Hope these appear this time - finished (again) bike and pattern seal with missing oil passageway
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17
« on: September 04, 2024, 05:14:47 PM »
All done!!
Thanks again for help and advice on getting this done.
Enjoy your holiday Dave, managed to lift the engine back in and it wasn't too bad in the end - it's more awkward than heavy to get wiggled into the frame.
Not bad with the 250, not sure I'd try with anything bigger any more!
All back together and polished back up.
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Interesting on the seal as I bought an original Honda one (as used in the first build) but also a pattern one from eBay out of interest.
The pattern one is nothing like the original and has no locating lug and worse has no holes for the oil passage in the casing - photos shows the differences.
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Pattern seal would be easier to replace without splitting the cases but clearly wouldn't be right - I wonder how critical that oil passage is and how many engines now have this blanked off.
Cheers,
Andy
18
« on: September 04, 2024, 03:50:52 PM »
Thanks,
Had another really close look (even put the reading glasses on) but couldn't see any matching dot.
I've had a good play with it and set it where I think it 'feels' right in terms of operating the decompressor mechanism - it's one of those assemblies where it's really not obvious how it all works but slowly becomes clearer after a good study and multiple trial assemblies.
With the cover back on it now at least does something that looks 'right' when the kickstarter is pushed so hopefully once I get a couple of other bits done I'll get a chance to see if it works as designed.
It's a nice, relatively simple bike to work on generally - although as with seemingly all old bikes getting the carb on or off is a royal pain and that's next on the list!
Cheers,
Andy
19
« on: September 04, 2024, 10:57:26 AM »
Apologies for the repeated image - had problems with site crashing half way through typing and seem to have clicked a few extra buttons somewhere!
20
« on: September 04, 2024, 10:41:41 AM »
Thanks guys,
You’re right Bryan, Yamaha seem to use dots for alignment throughout the engine which is quite neat, however on the kickstart assembly I couldn’t see any matching mark for the two parts of this.
Hopefully the photos shows the assembly clearly – the front ‘lug’ position is what I’m trying to clarify as it sets where the decompressor activator sits. This is a pivoting part that uses a cable to hold the exhaust valve open during starting. The rear lug locates into a holder in the crankcase so moving the relative positions front and back is what sets the position for the decompressor action.
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The gear spins on the spindle with the front and back parts able to be positioned by moving positions on the splined shaft. There is a clear dot on the front lug but I can’t find anything on the rear part of decompressor spindle / crankcase etc. etc.
I can’t find anything in the Yamaha or Clymer manual about the setting and the photos are not very clear so I’m a bit wary of basing it on these.
I hoped to find a photo of this somewhere on Google but have failed so far.
The engine has had a tough life and been subject to many (poor) repairs and ‘alternative’ assembly methods so it’s likely the kickstart / decompressor has been put together wrong in the past.
If I can’t find anything conclusive I guess I’ll have to try different configurations to see what could work but I don’t want to keep taking the circlip off the assembly in case it starts getting looser etc.
Cheers,
Andy
21
« on: September 03, 2024, 08:07:55 PM »
Hi,
Hoping maybe someone can help with a query on my 1980 Yamaha XT250.
Had problems with the decompression mechanism and I think it's down to the kickstarter assembly and the relative position of the 'lug' on the starter assembly.
Hoping someone may have a photo or knowledge of where the lug on the assembly should be positioned - I think the existing as shown in the photo is incorrect but can't find any reference to correct assembly in manuals or online.
Position is adjustable b taking apart the assembly so I'm guessing it's been put together wrong in the past (the engine had signs of many bodges and damage so no surprise!).
Hope that makes some kind of sense!
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Cheers,
Andy
22
« on: August 20, 2024, 01:45:31 PM »
Agreed about the cost - shame they don't do a really small tube for us 'once-every-now-and-then' mechanics!
