Check valves

[tricky1962]

I have bought a pair of new check valves off the UK Ebay seller. I have run my bike with them for the last 3000 miles so far. I have experienced excessive wear in the little end on the side I fitted the check valves to. However, prior to fitting the valves, I was constantly getting bubbles in air lines on that side, after fitting the new valves these have now gone.

Maybe the wear was caused by the bubbles in the line, maybe by the new check valves required too high an opening pressure or maybe I shouldn't have been so mean and bought four instead of the two for my T500.

Anyway, I have bought new little end bearing for that cylinder and time will tell.

My point is that there seems to be a fair bit of bad mouthing about these new check valves without any backup evidence of their quality. They clearly spent time and money getting these valves, in their opinion, to correct spec. for sale.

I've done 3000 miles with a possible self induced problem, but in my opinion it was a previous fault. Has anyone else bought them and what are/were their experiences.

Last time I checked they had sold 77 sets in the last 12 months so how about some feed back?

[Vintageman]

I have experienced excessive wear in the little end on the side I fitted the check valves to.

I am not sure what you mean ... can you explain another way please?


I think you should do all once so you know pressure is the same.... I assume they are accurate devices, but may not be same pressure as OEM?


The key for me is to get the old metal ferrule off without damaging tubing end. Sometimes come off easy soemtimes not. Once off a little heat and the old Banjo with check valve comes out... at least the few I have done

I think maybe cut ferrule with dremal tool etc.?

Then use a small Oetker ring clamp.... http://www.industryarea.com/Clamps-and- ... logue.html" onclick="window.open(this.href);return false;


I am still looking for a correct size clamp and asked a Mechanical Engineer at my job who uses them on some of our products for opinion and size.

[Vintageman]

I just got a 73 GT550 set of line (Paul Miller. he said they were nice and 800 miles on them. Really ). Well, they are different than the 75 GT550 one for they are reddish not clear and the end plastic step up where it goes over barb is a bluish color. Two lines were plugged (dirt/shelve grime got in spider once removed is how it looks to me).

This style the ferrule pushed back real easy but, the plastic end was brittle and both cracked even with a little heat. I think this style plastic dries up nad is why ferrule slips off but, plastic cracks. Look like Suz changed design to clear plastic later in years

I had a couple good used check valves and still put them in. I pushed the ferrule back on and it squeezed the crack together. I then mixed a little JB weld epoxy and placed over ferrule for insurance against leaks. Looks impressive! Like bubble gum stuck on it. That custom look should makes my bike more valuable

Once epoxy cures I'll fill lines with oil and perform a hanging gravity oil hold test.

So far two used sets and both maybe junk. I am going broke. Starting to fear these old bikes.

My point is that the option of buying new reproduction check valves and then having them replaced is an art I have not mastered. Either the ferrule is on too tight and if not the plastic is too brittle.

[tricky1962]

When replacing my check valves I had no problem with cracking plastic, the difference in behaviour could be down to how the lines have been stored/treated over the years.

One of my other lines has been broken in the past and fixed with a short length of rubber vacuum tubing and two jubilee clips. As the pressure is I believe, quite low in these lines ca. 4 psi, I don't think there is much risk of it blowing off under pressure

[Vintageman]

It just plastic end the cracked that goes over barb of check valve not tube length.

On the different looking plastic ( i do think it is a different composition) of the 73 GT550 for example. The plastic is brittle. I simply think it is based on it reaction to our Oxygen planet not UV rays for example or other chemical reaction. The other (clear lines/plastic end) I think is different plastic material stayed pliable when stored in out atmosphere.

Did you have a hard time getting off the Ferrule?

I have not purchased the replacement check valves off eBay for luck with used ones I test, but if the barb shape is not the same it may not fit tight . Using used Suz ones these don't seem to have changed year to years (at least the samples I have tried).

Next time I will avoid the older plastic (colored) material and cut the ferrule if on tight.

Someone get good at this can offer a service!

Or just wish those who are experienced at it just tell there technique....

[oldjapanesebikes]

Or just wish those who are experienced at it just tell there technique....

David Foxall, the fellow selling the new check valves in the UK, does supply a set of instructions with his valves - an early version of those instructions are available at this link:

http://www.oldjapanesebikes.com/mraxl_G ... ctions.pdf" onclick="window.open(this.href);return false;

I haven't bought any of his yet, but probably will at some point. I freely admit that while I have repaired oil lines by removing the ends and swapping them about to make good sets from old used sets, my ability to to this in a 'reproducible' manner has not been great. I know someone will jump in to say they have done this many times and never had a problem, but that hasn't been my experience - and as the typical owner only has the one set, then it is a high risk activity. I have had far better luck splicing known good ends into oil line sets to replace dead ends - 'how to' information is elsewhere on this board if you do a search, plus I wrote about it at this link:

http://oldjapanesebikes.com/blog/2012/0 ... ion-lines/" onclick="window.open(this.href);return false;

I'd like to believe that at some point, someone somewhere - perhaps even Suzuki - will offer reproduction new sets, but the cost of them will necessarily be high due to the low volumes they would be able to sell.

[tricky1962]

I think, as Vintageman has suggested, that without a ready supply of replacement check valves, all these two strokes will end up off the road.

The future for these bikes has to require the reproduction of essential parts that Suzuki are not prepared to manufacture including check valves.

These guys; http://www.ebay.co.uk/itm/Suzuki-T250-G ... 27e97c01fe" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false; have done exactly that and put in a fair amount of cash for their development I would imagine.

I think it would help the confidence of potential purchasers, and presumably the suppliers themselves if there was some feedback on this product. I looked and couldn't find any.

For the record, again, I bought them, they turned up promptly and were easy to fit. I have suffered wear to a little end bearing on the side I fitted these valves, but I am not currently attributing that failure to these valves - for more detail, I started a thread "holed piston".

So.. currently 77 purchases this year so far, does anyone else have feedback?

[Vintageman]

oldjapanesebikes

Thanks so much there is some good info there . Your efforts to this cause agian deserve much thanks and is impressive-respect

I did not dare to put the ends in my vice for did not want to damage surface. I need a better vise with smooth/soft jaws.
I used a bolt, couple washer, nuts and placed one bolt end in vise resting banjo close to jaw on the side and held the other end at times while I worked one hand to prise thing off (small thin screw driver ). The dikes or two sides tool is a better idea.


he says collet usually comes of easy. I have seen both cases. But sharp thin two sided prise tool that cut into plastic first neetly may work better

Once off a little heat (in my case I used hair dryer) I could usually get hose off.

But. the 73 GT550 lines the plastic (blueish end) was brittle and cracked. Maybe I rocked on angle a little but will say it split right off I don't think don't think smaller diameter would go over the barb without splitting on that design and would not try again even with new tool. But the oil line design varies from Suz or at least the material used. Need to pick the better ones is my advice

I received a set today from a 75 GT550 . It was in a grab bag of loose misc parts and I got all for $20.00 shipped. This one is perfect and doesn't leak either

I have $130 invested for bought those two used GT550 73 lines first (my bike 73, but all years same plumbing)

I am not sure what Suz would charge for new. You have said this before. If enough people asked Suz they will make again. Really ! Have you seen this happen?

tricky1962,

I think the only risk with the eBay ones is if the barbs is not the same design. For the plastic end is shaped like a key from being molded about the original check valve's barb. So if the others not the same then mabye a sealing issue? Just a concern

Next I would change all just to be sure they crack open at the same pressure point ( i supposes it depends on pump design and think some say for example the GT750 style has more than one pump (do homework)... look at oldjapanesebikes website information.

The twins use just one pump so here would be four.

Thanks!