startup problem with warm bike

[peltsu]

I have a problem:

My bike doesn't start when warm, when it's cold it starts easily

I have done several things:
- Carbs are cleaned very well (problem also occured before cleaning )
- The engine is overhauled in last winter (new piston rings, bearings etc.)
- A brand new battery

Here is the mystery: If I push start it, it starts easily. But if I try to use a starter motor, it doesn't start no matter what. I have also tried a starter booster to make sure that there will be enough juice to spin starter motor fast enough. But no help.
The bike runs very well when warm, it's only if I turn it off and try to start it again.

Any idea?

By the way, I live in Finland where Vision is extremely rare bike, so getting spare parts is a nightmare.

[ps2/bikevision]

sounds like a bad starter. mine was doing that when i first got it. put a new starter in it and she was good as new. id take the starter out and bench test it. could be full of oil too.

[Rick G]

Hi Peltsu, where did you get your pistons and rings, what over size did you use  and what did they cost.There's none of that available in North America.

[peltsu]

For more precise diagnose: Starter motor spins pretty good when warm, but the bike just don't like to start. As I mentioned I tried to use a proper starter booster (it can start truck engine with dead battery) and then starter cranked pretty fast, but no help.

I have original pistons and cylinders as they were in good condition, I just honed cylinder bores and replaced rings and all engine bearings, gaskets etc.
If I remember correctly the crankshaft bearings are from some Mitsubishi as it's machined to different size as original.

Starter seal is also replaced and at least then it wasn't full of oil. I'll have to check it again. Next I'll have to try to supply voltage to TCI from a different battery and to the starter from another, so I can rule out low voltage situation completely.

[GT @ oh.]

I've heard talk that vapor lock is some what common on V's and putting petcock on prime may help as well as putting something on the bottom of the tank to reflect heat from engine....Also removing fuel cap in case its the vent blocked in the cap..... Just thinking out loud here...

[Lucky]

If the starter seal was replaced, i'll bet the drive gears are a tooth off. mine ran a week or so before i wiped out the starter...

[QBS]

V carbs are really sensative to proper adjustment.  If they are jetted wrong, not well synched, or the pilots are not set right, hot starting can be a problem.  I think this is true for both years.  My '83 can be tempermental when starting hot.  One thing you really don't do is give the bike any gas when starting from hot.  Just push the starter button only.

Suggest you carefully synch the carbs, retune the pilot jets, make sure your jetting is correct.  Also, clean your low tention spark coil connections and possibly replace your spark plug caps.

From what you have already posted, I'm not inclined to see a starter motor problem.

[peltsu]

Do you have any idea is there any chance to find the same starter from any other bike? As I mentioned here in Finland Vision is very very rare bike as it was sold only in -82...

OT:
I have replaced rear wheel with 750 Virago's wheel (rim+tyre), seat is new, rear fork bearings are custom made, front fairing is from some Honda (CBR if I remember right). And now after cleaning carbs and engine overhaul it runs very nicely (beside that you can't turn it off when you stop to coffee etc. or you'll have to wait about 2-3 hours to cool off engine :)

[macroars]

xz550 seems rare in Norway to, but there are several for sale in Sweden. There might be easier to find parts there.

Regarding starter: Try to open it up and have a look before concluding. I removed some dirt and loosened the brushes - and it was ok again. A really easy thing to have a look into. Lift the bike as much you can in the front to avoid to much oil to drain from the hole. ROV provides a good guide: http://www.ridersofvision.net/Technical/Starter/starter.html

[Walt_M.]

My '83 has much the same problem, but only if I park it on the sidestand so I use the centerstand only. My carb floats are probably set too high and flood it somehow if I put it on the sidestand. I will look into it some day.

[ps2/bikevision]

you may be running to low of octane, not sure what you guys have over there but i know with mine if i use less than 91-92 octane it will start hard when hot. once i started using the highest octane my hot starting problems quit and it also stopped heating up when in stop and go traffic.

[Rick G]

Then again , mine starts fine when hot , on any grade of gas.
It suffered a hot start failure,  many years ago in OR.  I just opened the throttle and cranked it a couple of times , before it would start.

[peltsu]

you may be running to low of octane, not sure what you guys have over there but i know with mine if i use less than 91-92 octane it will start hard when hot. once i started using the highest octane my hot starting problems quit and it also stopped heating up when in stop and go traffic.

Here we have only 95 and up, I'm using 98 (1,4 Eur/litre or 8,4 USD/gallon :( )

I opened up starter yesterday but I didn't notice any damage etc. but there was some dirt which I removed. Drive gears were fine and on their place.
I haven't tested it yet, but let's hope that cleaning would cure the problem. I don't think the problem can be in carbs because it push starts pretty easily.

[Walt_M.]

That sounds like a failing battery or charging system problems. Do you use a battery charger at home?

[peltsu]

Problem solved: It was either dirt in starter or slipping starter clutch. Starter clutch was slipping (freewheeling) once in a while as there was cracks in the flywheel.