tm125 oil pump query

[suzuki447]

gday ,can someone tell me if i can disconnect the oil pump and run premix.and how i go about it .thanks don

[John Orchard]

Those early Suzuki's had CCI (Cylinder & Crankshaft Injection) lubrication.  One oil line goes to the inlet manifold, one goes to the left side main crankshaft bearing (the right crank bearing is lubed by the gearbox oil).

You can run pre-mix but for best left side bearing life you must split the cases and trim a tin cover that shields the bearing oil being diluted by the fuel charge.

I always ran my TS's & TM's on pre-mix, once you've trimmed the bearing cover, just ditch the oil pump & lines (make sure you block them off though).

[bazza]

easy, did it to my sons TM.Cant remember 100% but easy at the time,TM experts here will give you info.If not PM me TM guru here in unzud will know how

[brent j]

My two cents worth.

Remove the oil slinger on the crank and replace it with a shim of the same thickness or cut the outer part of the shield away, remove the half shield in the LHS main bearing and drill a hole about 5-6mm dia from the transfer gallery in the crank case down to just behind the main bearing.
Than remove the oil pump and lines and plug it all up.

If it's working alright I'd say leave it there. I've never had an oil pump failure and it saves mixing fuel.
If you're after trophies and you're after that very last bit of advantage fair enough. I just find it so convenient.

Cheers

Brent

[oldfart]

Brent ....what do you do with the hole in the crank ( slinger side ) I was under the impression the slinger plate also acted as a shim

[brent j]

Brent ....what do you do with the hole in the crank ( slinger side ) I was under the impression the slinger plate also acted as a shim

You're right Stu about the shim part of it, I'd simply forgotten . I've updated my post.

As for the hole in the crank, do you mean the one in the crank pin where the slinger fits into?
I'd just leave it as it lets a bit more mixture into the big end.

[DR]

The slinger plate doesn't really do much in regards to being a shim as the crank is locked tight on the right side by the nut on the primary drive. To replace the slinger plate as a shim the factory dimensions are 25x36x0.8 and the part number 08222-25366 (about $2.75) but I know of people who simply removed the plate and bolted it back together with only the spacer showing no ill effects after seasons of racing or some even slip a 0.80mm spacer between the bearing and the outer case which does the same thing  

[suzuki447]

thanks guys i,ve just bought this tm and there is no oil container on bike and cable to oil pump not attached to pump so maybe it has all ready be done.i will check before i start it up ,also if anyone has rear wheel and brake for this i would like to buy one thanks again don.

[brent j]

The slinger plate doesn't really do much in regards to being a shim as the crank is locked tight on the right side by the nut on the primary drive. To replace the slinger plate as a shim the factory dimensions are 25x36x0.8 and the part number 08222-25366 (about $2.75) but I know of people who simply removed the plate and bolted it back together with only the spacer showing no ill effects after seasons of racing or some even slip a 0.80mm spacer between the bearing and the outer case which does the same thing  

Good point on the spacer/shim not really being needed Doc.

[DR]

Brent the only issue I could see is 'possible' premature right main bearing wear. Apparently this doesn't seem to happen but I'd run a shim regardless for peace of mind

[Canam370]

Save the $2.75 and just trim down the slinger  . Like Doc I always run the shim after conversion. I reason the engine was designed to include the spacer so why invite a potential problem?

[brent j]

thanks guys i,ve just bought this tm and there is no oil container on bike and cable to oil pump not attached to pump so maybe it has all ready be done.i will check before i start it up ,also if anyone has rear wheel and brake for this i would like to buy one thanks again don.

Based on what you have said.
I would pull the cyclinder off and look for a hole in the LHS transfer port in the case. If there is a hole going down to behind the main bearing it's been done. If not, I would strip the motor. That's my opinion.

They will run, sometimes for years, with out the oil pump and proper mods but they usually end up stuffing the LHS main bearing and doing a bit of other damage. With out the hole the fuel/oil mixture dies not flow freely around the main bearing.
If the oil pump is there with no cable and no oil getting to it, it may be running dry and be about to expire.

Brent

[DR]

Another method was to run the pump and a smaller tank. Lock the pump lever on the first mark with tie wire/zip tie or whatever. Get rid of the cable, block the cylinder banjo and run premix in the fuel. This means the pump still feeds the bottom end but the top end is looked after by the premix.

[brent j]

I'll have a good look at the set up on the MX90. They ran the small tank to feed the main bearing and had a fixed pump delivery (no cable)

They may have still run the oil feed for the inlet as the pump will only deliver a minimal flow and I think the pump may need somewhere to deliver the oil to stop a pressure build up.

Brent

[DR]

oops, something I forgot to mention with the premix and retained oil pump. Suzuki recommended the feed should be swapped at the pump so the feed for the inlet thus becomes the feed for the bottom end. The bottom end feed should then be blocked. Don't ask me why as they seem to pump exactly the same amount. My take on this was Suzuki trying to make it sound more complicated that it actually is thus people would either leave it as is or buy the MX kit conversion. No-one has ever said why but now it is making a little sense. Could it be the inlet feed isn't pressurized or has a relief setup?? maybe! US Suzi expert Joe Broussard on the Yahoo TM group maybe able to answer but I can't see the reasoning except as above.