Trials bike noob needs help

[ktm84mxc]

You'll find body language and position will play a part in making the ride easier , most trials riders can bunny hop like a BMX/skateboarder so get practicing over kerbs etc.
had a mate who would wheelie his TL125 the length of Muriwai beach at low tide did it standing by weight transfer.

[Night Falcon]

Changed the oil and flushed the crank out with kero, put it all back together and new oil. started up fine but has a rattle coming fom the engine thought it might be the clutch so pulled it out and cleaned it up and put back together. took carb off and cleaned it out. Exhast still had some water in it but I think it's from the muffler packing. so will replace that. The air box took some removing as 2 of the screws were rusted tight so had to drill them out to remove it . will be doing a mod to make sure that dosn't happen again!

I can't beleive there is anything serious gone wrong in the motor and don't think it has hydrauliced the engine? Anyway, wont know till the air box is fixed and shes all back together. The rattle sounds like shaking a stone in tin cup so don't know what thats about?? Once I get it back togheter I'll see if the clutch clean fixed the problem....other than that it migh be a trip to the shop. Any one have any ideas to ease my worried mind?

[NordieBoy]

Can you hydraulic a 2 stroke?

[gwynfryn]

If the gearbox had water in it the oil would go milky, i guess some water could come in through a breather hose . Are you sure its not pink because its automatic trans fluid.
How did you flush out the crankcase ? Did you tip it upside down?
Sure you are not getting the 2st 4st thing mixed up?

[ktm84mxc]

Yes you can hydraulic a 2 smoke have seen it on a PW80 when little Jonny filled the engine while washing it, kick start wouldn't move . Ask a jet ski mechanic about bent conrods and twisted/smashed pistons from drowned engines.
Have used ATF in my VMX KTM and the only way it would turn pink is with water, either through the breather or leaking water pump seal.

[Night Falcon]

If the gearbox had water in it the oil would go milky, i guess some water could come in through a breather hose . Are you sure its not pink because its automatic trans fluid.
How did you flush out the crankcase ? Did you tip it upside down?
Sure you are not getting the 2st 4st thing mixed up?

The replaced oil turned pink also so that explains it so maybe thats ok. Didn't tip it upside down, just put the bung in and put 1/2 ltr of kero in it, took plug out and kicked it over a few times, left it for 10mins and drained. seemed to clear it out ok. there was a small amount of metal filings on the magnetic sump plug but thats not uncommon..... but then could be something or nothing?

Yes you can hydraulic a 2 smoke have seen it on a PW80 when little Jonny filled the engine while washing it, kick start wouldn't move . Ask a jet ski mechanic about bent conrods and twisted/smashed pistons from drowned engines.
Have used ATF in my VMX KTM and the only way it would turn pink is with water, either through the breather or leaking water pump seal.

I imagine if the engine had hydro'd it would be pretty apparant? It starts ok though just has this rattle sound? Its pretty easy bike to work on so am going over every nut and bolt to check tightness...and some were quite loose. Thought it might be a stone trapped between the alloy sump guard and engine but couldn't find anything.

[gwynfryn]

You are not flushing out the crankcase then, just the gearbox.

[Night Falcon]

You are not flushing out the crankcase then, just the gearbox.

cleaned out the crank tonight aided by a mate who was quite a good mechanic back in the day, even learnt a few tricks and got refresher course in 2T mechanics. put her back toghether and started 2nd kick . the rattle was still there but seemed to run fine. We had a good listen to the all parts of the engine using the tried and proven "screw driver stethoscope" method and couldn't find any obvious problems. My mate reckons it sounds like a normal rattly 2 smoker but I'm still not convinced theres not something amiss. Any way will test her out in the weekend; if she stops suddenly I'll know I was right

[ktm84mxc]

Had a similar noise on my VMX KTM the rattle would rise when the engine was revved , turned out to be the needle bearing on the crank . It would start and run ok just an annoying rattle, was glad to find it in time the head was pock marked but ok a new piston and conrod kit good to go.

[Night Falcon]

Had a similar noise on my VMX KTM the rattle would rise when the engine was revved , turned out to be the needle bearing on the crank . It would start and run ok just an annoying rattle, was glad to find it in time the head was pock marked but ok a new piston and conrod kit good to go.

Yeah I reckon you might just have called it. Funny how your mind starts playing tricks trying to remember if it always sounded like that or not.....but I think definaetly not. On the plus side I almost enjoy working on it more than riding it so all good in the hood.....gasget set and new bearing and shes good to go!

Thanks for your comments

[Night Falcon]

Found the cause of my rattle, both main crank bearings are poked! Seems they are EXTREMELY sensative to any contact with moisture. Also discovered two fangs missing of the main gear next to the kick starter but managed to recover both wanderers.

My guess is the water in the crank case has hydroliced the engine forcing the teeth to sheer of the starter gear (weakest link) whilst being kicked in the guts by my size 10 alpine stars

anywho...reasonably fun day in the garage pulling it to bits and straight forward to fix. Although there was zero play in the conrod bearings and barrel is fine I will replace both bearings, piston and rings while I'm at it.

[Ocean1]

Found the cause of my rattle, both main crank bearings are poked! Seems they are EXTREMELY sensative to any contact with moisture. Also discovered two fangs missing of the main gear next to the kick starter but managed to recover both wanderers.

My guess is the water in the crank case has hydroliced the engine forcing the teeth to sheer of the starter gear (weakest link) whilst being kicked in the guts by my size 10 alpine stars

anywho...reasonably fun day in the garage pulling it to bits and straight forward to fix. Although there was zero play in the conrod bearings and barrel is fine I will replace both bearings, piston and rings while I'm at it.

I'm not sure that it's very likely you hydraulic'd it while kicking it.

Still, now you'll know it's right, eh?

[F5 Dave]

golly, heat treating must have been naff. Never ever seen teeth broken off gears like that.

C3 clearance on main bearings. heat cases to get them out, freezer bearings to get them in.

[Night Falcon]

I'm not sure that it's very likely you hydraulic'd it while kicking it.

Still, now you'll know it's right, eh?

yup, not too worried as least I now have a clean slate in terms of where the engine is at.

golly, heat treating must have been naff. Never ever seen teeth broken off gears like that.

C3 clearance on main bearings. heat cases to get them out, freezer bearings to get them in.

judging by the wear on the bearings and conrod I'm thinking this isn't the first time this bike has been immersed in H2o over its aledged 160hr life span

[NordieBoy]

160 hrs?

Should be due for a cam chain and rings by now...