81 Interstate conversion into sport cruiser

[sonoramike]

I've been wanting to do this for awhile. Surf Craigslist ads now and again for a viable candidate. Late last summer I picked up an 85 Interstate with 48k miles in great shape for $1000 and have been going through it, not fully on the road yet but should be shortly after I get the carbs back together.

Late last week I ran across an ad for an 81 for $500 running with title, but kinda rough. Saw it last Friday, the starter was inop and it has had head gasket issues due to a bad thermostat switch that caused an overheat (those switches are expensive!) but it seemed a solid base for a thinned down around town bike that I've had designed in my head so I handed the man his cash and loaded it up for the long ride home.

Ordered a starter on the way home Friday night. Stripped it all down over the weekend, took it to the car wash to get the grime off it Saturday. Starter arrived this morning, having done a starter R&R on the 85 before so I made quick work of it knowing what I needed to do. Once in all it took was one revolution of the starter and it popped alive. Photos and updates to come

[77Gowing]

That's great. Hope it all works out for you
.
I wanna see the pics.

[Track T 2411]

Welcome from Wisconsin. Sounds like a couple of great buys! Enjoy the ride!

[sonoramike]

Saturday morning after dragging her home the night before, took the rear saddlebags off before realizing I needed to take a photo or 2.



Ended up leaving her in the truck to strip it, no need to take it out and then reload the big beast, now naked, even the dog is excited



So dirty. Looks like the cases have been apart due to white RTV between the case halves and the clutch cover and more. 80k miles on it

On order:
Emgo chrome superbike bars - 23-12561
Renthal grips
Kawell bar end mirrors
K&L fork seals and 1 OEM upper fork bushing, the throttle side fork is lightly blown, going to pull them both apart and freshen them up
Exhaust/muffler - I cut the stock pipes at the join point on the stock exhaust manifold in front of the baffle, going to fab up a midpipe at an angle to match the backside of the frame as it heads up to the seat and bolt these to the stock mount point. Need to shoot a few photos of this
Exhaust header - degrease and smooth the attachment points on the manifold for the chrome covers that no longer exist. Paint exhaust manifold flat black as well as the midpipe, hopefully it will all blend well

Undecided:
seat - I like the ducati monster seat fab, but there seem to be a lot of seats ready to go on ebay
headlight bucket - off to shop 7" buckets at ebay here in a few
blinkers - need to pick a style I like, prob old school stock looking aftermarkets, keep it simple
headlight ears - I'd like to do an oldschool set of ears with the ears and headlight bucket painted the same color as the tank and fenders. Have found a few on ebay
fender cutting
paint color - currently black, but its beat up. I like the light Honda blues
seat grab bar - been
wheels - paint entire wheel an alum color, or leave stock black/chrome lip and spoke circles

todo:
head gaskets and basic internal inspection
clutch basket adjust - prev owner reported that the clutch started to slip when on the gas hard in "5th and 6th" which is unusual for a 5 speed bike... Must have had an upgrade along the way...
replace front tire
check rear tire date code, is pretty new per PO, trust but verify...

Long term:
get it on the road and riding now
address one area at a time to keep it riding
have fun

[Rat]

Welcome to the 'Wingdom.

Sounds like you’re well on your way .... ShopTalk has lots of good info ....

Gord

[sonoramike]

@RAT, shoptalk is a great resource. Logged a few hours going through it all, more to go. Thanks for mentioning it

[sonoramike]

so bad news, bad news, and a question amidst the pain

Started the bike at least 8 times yesterday, worked a charm each time, very impressed with how quickly the bike popped alive. Walked by it this afternoon and decided to just fire it up and enjoy the burble of open pipes. ZZZZZZZZzzzzzzz when the starter without engaging. me: push the button again, same. repeat 3 or 4 more times. Never catches. Huh, starter gear must not be fully engaged with the gear splines - but starter went all the way to the seat on the body where it mates with the block. Ok, I'll R&R it again, easy enough. Pull the starter out, no visible indication of anything on the starter gear - no stripped teeth, nothing polished from rubbing at the top of the gear. Line it all back up and this time after a moment or 4 it pops right in all the way in one stroke. I bolt it in but leave the header off of it, want to see what is going to happen. Turn the red run/stop switch to stop and hit the button. it turns over. me: cool. button the exhaust back up, flip the run/stop to run and hit the start button. it pops right away and dies, no choke. Give it some choke and give it another go ZZZZZZzzzzzz. Bad words were heard in that moment.

