TrxPipUK

I have a new cam chain but no right side gasket

Yeah hahah

Ah that's good to know! I'll be getting a compressor anyway to put the valves back in. I don't trust myself not to break something with the hammer and socket method lol.. So I'll wait for the compressor lol 🙂 Thanks for the tip shade

Well I haven't made much progress since I took the piston off the rod really. I'd like to measure the I.D. of the top end of the rod but don't have an accurate enough vernia caliper or other tool to do it. I measured the wrist pin and and that has a O.D. of 21.01 mm, the service limit is 20.96mm so that's looking good. I'm also waiting on a valve spring compressor so I can get those valves out and clean them up.

Thanks @retro 🙂 I've been checking out the manual and found these measurements. What does it mean by 'piston-to-piston pin clearance and how do I calculate it? I'll do the other measurements and get back to you 🙂 Thanks

Ah okay, makes sense lol... So how much 'wiggle' is acceptable for the wrist pin? Not really sure what I'm looking for haha. Did you see the video I linked for the bottom end test?

Yes I put the wrist pin into the rod as pictured. Then holding the long end I wriggled it up and down. What is a cause for the rod to be in bad shape? Just general use or what? Thanks man

So been to the workshop and tested the rod on both ends. There is the tiniest amount of play at the top end, like a very minimal amount. At the bottom end there is a little bit of play side-to-side but none up and down. Video of bottom end test^^^

Thanks man! Yeah it's great to learn this stuff I think... especially about a machine I'll be using lots once its running. Just gotta keep saving the £$£$ lol. Thanks for your help as always man

Thanks @retro. I'll try getting those circlips off today and get the piston off. I'll get some pics of testing the rod as well. Thanks again man 🙂

@retro and @shadetree thankyou!! I can't thank you enough for your help. Don't worry, I stuffed rags down there as soon as those pics were taken and when the cylinder was removed. So next step is to remove the wrist pin and check out the rod. What kind of movement am I looking for on the rod and where abouts should I be looking? It's a shame about that piston. But oh well, guess it couldn't of been helped. I'll try and find a motorcycle or ATV mechanics shop and take the piston and cylinder over. Would I be looking to get a new piston and the cylinder bored out then?

Awesome thanks guys. Just been out and wiped down the oil off the cylinder. Got some pics to show you lot as well 🙂 The piston rings definitely aren't free moving. They were all stuck snug in the piston, I started pushing and poking the rings and one popped out. You can see this in the pictures. I looked at taking the piston off the rod but I can't see how you do it? Is there a special way to get the circlips off to get the wrist pin out? Thanks

Yeah I reckon a top end kit is the way forward. Not sure what it's like getting them over here in the UK though 🤔. Just to check I understand the meaning of a "top end kit"... You mean like new gaskets, piston rings and piston?

@shadetree and @F250 guy yeah think it might be mostly rust and a bit dirt. When I got the quad it didn't have a spark plug in so I presume moisture was let in that way. 😬

I never got round to doing the wet compression test actually lol. Not a great sign that oil is there then? I'll get some more pics tomorrow 🙂 What are the piston skirts?

Here's the inside of the cylinder as I pull edit off the piston. A fair bit of oil. Is it meant to look like this?

Right, so I wasn't sure what angles ect to take the pics, but here they are. Gonna take some measurements at some point as shown in the manual. Let me know what you think 🙂

Okay that's good to hear lol. Not planning on replacing the O-rings no. I'll get some pics later on once I've finished some jobs on the farm. Thanks shade

Great thanks for that advice on removing the cylinder. To inspect the rocker arms do I need to remove them from the rocker box cover?

Ah okay. So the Mark's should be perfect really. How do you go about adjusting the timing? Is it just a case of taking the chain off, lining all the marks up then putting the chain back on?

Yeah I was thinking along these lines. I'll pull the cylinder and check how things look there then decide on a bore and new piston kit. I'll get the cam chain changed out as well. I can see what you mean the marks aren't quite lined up. I'll get the valves out once I have a spring compressor. Thanks shade. I'm quite enjoying it actually lol... Good to learn about these things 🙂

I'll get some measurements and pictures of those and report back. But to my eye everything looks to be in good shape with them. The left side header pipe had a huge crack in and has been brazed back up. No holes. 🙂

Yeah it definitely looks that way. New rings and possibly a bore are on the cards.

UPDATE: Today I started looking into the engine and taking her apart. I checked the timing and to me it looked pretty good. The chain seemed to be a decent tension and not slack, but the tensioner was fully extended. I'll replace it anyway I reckon. After that, I removed the rocker box and looked at the underside of the valves (still need to get a valve spring compressor) and the top of the piston. Wondering if it's worth taking off the cylinder and seeing what state it's in considering there was such low compression? Also replacing the rings and maybe the piston? Would be great to hear your thoughts, thanks 🙂

Thanks man for the information, extremely helpful and appreciated. All this is gonna be a real big learning step in mechanics for me haha. Looking forward to it though 😁