Oil Recommendation

Hi Guys,

I've got a 1981 XJ750 (the picture in my avatar) that I ride every day (I live in Southern California). I put about 12,000 miles a year on it. It currently has 84,000 miles and runs well - no problems... until a few weeks back. I changed the oil (which I do every 3000 miles) and decided to put full synthetic in (Shell Rotella T6) I did this after reading a lot about the benefits of synthetic. However, just after the oil change I noticed that the starter would slip but only if the engine was warm. When I started the bike in the morning - no problems - but if I rode 6 miles to Walmart to pick up a donut to take to work - the starter would slip and I had to push start it.

I remember reading in this site that sometimes synthetic oil would cause the starter clutch to slip because it was so slickery... So 2 weeks ago (after only 150 miles with the synthetic - I drained that oil and put in my regular oil - Rotella T4 (15W-40). However, I had the same issue with the slipping starter clutch, so last week I drained the T4 oil and decided to put in Rotella T1 (straight grade 30 weight).

So now I think the starter clutch is working fine - no more slipping - however last night on my ride to school (45 miles) and also on my ride back home after school, there were 2 times when I could not shift into 5th gear. It was like the transmission was stuck in 4th and would not allow me to shift into 5th. I was able to downshift into 3rd and finally able to coax it into 5th - but I've never experienced that issue before.

I'm planning on draining the current oil (straight 30 weight) and putting the T4 (conventional 15W-40) back in... but I'm confused about the straight 30 weight - why would that cause my shifting to bind up????

Also - I know my bike is getting "long in the tooth" - and that someday I will have to split the case and fix the starter clutch the right way - but I'm hoping to postpone that as long as I can so I'll stay away from synthetic oil for now.

Thanks,
-Rustee

 

Oil link in my signature.

It sounds like you may have a alternator chain guide that's come apart, preventing that shift into fifth. Do a search for Emergency Guideectomy.

 

Recommend pulling exhaust system and dropping oil pan , this will allow you to see any chunks in bottom of pan . Synthetic will do bad things to a high mileage engine .

 

If the chain guide has turned to shrapnel, you'll have the opportunity to do the starter clutch at the same time, as each requires splitting the cases.

 

Here...

https://www.xjcd.org/emergency_guidectomy

 

What if I don't have a coat? Will a scarf do?

 

Only a particular scarf may be subsitiuted.

 

Thanks for all your suggestions. Today I drained the oil and looked inside the engine with an endoscope I bought online for $20 through the oil drain plug hole. Everything inside looks fine. Transmission gears look good and no sign of any broken chain glide. Shifting is fine as well. No debris in the oil. So I guess I'll just keep riding...

 

It is very possible that the oil was giving you the issues. I have no trouble attributing it to that

 

I'm hoping it was the synthetic oil that caused the problems... I understand why the starter clutch might slip, but why would shifting into 5th be affected by synthetic?

 

tell me about that thing. i almost bought one several times.
about 5th gear, there's a hundred places a chunk of rubber could get stuck and never make it down to the oil pan

 

The endoscope is awesome. Plugs into my android phone or tablet. Has a built in light. The cord is stiff so it can snake around and keep its shape. Picture on the phone looks great with great detail.

 

Well - that didn't last very long. As I was coming home from school last night, the transmission locked up in first gear. I had Triple A haul me the 42 miles back home. This morning I pulled the shifter plate and found two pieces of Bakelite jammed into the shifter drum - I suspect I will find more.

So I guess I'll be pulling the engine sooner than later...

Is there a nice write-up somewhere on what I should look for once I get the engine apart (as far as things that should be checked and replaced on an engine with 85,000 miles)? I noticed that one of the chain guides and the chain itself is obsolete on Partzilla.com - Does Chacul carry all that stuff?

Would I be better off finding a gently used engine?

Does Steve R. want to sell his bike that is in the Showcase? (the white one with factory hardbags and sport fairing)?

-rusteeGold

 

I thought I'd post some pictures using the endoscope. I stuck the camera into the small hole just above the shifting drum. You can see the cam chain and the broken glide. The other picture is the broken piece of glide. It's about the size of your thumb.