Occams razor says that the simplest reason is usually the right reason, so that would be that the starter splines are not fully seating somehow into the gear in the case. So to prove this I'm going to put an o-ring on the starter splines about 1/4 down from the top on the R&R and see what happens. If it ZZZZZZZZzzzzz's again then pull the starter and see what the o-ring tells me.

Bad news 2: I've been seeing a slow drip oil leak coming from above the shifter arm off the bottom head bolt. Noticed a bit of white RTV on/around that bolt yesterday, so today I got the small screwdriver out and went to work to see what was under all that RTV since no good can ever come from RTV. Sure enough, the head is cracked at the ear, lousy cell phone pic of the screwdriver tip pointing to the crack



So I need to source a head, will any 1100 L side head work? ie, need interchange info

Looking more and more like I'll be pulling the motor to address things prior to getting it on the road which kinda bums me out, I have too many projects already and this was a bike that was supposed to get me on the road and riding while I build the GT-750 which was supposed to be a runner from day 1 as well...

[flyin900]

Head from either side will work from what I recall. If you can get a complete head with cam and holders great. You need the original cam holders at a minimum with the new head.
You may have an issue with the starter clutch not engaging properly. A common issue on these bikes especially after they have sat awhile. It could be an issue with the starter installation, yet they only go in one way and if the starter gear and chain look good I would consider a starter clutch issue.
If you can get it running again an oil change and something to clean the motor internally like a Seafoam mixed into the oil in the correct volume per the can and running the bike at idle. This may help in cleaning and loosening up the rollers and pins in the starter clutch.

[robin1731]

^^^^^^What he said.^^^^^^^ Any 1100 head will work. The cams are what make them RH or LH.

And yeah, sounds like the starter clutch. I wouldn't call it a common problem but it happens. Hopefully what flyin900 suggested works. The real "fix" requires engine to come out.

.

[ericheath]

I had a head with same issue. The crack probably extends down to the bolt at the bottom. I cleaned mine up will with acetone and used JBWeid to get through the summer ones year. The crack was visible on the inside and because a good flow of oil flows there leaks quite a bit. I think I did it without removing the head using a q-tip through the lower opening. Not recommended for long term but could keep you working on it and checking further items

[sonoramike]

Head is coming off to replace the head gasket anyway , I'll have a look at the crack then and see if I can patch it or if I need a new head, clean all that baked on oil off the block then too, i hate a dirty mess, hides things like this. Think I've just bought a bike that has been maintained by a sloppy mechanic, which means trust nothing, confirmed by all that RTV usage, that reeks of cutting corners and being cheap.

The starter issue is what has me a bit bummed out at the moment,. Even if the oring test shows that the gear is partially pushed down the splines , which doesn't make sense given the intermittent nature of the problem, I'd have to take the back cover off to fully seat the gear onto the splines. Can't ride a bike anywhere that has an intermittent starter, not wiling to be stranded. And it has to start in order to get the seafoam into it to have a chance to free the starter clutch up.

[Rat]

Sounds like the starter clutch to me .... there are a number of approaches to cleaning it up that don't involve pulling the motor .... a quick search will give you the ideas

Gord

[ericheath]

If you’re pulling the head to replace the head gasket, replace the head. You can find them cheap. eBay.

[dontwantapickle]

Seeing RTV on a bike is always a huge red flag for me.
It shows me that the "mechanic" didn't pay attention to the details while "fixing" whatever
they went inside to fix.

[sonoramike]

Seeing RTV on a bike is always a huge red flag for me.
It shows me that the "mechanic" didn't pay attention to the details while "fixing" whatever
they went inside to fix.

concur 1,000%. Didn't think to look under the bike to see if the halves were RTV'd. But truth told I prob would have pulled the trigger on it even if I did see RTV there.