Help required - gray smoke and engine rattle

[AgentX]

Probably the long way around..but still good news...if he can get the 350 case...and maybe ship it over to those other cats to have it worked into a 500?...same way they mod their current 350 cases...but thats just me ice skating up hill...who knows..tomorrow they may get some cases in...

Price Part gets the cases from India, modded in India.

[wernwilk]

again great suggestions guys.

as an update, I spoke to Henry price at Price parts in the UK, he just got some stock in but;

a) They are for the kickstart model and can be tricky to modify for the electric start model due to the engine mountings being different.

b) They have now gone up to 250 pounds sterling, I understand this is due to increased machining and shipping costs from their supplier.

Henry was really nice and helpful but looks like the milled out 350 will not work for me in this instance.

i tried a few of the indian dealers and only found a complete motor for $2600.
However!!  I did manage to find the wholesaler in Minnesota who have a set of 2 crankcases in stock for $375 plus shipping.

I ordered them and also a full gasket set plus new main bearings and crankshaft oil seals.

can anyone think of or recommend anything else I will need provisionally for the rebuild?  Obviously this will be determined by what I find upon getting the motor apart.

[maxrotor Afro Samurai]

Well thats good news...

Sounds like you are still short a jack hammer...
And 55 gal drum pb breakfree...

[wernwilk]

Update on the project.

The details of this are in the prior posts.
I have gotten the head off finally with the use of quite a bit of heat...which I had tried that before the clamp option which resulted in the bust crankcases.

I have now pulled the motor and am beginning to strip the old cases down to switch components over to the new ones.

On inspecting the piston, it is scored pretty badly but all the rings are intact....it looks to me like a series of seizures have occured....the barrel is also scored and i will look at options for reboring and a replacement piston - all suggestions welcome.

Now I want to explore what caused the seizures...is this a common problem with the bike?  What are the main causes?

Thanks all.

[maxrotor Afro Samurai]

Very good question...i have the same concern of wanting to know why this happens ...seemingly so often...
Some places point to abuse during break in procedure which is extremely slow and frustrating (i am going throught it now.. hard to fight temptation.. hope i dont pay for it later.. but im not too bad)..

Other places say heat..but if this bike can survive india how the heck is the stupid motor locking up  in the US?..are the Indians that diligent in the break in procedure?.. or maybe road conditions are so bad that they dont go fast anyway?.. seen clips on net with guys speeding along... seems like road sides would be full of dead bikes with all the heat and traffic they see..

Then.. someplace in snidals book... he states where typically when an engine seizes.. in some cases once it frees up again.. people simply keep on riding.. keeping speeds low etc.. and never bother with the rebuild...

Man.. im am at a loss.. i really dont understand why this problem occurs..here and not everywhere all the time 24 hrs a day..... and I am hoping.. that switching to alloy barrel.. adding oil cooler etc will totaly eliminate this problem in the future...for everyone...

[wernwilk]

So I have the crankshaft out...I will be putting the crank in the freezer and the main bearing inner races in the oven for fitting.
The big end feels good with no vertical play.
Is there anything else I need to look out for on this engine before re-assembling the crankcases?

I will be servicing the oil pump also before re-fitting the timing cover.

Any help would be good as I do not want to have to pull this motor apart again.

Also, I will be needing a rebore more than likely as the barrel is scored where the soft seize occured, any recommendations as to size of bore and oversize of piston  etc??

thanks all.

[barenekd]

Seizures occur when the piston overheats because of lean mixtures (pinging), too advanced ignition (Preignition), or a lack of adequate piston/cylinder clearance when the engine was assembled. The iron barrels expand more slowly than the aluminum piston as the engine heats up. This is the advantage of the alloy barrel, the expansion rate is the same between the two parts. The piston to liner clearance should nominally be about .005" at the top of the slotted piston skirt. A solid skirt should have .002 additional clearance. Those are minimums, if you tend a ride the bike hard another thou or two clearance can't hurt. Ring end clearance should be about .015"
Bare

[wernwilk]

thanks for that info...it sounds like an alloy barrel is the way to go...however if my friends budget will not stretch to that...can anyone recommend good oversize pistons to match a rebore on the old steel barrel?

[Blltrdr]

thanks for that info...it sounds like an alloy barrel is the way to go...however if my friends budget will not stretch to that...can anyone recommend good oversize pistons to match a rebore on the old steel barrel?

I would go with the ACE piston or the one that Tim in NZ recommends.

[wernwilk]

An update,

the crankcases are al back together with the timing cover on etc.

I am now hoping to sort out the top end.

currently I need a standard piston and rings, the bore in the old steel barrel has some marks in it and one place where a small score can be felt, it is not deep.

What is recommended in this case, could we get away with a new piston and rings and not a rebore?  As I said the marks are there and not deep, in fact only the one can be felt.

I looked at n'field gear and the piston sets seem expensive, ($260), however I looked at the Price parts prices and there are standard pistons for 80 pounds sterling which is $137 USD.

I am going to be in the UK and fairly close to Price parts over Christmas so can pick parts up without need of postage/shipping.

Any feedback welcome please.

[wernwilk]

Hi all,

so in not finding any clear engineer shops in Sacramento, (hard to believe but I simply cannot find one here), I have decided to have a go at honing the seizure marks out of this bore myself.
As mentioned before the marks are not at all deep and their is just one slight score mark that can be felt to the touch.

Does anyone have any advise or experience on technique for this/ equipment or choice etc....?

Thanks.

[barenekd]

The latest thing on boring and honing is to leave the cylinder smooth. honing cross hatches is out, as they just increase the initial ring wear considerably.
As far as to whether or not you need a new piston and/or a bore job, you need to measure the bore and the taper and see how much clearance you will have with a new piston. If the cylinder has much taper or out of roundness, you are definitely going to need a bore.
If you can't find a machine shop that bores motorcycle cylinders in Sacramento, call Big Al (Tri750) (BMW/Enfield of Fresno) in Fresno and see who he recommends.
Bare

[wernwilk]

thanks for the advice bare,

regarding the piston, the skirts and rings have seizure marks on them and so I will replace them.

The bore is smooth apart from the a couple of spots so I wanted to a machine shop to take a look as i do not necessarily trust my own measuring abilities.  What should I be looking at and whats the process for measurement?
I.e:  What do I measure and where...what are my tolerances?
I believe the standard piston is 84mm, am I correct?

Thanks.