I've had the Threebond 1215 tube for quite a few years and it was only last time that the contents had started to separate a bit inside the tube so had to squeeze some out before getting to the good bit.
Still seemed to work fine but guess it's time for some new gloop.
Looking at the Threebond website and Googling doesn't really help that much so I think I'll just stick with getting the 1215 stuff.
Cheers,
Andy
23
« on: August 20, 2024, 10:15:23 AM »
Thanks guys,
Think I'll get the 1215 Threebond as it seemed fine in the past and is readily available (and grey).
I just wasn't sure if there was some reason the Hondabond HT was needed / preferred for any reason rather than the 1215.
Cheers,
Andy
24
« on: August 19, 2024, 05:47:25 PM »
Hi,
Looking to get a fresh tube of crankcase sealant and wondered if anyone had views on best stuff.
Have used Threebond 1215 previously and works well, and is also grey which works well with unpainted engines.
Seen a lot of Hondabond HT too which is black but presumably for higher temperatures as name suggests?
Any views welcome before Googleshop and order something up.
Cheers,
Andy
25
« on: August 18, 2024, 05:57:45 PM »
Thanks Bryan,
It was in the Honda workshop manual and just sounded too good to be true!
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Didn't want to risk anything so I took off the clutch and oil filter so everything was clear on the case joint - definitely needed as the gear change mechanism spans the case joint and would have been tricky to get cases apart and likely impossible to refit later.
With a bit of playing around with bench lift / small engine jacks etc. managed to get the engine out quite easily and without damage so that was a relief - don't think getting it back in will be so easy so may well see if Dave is still happy to help at that stage!
Cases came apart easily so just sorting a list of parts needed and will get these on order next day or two and then get ready for the next instalment.
Cheers,
Andy
26
« on: August 18, 2024, 11:07:02 AM »
Finally getting enough renewed enthusiasm to replace the seal and running through the manual it says you can simply remove the bottom case without touching the clutch / oil pump and filter etc.
Sounds great and hopefully correct but looking at photos of the original build I'm wondering if this is possible as the gearchange bits straddle the case joint and sit behind the clutch.
Hope someone can confirm - manual option obviously saves time and effort but don't want to try it and find bits getting caught up when cases come apart.
Cheers,
Andy
27
« on: July 09, 2024, 12:33:53 PM »
Thanks Dave,
I'm just thinking if I'll need to order any other bits beyond the oil seal for this.
If only going in from the underside (i.e top end untouched) I'm hoping the other oil seals etc. affected when splitting the crankcases can just be retained.
I'll have a study of the parts drawings and photos to see what could be affected.
Cheers,
Andy
28
« on: July 08, 2024, 05:29:12 PM »
Thanks Dave,
I may well take you up on the offer if that's OK - always fiddly getting the lump in and out without damaging all the shiny stuff!
I'll get the bits needed and try and formulate some kind of plan.
Cheers,
Andy
29
« on: July 07, 2024, 02:56:55 PM »
Many thanks Bryan,
That should save a lot of grief (and cost) hopefully.
Just have to summon up the enthusiasm to drop the engine out and get on with it.
Cheers,
Andy
30
« on: July 07, 2024, 02:06:39 PM »
Thanks Dave,
Guess I'm pretty well resigned to having to strip her down again although I may put it off a while to rebuild some enthusiasm.
Was hoping to finally get some riding in this last few weeks and even bought a new helmet and gloves thinking the 250 would be ideal for start - best laid plans and all that!
Like you I'd seen a few stories of replaced seals without dismantling but doesn't really sound right somehow and always best to do it right.
I can't recall if it's possible to split the cases without stripping the top end at least saving a few gaskets and jobs! Will have to have a look at that and see what makes sense.
In the meantime must get busy with clearing some space in the garage and sheds - too many bikes / projects / spares and waning enthusiasm so think it's really about time for decisions on what to keep and what to get rid of.
Cheers,
Andy
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