Suzuki 2 Strokes

So there's lots of info here on their pistons, but has anyone used their crank seals? I haven't priced out the genuine Suzuki ones yet (and if they are anyone close in price they would be the obvious option), but was intrigued by the price for the crusinimage set of seals.

Thoughts?

Buy the oem ones from Suzuki, its not worth the possible hassle you may encounter.

That was the direction I was leaning in.

Ordered a set of suzuki crank and transmission seals. For anyone thats curious the price for all of it was $130 in 2016 Canadian dollars.

Agree with Allan. A crank rebuild isn't something you wanna do once. Let alone, twice.

Agreed.

Here's a couple pictures of my RD350LC piston when it blew a crank seal and started sucking air. Warning, its not pretty. You'll have to excuse the poor image quality, I didn't have a good camera at the time.

This fell out of the exhaust pipe when I took it off


When I pulled the head I was greeted with this


and then this


These were the biggest pieces I could find of the piston......



So yeah, thats why I'm rebuilding the crank with new seals before even trying it....

dude99 wrote:it blew a crank seal and started sucking air.

Did you also take a picture of that seal you can show to see how bad it was?

I have run many engines with marginal to wasted crank seals. I have re-used old seals and I have replaced. It's all about how much in a hurry I am and mainly how good the crank is mechanically. If decide to re-use I am not expecting problems and so far so good. For me its bearings/rods that worry me the most and if in doubt I change these and then seals get changed at that point regardless. I try to get fresh OEM and stay away from old stock that has been setting on shelf unwrapped if possible. Same with old piston if they look "aged" I change. Else it seams to me they fail at skirts or eroded hole on top where plug is much faster than a fresh young piston would in its place. The next two things that freak me out is to make sure I am jetted correctly (fresh new OEM brass everywhere and always) and indeed the oiling system works. That should be check often. If ride hard I add a little oil in gas tank as premix. It also has saved my engine if something fails with oil system

Yes it's not cool to blow engines...

Did you also take a picture of that seal you can show to see how bad it was?

Indeed I did



I will never own a two stroke again that I don't replace the seals in....

Yup that is bad. How was the crank bearing? I have had that occur when the bearing goes bad and then seal goes due to slop in shaft and heat of friction (looks like the may be case hear maybe).

If the shaft has even a little movement that event can occur real fast once the bearing fails worse and voila melt down.

My point is sometimes the seals alone get a bad wrap when it is other items. Not that a seal can't go bad, I just find it more the case the crank had a mechanical issue as the root cause. Easy to check that in advance. Easy to test aif seal OK too. Oil pump or fee line can be root cause as well. Yup, sucks to blow and engine

I don't recall the bearing being bad, but I didn't really look at it that closely to be honest. But since to inspect the bearings you need to pull the crank anyways, new seals are cheap insureance.

You reply before i post? LOL

I also find crank bearing are wise things to change too... if any play or gritty. Look race and roller balls if you see wear or shinning spots like they have been running like a train wheel on tracks . And BE for rod (side to side rock test is a good sanity check) Again if bearing goes bad you are screwed too. Better to change that up front if in doubt or just to be proactive. (how many miles on engine is an other driving point it is time to change to be proactive)

fun stuff

Indeed. I have 2 cranks so I'm hoping my machinist (who also owns a water buffalo) can build me a good one out of the two. The full set of crank bearings is quite expensive, so if I can avoid that I will. But if it needs to be done of course I will.

dude99,

I don't trust anybody telling me my bearing etc. are good anymore. I don't think people always take the time to really check. If you believe they do you have more "Faith" than this bitter old man. You need to check yourself best you can what you can. I know it's expensive and have used faith myself to save money and worked out OK.

Same with BE and PIN. I change that now regardless. I think on the GT750 I used a BE bearing from RMX250 which allegedly is better. But don't recall for sure

The T350 crank I just had done I changed EVERYTHING rods, BE, Pin and ball bearings accept middle bearing. Not typical i do this but had bad luck lately revving those up up.

One thing I have seen with Suz two strokes cranks. If the bearing is oiled from crankcase oil it shows much much less sings of wear than the ones oiled from injection line . You see Paul Miller claim when he refreshes a crank with new seals it is low miled one to start. If it is that is real good thing

Last year I was lucky and got a GT250 crank with under 2000 miles. When I got it I could see how nice it was versus the one I pulled with around 12K if I recall. And no way did I bother to change seals ( a little ATP-205 or blue devils helps). I just dropped that beauty in and so far no worries and smooth (less vibration than one I changed)
I am boarded so just shooting the bird so to speak.

I think the GT750 crank is tough to start but seals were not. The little Suz twins are not over designed so wise to refresh all IMO. The Yam cranks get a lot of stress and those need to be refreshed more often of just new aftermarket crank may be wiser, lucky to have that option.

Good night

Yeah I just replaced the crank in the RD with a new one from the UK, I think it was $500 shipped to my door. Normally I would;t trust anything a shop says, but my machinist is different. He's been building two stroke cranks and other motorcycle stuff since the dawn of time. He also runs his own little shop, just him, off of his property. He takes his time and does things very well... I have trust in him... Probably the only "professional" left I do trust.

We'll see how it goes. Hopefully I'll pull the crank out this weekend and see what I have. I picked up the seals from the dealership today and will hopefully drop by the machinist on Thursday.