A look at the 2.5 Innards - DIY 20K mile service, including valve clearance check and shim replacement

[Journeyman]

So are you putting the exhaust cams back in to check those clearances before reassembly in case they are out of spec. It would worry the crap out of me wondering what the clearance on those exhaust valves were. Seems like a good time to check those again.

Oh, yeah- waiting on the tool I need before moving forward. I'll check those and all of the others one more time.

 

[Journeyman]

Me wonders if those decompressors are as accurate as the cam lobes. They don't look it to me as if each one could have different clearances depending on the opening travel arc.

I'm no expert- just learned what the he11 they are, but I think they simply provide "some" extra space at startup to reduce the compression. The exact amount isn't crucial for that. Then they get spun out of the way and it's just the cams controlling the openings after the first revolution.

 

[wjb]

The decompressors that Triumph put on the Thunderbird twin has been a real problem area for that engine.

 

[TURBO200R4]

The decompressors that Triumph put on the Thunderbird twin has been a real problem area for that engine.

can you explain?

 

[wjb]

They seem to have a habit of coming apart. The Thunderbird 1600 and 1700 engines have earned a reputation for failures in that area.

 

[Gregger]

They seem to have a habit of coming apart. The Thunderbird 1600 and 1700 engines have earned a reputation for failures in that area.

I just read that complete thread. You wonder if this was one of the reasons Triumph dropped the line. What a lot of crap on their part. Even the replacement cams came broken. I would of removed the decompressor completely and run without. From what one of the posters stated, he did this and had no issues starting even in cold weather. Just need a good battery.

Don't you hate it when the manufacturer uses good paying, loyal customers as guinea pigs.... shame on Triumph!!!

 

[Journeyman]

I just read that complete thread. You wonder if this was one of the reasons Triumph dropped the line. What a lot of crap on their part. Even the replacement cams came broken. I would of removed the decompressor completely and run without. From what one of the posters stated, he did this and had no issues starting even in cold weather. Just need a good battery.

Don't you hate it when the manufacturer uses good paying, loyal customers as guinea pigs.... shame on Triumph!!!

I'd be easy to remove them- just one screw, I believe, and tempting, but I'd hate to put it all back together and not be able to crank it. It's a dilemma....

 

[cootertwo]

Seems to me, it would have been much cheaper, for Triumph to just use a bigger starter, rather than go to all that design cwap, and way too many little pieces to break.

 

[TURBO200R4]

I'd be easy to remove them- just one screw, I believe, and tempting, but I'd hate to put it all back together and not be able to crank it. It's a dilemma....

I would leave them them out or maybe just install one and cut the odds by two thirds

 

[Journeyman]

That one shim that you always need, but have all the others, is coming today. Hoping to be back on this project later this afternoon. The cam chain tensioner tool came earlier and I now have a better understanding of how it works. It puts a very specific tension on the chain while the cams are in the proper position while at TDC. Then you tighten down the sprockets on the cams while in that position for exact timing. This IS an improvement over the 2.3s. More to come as I, hopefully, start to button her up. Just hoping I can remember where everything goes .....